This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells,walnut shells,and carbonfibers dispersed in a polyester matrix.MINITAB(L16)Taguchi experi...This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells,walnut shells,and carbonfibers dispersed in a polyester matrix.MINITAB(L16)Taguchi experiments were used to determine the optimal combination of parameters.In particular,an erosion device con-sisting of a motor with a constantflow rate of 45 L/min,a pump with a diameter of 40 mm,a nozzle with a dia-meter of 5 mm,and a tank made of“perspex glass”55 cm long,30 cm tall,and 25 cm wide was used.The tests were conducted by varying the sample-to-nozzle distance,the pattern angle,and the sand particle size.The results have revealed that the presence of 7.5%by weight of waste coconut shell,for conditions corresponding to 90°angle,sand size 425μm,stand distance 30 cm,gives the best wear resistance(3.04×10^(-5) g/g).Thefiller content and sand particle size affect the erosive rate,with the angle playing a secondary role.The distance between the sample and the nozzle has a weaker effect on erosive wear.The hardness results show that the models(UP-5%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste coconut shell)give the best values for prayer compared to the samples(UP-5 wt.%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste walnut shell).展开更多
Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by...Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.展开更多
The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fib...The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fibers as reinforced material,under the condition of adding graphite or carbon black respectively,the composites were manufactured.The flame retarding and antistatic properties are also studied.In the experiment,bromide-bearing flame retarding resin decomposed under a high temperature.Compound HBr was set out and retarded or stopped the flame.High concentration of HBr gas wall was formed between gas and solid phrases,which decreased flame.The results show that antistatic property of carbon black is higher than that of graphite.Adding a threshed value of 1% carbon black into composite,the antistatic property is at its highest value.展开更多
In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester res...In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.展开更多
The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the 'reaction method', by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP lo...The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the 'reaction method', by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP long chain. The performance of the nano-TiO2/UPR was determined by such a new structure. The research results showed that the reactivity of nano-TiO2/UPR is higher than that of UPR. The impact strength and bending strength of nano-TiO2/UPR are greatly enhanced as compared with that of UPR. Thermal resistance and dielectric property of nano-TiO2/UPR are the same as that of UPR.展开更多
Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray dif...Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame retardance.The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA.Moreover,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much decreased.In addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and dehydration.Furthermore,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the SSA.In sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.展开更多
The reduction action mechanism of unsaturated polyester resinreducer is analysed. The experimental results show that the activereducer bearing reactive functional group on the ends of moleculeseffectively lowers the c...The reduction action mechanism of unsaturated polyester resinreducer is analysed. The experimental results show that the activereducer bearing reactive functional group on the ends of moleculeseffectively lowers the curing shrinkage of unvaturated polyesterresin.展开更多
The reduction action mechanism of the unsatrurated polyester resinreducer is analysed by the free space volume theory. Throughmeasuring the reduction magnitude in each phase of solidification,the authors predicted the...The reduction action mechanism of the unsatrurated polyester resinreducer is analysed by the free space volume theory. Throughmeasuring the reduction magnitude in each phase of solidification,the authors predicted the rate of reduction is in concordance withthe results from experiments. From this we presented corre- spondingsolutions to different causes of the reduction action of theunsaturated polyester resin.展开更多
