Phosphorus Containing Rubber Seed oil as a Flame Retardant Plasticizer for Polyvinyl Chloride

The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands.In this study,flame-retardant rubber seed oil-based plasticize(FRP)was prepared via epoxidation reaction and ring opening addition reactions,which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer.When DOP was replaced with FRP,the torque of PVC blends increased from 11.4 to 18.4 N⋅m,the LOI value increased from 24.3%for PVC-FRP-0%to 33.1%for PVC-FRP-20.The THR value diminished from 39 MJ/m^(2)(pertaining to PVC-FRC-0)to 22 MJ/m^(2)Tg increased from 23°C to 47°C,the weight loss of plasticized PVC blends significantly reduced from 22.6%to 2.8%in leaching tests.The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.

The Pyrolysis Experiments of Waste Rubber and Plastics in Rotary Kiln

The pyrolysis experiments were carried out in a continuous feeding rotary kiln pyrolyzer system and the influence of residence time and temperature on the pyrolysis of waste rubber and plastics has been investigated in this paper.It shows that the extent of pyrolysis was maximum when the revolving speed was 1~2r/min and the temperature was 600℃.

Effects of two modification methods on the mechanical properties of wood flour/recycled plastic blends composites: addition of thermoplastic elastomer SEBS-g-MAH and in-situ grafting MAH

The effect of maleic anhydride grafted styrene-ethylene- buty-lene-styrene block copolymer （SEBS-g-MAH） and in-situ grafting MAH on mechanical, dynamic mechanical properties of wood flour/recycled plastic blends composites was investigated. Recycled plastic polypro-pylene （PP）, high-density polyethylene （HDPE） and polystyrene （PS）, were mixed with wood flour in a high speed blender and then extruded by a twin/single screw tandem extruder system to form wood flour/recycled plastic blends composites. Results show that the impact properties of the composites were improved more significantly by using SEBS-g-MAH compatibilizer than by using the mixtures of MAH and DCP via reactive blending in situ. However, contrary results were ob-served on the tensile and flexural properties of the corresponding com-posites. In General, the mechanical properties of composites made from recycled plastic blends were inferior to those made from virgin plastic blends, especially in elongation break. The morphological study verified that the interfacial adhesion or the compatibility of plastic blends with wood flour was improved by adding SEBS-g-MAH or in-situ grafting MAH. A better interfacial bonding between PP, HDPE, PS and wood flour was obtained by in-situ grafting MAH than the addition of SEBS-g-MAH. In-situ grafting MAH can be considered as a potential way of increasing the interfacial compatibility between plastic blends and wood flour. The storage modulus and damping factor of composites were also characterized through dynamic mechanical analysis （DMA）.

Influence of Blending Temperature on Fluorescence Properties of Silicone Rubber Matrix Eu(TTA)_2(phen)(MA) Composites

A series of fluorescent composites were prepared by blending silicone rubber with Eu(TTA )2(phen)(MA). The influence of mechanical blending temperature on fluorescent intensity of composites and dispersion of rare earth complexes in the SiR matrix were investigated. As for the cured rubber, it is found that its fluorescent intensity is relatively low compared with that of uncured rubber. Low temperature is beneficial to dispersion of Eu(TTA )2(phen)(MA) homogeneously. When the amount of rare earth complexes is low, the fluorescent intensity of composites prepared by mechanical blending method above melting point of Eu(TTA )2(phen)(MA) is much higher than that of composites prepared below melting point.