The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize th...The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize the material of the water collector and improve its mechanical properties.Polyester,a general term of polymer obtained from polyols and polyacids,is a kind of engineering plastics with excellent properties and wide applications.Glass fiber is a reinforced plastic reinforcement material,and the biggest characteristic of it is the high tensile strength and good heat resistance.In this paper,glass fiber reinforced polyester resin composite material is prepared,its tensile properties and bending properties are tested,and the performance of the imported material JK2020B is compared and analyzed.The results show that the elastic modulus along the fiber direction is relatively high,but the interlayer force in the direction of thickness and width is very small.This review provides a guidance for production process.展开更多
Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that...Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that is highly consumed in reinforced composites for its superior mechanical strength. As opposed to that, flax obtained from flax stalks can be used as an alternative reinforcing material with synthetic fibers to minimize manmade fiber consumption. Hence, this research work addresses a few flax/glass-reinforced hybrid composites by using a thermoset polyester matrix. Here, six categories of samples are made, like neat flax, neat glass, and flax/glass fabric reinforced hybrid composite, followed by different stacking layer sequences and hand layout techniques during processing. Afterwards, the mechanical behavior, thermal stability, morphological behavior, and water absorption of hybrid samples were investigated. Among the developed samples, neat glass (NG) composite exhibits superior mechanical properties, while neat flax (NF) shows the lowest result. It is apparent that the mechanical properties and thermal stability of hybrid samples are in between NF and NG because, by adding glass with flax fabric, the strength of hybrid samples is increased. Moreover, it is noticeable that, due to multiple stacking layers of flax and glass, hybrid 3 and hybrid 4 show better strength than consecutive single stacking layers in hybrid 1 and hybrid 2. Among all hybrid composites, the H4 shows comparatively better mechanical and thermal properties due to having the glass layers on the outermost surface. In summary, this research work demonstrated the feasibility of flax fabric with glass fabric as a reinforced hybrid composite that can be used in automobile inner bodies, household furnishing, and home interior decoration.展开更多
Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that...Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that is highly consumed in reinforced composites for its superior mechanical strength. As opposed to that, flax obtained from flax stalks can be used as an alternative reinforcing material with synthetic fibers to minimize manmade fiber consumption. Hence, this research work addresses a few flax/glass-reinforced hybrid composites by using a thermoset polyester matrix. Here, six categories of samples are made, like neat flax, neat glass, and flax/glass fabric reinforced hybrid composite, followed by different stacking layer sequences and hand layout techniques during processing. Afterwards, the mechanical behavior, thermal stability, morphological behavior, and water absorption of hybrid samples were investigated. Among the developed samples, neat glass (NG) composite exhibits superior mechanical properties, while neat flax (NF) shows the lowest result. It is apparent that the mechanical properties and thermal stability of hybrid samples are in between NF and NG because, by adding glass with flax fabric, the strength of hybrid samples is increased. Moreover, it is noticeable that, due to multiple stacking layers of flax and glass, hybrid 3 and hybrid 4 show better strength than consecutive single stacking layers in hybrid 1 and hybrid 2. Among all hybrid composites, the H4 shows comparatively better mechanical and thermal properties due to having the glass layers on the outermost surface. In summary, this research work demonstrated the feasibility of flax fabric with glass fabric as a reinforced hybrid composite that can be used in automobile inner bodies, household furnishing, and home interior decoration.展开更多
The effects of moist and temperature response of coconut fibre reinforced composite have been studied. Tensile and compression tests for samples immersed in 12.5 g/dm3 sodium hydroxide solution and without sodium hydr...The effects of moist and temperature response of coconut fibre reinforced composite have been studied. Tensile and compression tests for samples immersed in 12.5 g/dm3 sodium hydroxide solution and without sodium hydroxide solution were performed using a universal testing machine (Monsanto tensometer). The results from the tensile test indicate that stress is fairly proportional to strain. However, the tensile strength increases (reduction in strain), as the soaking time increases for the treated composites. The untreated samples demonstrate reduced tensile strength compared to the treated composites under hygrothermal conditions. The conditioned samples in each case show better tensile and compressive strength compared to the untreated samples. The plant coconut fibres investigated demonstrate acceptable mechanical properties similar to the synthetic counterparts.展开更多
Glass Fiber Reinforced Polymeric (GFRP)</span><span style="font-family:""> </span><span style="font-family:Verdana;">Composites are most commonly used as bumpers for ve...Glass Fiber Reinforced Polymeric (GFRP)</span><span style="font-family:""> </span><span style="font-family:Verdana;">Composites are most commonly used as bumpers for vehicles, electrical equipment panels, and medical devices enclosures. These materials are also widely used for structural applications in aerospace, automotive, and in providing alternatives to traditional metallic materials. The paper fabricated epoxy and polyester resin composites by using silicon carbide in various proportions along with GFRP. The hand lay-up technique was used to fabricate the laminates. To determine the properties of fabricated composites, </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">tensile, impact, and flexural tests were conducted. This method of fabrication was very simple and cost-effective. Their mechan</span><span style="font-family:Verdana;">ical properties like yield strength, yield strain, Young’s modulus, flexural</span><span style="font-family:Verdana;"> mod</span><span style="font-family:Verdana;">ulus, and impact energy </span></span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> investigated. The mechanical properties of the</span><span style="font-family:""><span style="font-family:Verdana;"> GFRP composites were also compared with the fiber volume fraction. The fiber volume fraction plays a major role in the mechanical properties of GFRP composites. Young’s modulus and tensile strength of fabricated composites </span><span style="font-family:Verdana;">were modelled and compared with measured values. The results show that</span><span style="font-family:Verdana;"> composites </span><span style="font-family:Verdana;">with epoxy resin demonstrate higher strength and modulus compared to</span><span style="font-family:Verdana;"> composites with polyester resin.展开更多
Polymeric ester thiourea resin (PDTU-I) is a new kind of chelating resin with functional atoms S, N and O, so it is an excellent adsorbent for noble metal ions. In batch testes, the adsorption capacities of PDTU-I for...Polymeric ester thiourea resin (PDTU-I) is a new kind of chelating resin with functional atoms S, N and O, so it is an excellent adsorbent for noble metal ions. In batch testes, the adsorption capacities of PDTU-I for Pt(IV) and Pd(II) increase with the increase of contact time, temperature and initial concentration of metal ions. The adsorption data fit Boyd's diffusion equation of liquid film, Langmuir adsorption isotherm and Freundlich adsorption isotherm. The maximum adsorption capacities calculated by Langmuir equation are 2.54mmol/g for Pt(IV) and 4.88mmol/g for Pd(II). According to FTIR and XPS results, functional groups of PDTU-I coordinate with noble metal ions in the adsorption process.展开更多
This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin (thermosetting resin) was used w...This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin (thermosetting resin) was used with two types of mineral fillers (dune sand and crushed sand), and with the addition of a marble powder to ensure the continuity of the particle size mixing granular. The lack of the methods for developing this kind of composite materials, had led us to perform an initial experimental approach to define the experimental field, that is to say determine the mass proportions of the various compounds of mixture of our study. In the second approach, we have established and implemented fully experimental plans with three factors namely: factor (1): sand, factor (2): resin, factor (3): marble powder. Test results being the density of polymer concrete and the mechanical resistances. Finally, multi-parameters regression allowed us to determine predictive mathematical models for the different responses of the study. Tests results showed that at three days we got a tensile strength of about 16 MPa with a resin concrete density of 1.9 g/cm3. This shows the advantages of this material.展开更多
A new corona protection varnish was prepared by using epoxy/montmorillonite nanocomposite and pure epoxy resin as adhesives respectively.The adhesive with different amounts of organic montmorillonite(OMMT) was mixed...A new corona protection varnish was prepared by using epoxy/montmorillonite nanocomposite and pure epoxy resin as adhesives respectively.The adhesive with different amounts of organic montmorillonite(OMMT) was mixed with 1200 mesh silicon carbide(Si C) by different weight ratios.The surface states of the varnishes with various adhesives were observed by powerful optical microscope.Some properties of the varnishes were analyzed during the enduring time under 5kV/cm DC,such as the relation of change in nonlinear coefficient,natural surface resistivity,and surface temperature variation.The results showed that the amounts of OMMT had little effect on the natural surface resistance of the varnish but had important influence on the nonlinear property of the varnish.When the range of the OMMT content was 2wt% to 6wt%,the nonlinear coefficient of all materials with epoxy/OMMT nano-composite adhesive was higher than that with pure epoxy resin adhesive.The surface temperature of the varnish with epoxy/OMMT nanocomposite adhesive was all lower than that with the pure epoxy resin adhesive under high electrical field strength.展开更多