FRACTAL CHARACTER OF PHASE MORPHOLOGY OF HIGH IMPACT POLYSTYRENE/POLY(cis-BUTADIENE) RUBBER BLENDS

Evolution and fractal character of the phase morphology of high impact polystyrene/poly（cis-butadiene） rubber （HIPS/PcBR） blends during melting and mixing were investigated using scanning electron microscopy （SEM）. The characteristic length L was defined as the size of particles of the dispersed phase in blends. Different fractal dimensions, Df and Din, were introduced to study the distribution width of phase dimensions in the dimensionless region and the uniformity of the spatial distribution of particles, respectively. The results showed that the average characteristic length Lm and Df increase as the volume fraction of the dispersed phase increases, when the volume fraction of the dispersed phase is lower than 50%. In other words, the size of particles increases and their distribution in the dimensionless region becomes more uniform. Meanwhile, the uniformity of the spatial distribution becomes more perfect as the volume fraction increases. At a certain composition, Lm decreases in the initial stage of the mixing and levels off in the late stage. In the initial stage, Df becomes large rapidly with the process of blending, which means that the distribution of L in the dimensionless region becomes more uniform. Meanwhile, the spatial distribution tends to be ideal rapidly in the early stage and fluctuates in a definite range in the late stage of the mixing.

Influence of Poly(vinyl chloride) on Natural Rubber/Chlorosulfonated Polyethylene Blends

Blend of natural rubber (NR) and chlorosulfonated polyethylene (CSM) was so interesting due to binding of the good oil resistance of CSM, the good mechanical properties and low cost of NR. However, due to the different polarities of two rubbers, phase separation and inferior properties of NR/CSM blend were obtained. The practical way to improve its properties is the addition of the third component to bind both phases of the blend. Effects of poly(vinyl chloride), PVC as compatibilizer on cure characteristics, morphology, mechanical properties and automotive fuel resistance of NR/ CSM blend were investigated. In this contribution, NR/CSM blend with blend ratio of 50/50 was prepared using a two-roll mill, and then vulcanized in a compression mold at 160°C. The PVC content was varied from 1 to 7 phr. It was found that the usage of 7 phr PVC led to improve interaction between NR and CSM phases. Therefore, increase in cure characteristics, mechanical strength and automotive fuel resistance of the blend was observed.

STUDY ON THE PROPERTIES OF BLEND OF NATURAL RUBBER LATEX/METHYL METHACRYLATE GRAFTED RUBBER LATEX BY GAMMA RADIATION

Natural rubber latex （NRL） and methyl methacrylate （MMA） grafted rubber latex were blended in different ratios and irradiated at various absorbed doses by gamma rays from Co-60 source at room temperature. The tensile properties, swelling ratio and permanent set were measured. The maximum tensile strength and modulus at 500% elongation were obtained at an absorbed dose of 8 kGy. Modulus increases from 6.99 MPa to 9.87 MPa for an increase in proportion of MMA grafted rubber from 40% to 60% in the blend at similar absorbed dose. Elongation at break and swelling ratio decrease with increasing absorbed dose as well as the MMA grafted rubber content in the blends. The decreasing trend of permanent set is high up to 5 kGy absorbed dose, and beyond that dose, it becomes almost flat.

Mechanical properties of wood flour/recycled-thermoplastic-blends composites

The mechanical properties of composites prepared from wood flour and thermoplastic blends were investigated. Thermoplastic mixtures of polypropylene (PP) and high-density polyethylene (HDPE) and polystyrene (PS), virgin or recycled, were mixed with wood flour in a high speed blender and then extruded by a specially designed twin/single screw extruder system to form wood-flour/thermoplastic-blends composites (WTBCs). Comparative studies were made to evaluate the effectiveness of the two modification methods of the thermoplastic blends, the one of the addition of maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer (SEBS-g-MAH) as compatibilizer and the other of blend grafting of maleic anhydride (MAH) using dicumyl peroxide (DCP) as initiator by reactive extrusion. The results showed that the impact properties of WTBCs using SEBS-g-MAH as compatilizer were better improved than that of the blend grafting. However, adverse results were observed on the tensile and flexural properties of the corresponding WTBCs. The mechanical properties of WTBCs prepared from recycled plastic blends were poorer to some extent than that from virgin plastic blends in general, especially in elongation break. The morphology of WTBCs breaking section was analyzed by scanning electron microscopy (SEM) and the results showed that a good interfacial adhesion between wood flour and polymer matrix was observed with both of the two modification methods. However, by blend grafting of adding DCP as initiator and MAH as monomer, a better interfacial bonding between wood and plastic matrix was obtained than that of the addition of SEBS-g-MAH. Blend grafting can be considered as a potential way of increasing the interfacial compatibility of different plastics and between plastic blends and wood.

EFFECT OF PLASTICIZER ON THE MICROSTRUCTURE OF PS/PVC BLENDS

In this work, controlling of the particle size of PVC in PS/PVC blends was studied. It is shown that viscosity ratio and particle size can be changed by adding a third composition, such as plasticizers, and the distribution of the third composition in two phases plays a very important role in controlling viscosity ratio and particle size. When DOP was used as the plasticizer of PVC in PS/PVC blends, the particle size of PVC could not be reduced due to the transference of DOP into PS phase. When polycaprolactone (PCL) was used as the plasticizer of PVC in the same blends, the particle size of PVC could be descreased obviously because PCL does not migrate to PS phase.

Rheological Studies on Glycerol Plasticized Gelatin and Its Blends with Epoxidized Soybean Oil

Blends of gelatin(Ge)plasticized with varying amounts of glycerol(Gly),buffer solution pH 10 and epoxidized soybean oil(ESO)to enhance hydrophobicity were prepared by mixing and injection-molding.Blends were characterized by rheological tests and microscopy to select optimal conditions for scaling up their processing.The effect of each component on rheological response was analyzed using parallel plate geometry.Coating of gelatin specimens with PDMS during rheological tests led to reliable and reproducible results since water evaporation was prevented.A gradual increment in ESO concentration led to blends with increased degree of phase separation,as evidenced by optical and confocal microscopy.Limited compatibility between ESO and Ge increased viscosity at high ESO levels,but up to 10%Gly could be replaced with ESO without a significant variation of rheological behavior.

CHARACTERISTICS OF CATION—CONDUCTIVE BLENDS PLASTICIZED WITH PROPYLENE CARBONATE

The cation—conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single—cation conduction over a wide range of plasticizer composition. The plasticizer not only increases the conductivity of the blends but also decreases the electrochemical interface resistance between the blend and lithium electrode. The carrier in the blends obviously grows in number.

Improved Automotive Fuel Resistance of Natural Rubber/Chlorosulfonated Polyethylene Blends by Blending Epoxidized Natural Polymer

The natural rubber (NR) was mixed with chlorosulfonated polyethylene (CSM), due to the difference of polarity in NR and CSM made this blend incompatible and the third component was used. Epoxidzed natural rubber (ENR) was used as a third component. NR/CSM blended with the blend ratio of 50/50 was prepared by using a two-roll mill and vulcanization in a compression mold at 160°C. The ENR content was varied from 1 to 7 phr. The curing characteristics, morphology, mechanical properties, and automotive fuel swelling were investigated. The results indicated that the cure time of the blend rubbers was shorter as adding ENR. The mechanical properties of the blend rubbers were not affected by ENR content. However, automotive fuel resistance of the blend rubbers was found to increase with adding ENR in rubber blend.

Natural Rubber/Fluoro Elastomer Blends: Effect of Third Component on Cure Characteristics, Morphology,Mechanical Properties, and Automotive Fuel Swelling

The natural rubber (NR) was mixed with fluoro elastomer (FKM), due to the difference of polarity in NR and FKM made this blend incompatible so the third component was used. NR/FKM blended with the blend ratio of 70/30 was prepared by using a two-roll mill and vulcanization in a compression mold at 180℃ using peroxide as a curative agent. Epoxidized natural rubber (ENR) or polyisoprene-graft-maleic acid monomethyl ester (PI-ME) was used as a third component. The curing characteristics, morphology, mechanical properties, and automotive fuel swelling were investigated. The results indicated that the scorch time and cure time of the blend rubbers were longer as adding ENR or PI-ME. Both mechanical properties and automotive fuel resistance of the blend rubbers were found to increase with adding ENR in rubber blend. Conversely for adding PI-ME, automotive fuel resistance of the blend rubbers was found to decrease progressively with increasing PI-ME content.