Nano-silica treated with different kinds of coupling agent (KH550, A-143, A-151) was used to modify the surface condition of glass fiber, and then, the modified glass fiber/unsaturated polyester resin (UPR) compos...Nano-silica treated with different kinds of coupling agent (KH550, A-143, A-151) was used to modify the surface condition of glass fiber, and then, the modified glass fiber/unsaturated polyester resin (UPR) composites materials were prepared. Scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and impact test were used to characterize the composite materials' structure and properties. The morphology of composite materials shows that the adhesion between nano-silica and glass fiber is improved when silane coupling agent is added in. The DMA and impact test results show that silane coupling agent (especially KH550 and A-151) could effectively improve the composite's mechanical properties. When the dose of KH550 was 0.1% (m : m), the storage modulus and impact strength reached the maximum.展开更多
1 Introduction In the GRP (Glass fibre Reinforced Product) industry Cobalt Octoate is the promoter of choice for cross-linking unsaturated polyester (UPE) and styrene monomer.UPE's are often prepared to contain a ...1 Introduction In the GRP (Glass fibre Reinforced Product) industry Cobalt Octoate is the promoter of choice for cross-linking unsaturated polyester (UPE) and styrene monomer.UPE's are often prepared to contain a concentration of 0.04%-0.05% of Cobalt ions so that faster cross-linking of the resin is achieved and ultimately faster manufacturing of the GRP component is achieved.These products sometimes fail prematurely after being manufactured and dispatched to the end user.The influence of Cobalt Octoat...展开更多
Curing behaviors of the unsaturated polyester resin (UPR) containing 1-1.8 wt% methyl ethyl ketone peroxide (MEKP) initia- tor are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP...Curing behaviors of the unsaturated polyester resin (UPR) containing 1-1.8 wt% methyl ethyl ketone peroxide (MEKP) initia- tor are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP systems are examined using the ro- tating viscometer and differential scanning calorimetry (DSC). A liquid fragility parameter, Me, defined as the viscosity varia- tion rate of the liquids towards the curing temperature is presented. It is found that Mc has a good negative relation with the glass transition temperature (Tg) in the systems. Mc can be used for predicting the stability of the cured amorphous systems. The relationship between the liquid and cured thermoset polymer systems is studied from both the thermodynamic and kinetic point of view.展开更多
文摘This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells,walnut shells,and carbonfibers dispersed in a polyester matrix.MINITAB(L16)Taguchi experiments were used to determine the optimal combination of parameters.In particular,an erosion device con-sisting of a motor with a constantflow rate of 45 L/min,a pump with a diameter of 40 mm,a nozzle with a dia-meter of 5 mm,and a tank made of“perspex glass”55 cm long,30 cm tall,and 25 cm wide was used.The tests were conducted by varying the sample-to-nozzle distance,the pattern angle,and the sand particle size.The results have revealed that the presence of 7.5%by weight of waste coconut shell,for conditions corresponding to 90°angle,sand size 425μm,stand distance 30 cm,gives the best wear resistance(3.04×10^(-5) g/g).Thefiller content and sand particle size affect the erosive rate,with the angle playing a secondary role.The distance between the sample and the nozzle has a weaker effect on erosive wear.The hardness results show that the models(UP-5%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste coconut shell)give the best values for prayer compared to the samples(UP-5 wt.%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste walnut shell).
文摘Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.
文摘The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fibers as reinforced material,under the condition of adding graphite or carbon black respectively,the composites were manufactured.The flame retarding and antistatic properties are also studied.In the experiment,bromide-bearing flame retarding resin decomposed under a high temperature.Compound HBr was set out and retarded or stopped the flame.High concentration of HBr gas wall was formed between gas and solid phrases,which decreased flame.The results show that antistatic property of carbon black is higher than that of graphite.Adding a threshed value of 1% carbon black into composite,the antistatic property is at its highest value.
文摘In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.
文摘The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the 'reaction method', by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP long chain. The performance of the nano-TiO2/UPR was determined by such a new structure. The research results showed that the reactivity of nano-TiO2/UPR is higher than that of UPR. The impact strength and bending strength of nano-TiO2/UPR are greatly enhanced as compared with that of UPR. Thermal resistance and dielectric property of nano-TiO2/UPR are the same as that of UPR.
基金Supported by the National Natural Science Foundation of China(51803057)Hebei Province Science Foundation for Youths(E2019508144)Fundamental Research Funds for the Central Universities(3142017099)。
文摘Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame retardance.The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA.Moreover,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much decreased.In addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and dehydration.Furthermore,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the SSA.In sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.
文摘The reduction action mechanism of unsaturated polyester resinreducer is analysed. The experimental results show that the activereducer bearing reactive functional group on the ends of moleculeseffectively lowers the curing shrinkage of unvaturated polyesterresin.
文摘The reduction action mechanism of the unsatrurated polyester resinreducer is analysed by the free space volume theory. Throughmeasuring the reduction magnitude in each phase of solidification,the authors predicted the rate of reduction is in concordance withthe results from experiments. From this we presented corre- spondingsolutions to different causes of the reduction action of theunsaturated polyester resin.
文摘The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize the material of the water collector and improve its mechanical properties.Polyester,a general term of polymer obtained from polyols and polyacids,is a kind of engineering plastics with excellent properties and wide applications.Glass fiber is a reinforced plastic reinforcement material,and the biggest characteristic of it is the high tensile strength and good heat resistance.In this paper,glass fiber reinforced polyester resin composite material is prepared,its tensile properties and bending properties are tested,and the performance of the imported material JK2020B is compared and analyzed.The results show that the elastic modulus along the fiber direction is relatively high,but the interlayer force in the direction of thickness and width is very small.This review provides a guidance for production process.
文摘Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that is highly consumed in reinforced composites for its superior mechanical strength. As opposed to that, flax obtained from flax stalks can be used as an alternative reinforcing material with synthetic fibers to minimize manmade fiber consumption. Hence, this research work addresses a few flax/glass-reinforced hybrid composites by using a thermoset polyester matrix. Here, six categories of samples are made, like neat flax, neat glass, and flax/glass fabric reinforced hybrid composite, followed by different stacking layer sequences and hand layout techniques during processing. Afterwards, the mechanical behavior, thermal stability, morphological behavior, and water absorption of hybrid samples were investigated. Among the developed samples, neat glass (NG) composite exhibits superior mechanical properties, while neat flax (NF) shows the lowest result. It is apparent that the mechanical properties and thermal stability of hybrid samples are in between NF and NG because, by adding glass with flax fabric, the strength of hybrid samples is increased. Moreover, it is noticeable that, due to multiple stacking layers of flax and glass, hybrid 3 and hybrid 4 show better strength than consecutive single stacking layers in hybrid 1 and hybrid 2. Among all hybrid composites, the H4 shows comparatively better mechanical and thermal properties due to having the glass layers on the outermost surface. In summary, this research work demonstrated the feasibility of flax fabric with glass fabric as a reinforced hybrid composite that can be used in automobile inner bodies, household furnishing, and home interior decoration.
文摘Synthetic reinforced composites affect the environment adversely and have become a global concern, causing increased natural composite demand for sustainability and cost effectiveness. Glass is a popular material that is highly consumed in reinforced composites for its superior mechanical strength. As opposed to that, flax obtained from flax stalks can be used as an alternative reinforcing material with synthetic fibers to minimize manmade fiber consumption. Hence, this research work addresses a few flax/glass-reinforced hybrid composites by using a thermoset polyester matrix. Here, six categories of samples are made, like neat flax, neat glass, and flax/glass fabric reinforced hybrid composite, followed by different stacking layer sequences and hand layout techniques during processing. Afterwards, the mechanical behavior, thermal stability, morphological behavior, and water absorption of hybrid samples were investigated. Among the developed samples, neat glass (NG) composite exhibits superior mechanical properties, while neat flax (NF) shows the lowest result. It is apparent that the mechanical properties and thermal stability of hybrid samples are in between NF and NG because, by adding glass with flax fabric, the strength of hybrid samples is increased. Moreover, it is noticeable that, due to multiple stacking layers of flax and glass, hybrid 3 and hybrid 4 show better strength than consecutive single stacking layers in hybrid 1 and hybrid 2. Among all hybrid composites, the H4 shows comparatively better mechanical and thermal properties due to having the glass layers on the outermost surface. In summary, this research work demonstrated the feasibility of flax fabric with glass fabric as a reinforced hybrid composite that can be used in automobile inner bodies, household furnishing, and home interior decoration.
文摘The effects of moist and temperature response of coconut fibre reinforced composite have been studied. Tensile and compression tests for samples immersed in 12.5 g/dm3 sodium hydroxide solution and without sodium hydroxide solution were performed using a universal testing machine (Monsanto tensometer). The results from the tensile test indicate that stress is fairly proportional to strain. However, the tensile strength increases (reduction in strain), as the soaking time increases for the treated composites. The untreated samples demonstrate reduced tensile strength compared to the treated composites under hygrothermal conditions. The conditioned samples in each case show better tensile and compressive strength compared to the untreated samples. The plant coconut fibres investigated demonstrate acceptable mechanical properties similar to the synthetic counterparts.
文摘Glass Fiber Reinforced Polymeric (GFRP)</span><span style="font-family:""> </span><span style="font-family:Verdana;">Composites are most commonly used as bumpers for vehicles, electrical equipment panels, and medical devices enclosures. These materials are also widely used for structural applications in aerospace, automotive, and in providing alternatives to traditional metallic materials. The paper fabricated epoxy and polyester resin composites by using silicon carbide in various proportions along with GFRP. The hand lay-up technique was used to fabricate the laminates. To determine the properties of fabricated composites, </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">tensile, impact, and flexural tests were conducted. This method of fabrication was very simple and cost-effective. Their mechan</span><span style="font-family:Verdana;">ical properties like yield strength, yield strain, Young’s modulus, flexural</span><span style="font-family:Verdana;"> mod</span><span style="font-family:Verdana;">ulus, and impact energy </span></span><span style="font-family:Verdana;">were</span><span style="font-family:Verdana;"> investigated. The mechanical properties of the</span><span style="font-family:""><span style="font-family:Verdana;"> GFRP composites were also compared with the fiber volume fraction. The fiber volume fraction plays a major role in the mechanical properties of GFRP composites. Young’s modulus and tensile strength of fabricated composites </span><span style="font-family:Verdana;">were modelled and compared with measured values. The results show that</span><span style="font-family:Verdana;"> composites </span><span style="font-family:Verdana;">with epoxy resin demonstrate higher strength and modulus compared to</span><span style="font-family:Verdana;"> composites with polyester resin.
基金The National Natural Science Foundation of China(No.20476105)
文摘Polymeric ester thiourea resin (PDTU-I) is a new kind of chelating resin with functional atoms S, N and O, so it is an excellent adsorbent for noble metal ions. In batch testes, the adsorption capacities of PDTU-I for Pt(IV) and Pd(II) increase with the increase of contact time, temperature and initial concentration of metal ions. The adsorption data fit Boyd's diffusion equation of liquid film, Langmuir adsorption isotherm and Freundlich adsorption isotherm. The maximum adsorption capacities calculated by Langmuir equation are 2.54mmol/g for Pt(IV) and 4.88mmol/g for Pd(II). According to FTIR and XPS results, functional groups of PDTU-I coordinate with noble metal ions in the adsorption process.
文摘This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin (thermosetting resin) was used with two types of mineral fillers (dune sand and crushed sand), and with the addition of a marble powder to ensure the continuity of the particle size mixing granular. The lack of the methods for developing this kind of composite materials, had led us to perform an initial experimental approach to define the experimental field, that is to say determine the mass proportions of the various compounds of mixture of our study. In the second approach, we have established and implemented fully experimental plans with three factors namely: factor (1): sand, factor (2): resin, factor (3): marble powder. Test results being the density of polymer concrete and the mechanical resistances. Finally, multi-parameters regression allowed us to determine predictive mathematical models for the different responses of the study. Tests results showed that at three days we got a tensile strength of about 16 MPa with a resin concrete density of 1.9 g/cm3. This shows the advantages of this material.
基金Funded by the Major State Basic Research Development Program of China(No.2010CB736208)the Planning Project of Hei Longjiang Province for Science and Technology(No.GC10A203)
文摘A new corona protection varnish was prepared by using epoxy/montmorillonite nanocomposite and pure epoxy resin as adhesives respectively.The adhesive with different amounts of organic montmorillonite(OMMT) was mixed with 1200 mesh silicon carbide(Si C) by different weight ratios.The surface states of the varnishes with various adhesives were observed by powerful optical microscope.Some properties of the varnishes were analyzed during the enduring time under 5kV/cm DC,such as the relation of change in nonlinear coefficient,natural surface resistivity,and surface temperature variation.The results showed that the amounts of OMMT had little effect on the natural surface resistance of the varnish but had important influence on the nonlinear property of the varnish.When the range of the OMMT content was 2wt% to 6wt%,the nonlinear coefficient of all materials with epoxy/OMMT nano-composite adhesive was higher than that with pure epoxy resin adhesive.The surface temperature of the varnish with epoxy/OMMT nanocomposite adhesive was all lower than that with the pure epoxy resin adhesive under high electrical field strength.
基金Supported by the National Natural Science Foundation of of China(J1210061)
文摘Nano-silica treated with different kinds of coupling agent (KH550, A-143, A-151) was used to modify the surface condition of glass fiber, and then, the modified glass fiber/unsaturated polyester resin (UPR) composites materials were prepared. Scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and impact test were used to characterize the composite materials' structure and properties. The morphology of composite materials shows that the adhesion between nano-silica and glass fiber is improved when silane coupling agent is added in. The DMA and impact test results show that silane coupling agent (especially KH550 and A-151) could effectively improve the composite's mechanical properties. When the dose of KH550 was 0.1% (m : m), the storage modulus and impact strength reached the maximum.
文摘1 Introduction In the GRP (Glass fibre Reinforced Product) industry Cobalt Octoate is the promoter of choice for cross-linking unsaturated polyester (UPE) and styrene monomer.UPE's are often prepared to contain a concentration of 0.04%-0.05% of Cobalt ions so that faster cross-linking of the resin is achieved and ultimately faster manufacturing of the GRP component is achieved.These products sometimes fail prematurely after being manufactured and dispatched to the end user.The influence of Cobalt Octoat...
基金the financial support from the National Natural Science Foundation of China ( 50831003)
文摘Curing behaviors of the unsaturated polyester resin (UPR) containing 1-1.8 wt% methyl ethyl ketone peroxide (MEKP) initia- tor are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP systems are examined using the ro- tating viscometer and differential scanning calorimetry (DSC). A liquid fragility parameter, Me, defined as the viscosity varia- tion rate of the liquids towards the curing temperature is presented. It is found that Mc has a good negative relation with the glass transition temperature (Tg) in the systems. Mc can be used for predicting the stability of the cured amorphous systems. The relationship between the liquid and cured thermoset polymer systems is studied from both the thermodynamic and kinetic point of view.