Shandong Gaomi Mida Rubber & Plastic Products Co., Ltd.

Shandong Gaomi Mida Rubber & Plastic Products Co., Ltd. (est. 1992) is a new high-technology enterprise that produces various kinds of parts for both washing machines and automobiles.

Study on combustion kinetics of the blend melt with coal and waste plastic

The combustiondynamic experiments of blend-melt samples of blending pulverized coal and waste plastic are carried out in different proportions at different combustion temperatures.The experiment shows that all of correlation coefficients for fitting straight lines of curve F(a)-1/T of the blend-melt samples are above 0.95,which indicates that the combustion of samples conforms to the rules of first order reaction.The experiment also shows that the activation energy is the lowest and the combustion becomes easier with the mix proportion of 20%-25% at 200 ℃.

Development of Biobased Poly(Lactic Acid)/Epoxidized Natural Rubber Blends Processed by Electrospinning: Morphological, Structural and Thermal Properties

This article reports the production of electrospun fibers from blends of poly(lactic acid) (PLA) and epoxidized natural rubber (ENR) solutions. The produced fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). SEM images showed the reduction in fiber size with ENR content of up to 25% in the mixture PLA/ENR. FTIR analysis revealed a possible interaction between carboxylic group of PLA and epoxi group of ENR. Thermal analysis showed the increase of the crystallinity fraction with ENR content and a decrease in thermal stability of eletrospun mats with the addition of ENR. The dynamic mechanical properties showed an enhancement of the stiffness of PLA/ENR blends with the increase of ENR content, which can support the production of interesting materials for tissue engineering based on renewable and biocompatible polymers. The reported properties indicate the possibility to use such fiber mats as potential materials in tissue engineering.

Fate of rubber bush (Calotropis procera (Aiton) W. T. Aiton) in adversary environment modulated by microstructural and functional attributes

Calotropis procera(Aiton)W.T.Aiton,belonging to the family Apocynaceae,is C3 evergreen plant species in arid and semi-arid areas of the Punjab Province,Pakistan.It grows in a variety of habitats like salt affected and waterlogged area,desert/semi-desert,roadside,wasteland,graveyard,forest,crop field,coastline,and river/canal bank.A total of 12 populations growing in different ecological regions were sampled to evaluate their growth,physio-biochemical,and anatomical responses to specific environmental condition.Population adapted to desert/semi-desert showed vigorous growth(plant height,shoot length,and number of leaves),enhanced photosynthetic level(chlorophyll a,chlorophyll b,carotenoids,and total chlorophyll),and apparent anatomical modifications such as increased stem radius,cuticle thickness,storage parenchyma tissues(cortex and pith),and vascular bundles in stems,while the maximum of midrib and lamina thickness,epidermal cells,cuticle thickness,cortical proportion,abaxial stomatal density,and its area in leaves.There was high plasticity in structural and functional features of these populations,which enable them to survive and tolerate under such hot and dry desert environment.Population of saline areas exhibited very critical modifications to sustain under salt prone environment.At physiological level,it possesses the maximum amount of organic osmolytes(glycine betaine and proline)and antioxidants(superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)),while at anatomical level,it showed intensive sclerification,large phloem region(inner and outer),pith parenchyma cells,and metaxylem vessels in stems and leaves.The population of dry mountains showed very distinctive features,such as increased shoot ionic contents(K+and Ca2+),collenchyma and sclerenchyma thickness in stems,trichomes size,and numerous small stomata on abaxial surface of leaves.It is concluded that no definite or precise single character can be taken as a yardstick for adjudging the biomass production in this rubber bush weed population.

基于病例引导的“互联网+”混合式教学在整形外科教学中的应用

目的:为了适应当前医学教育的发展趋势,将基于病例引导的“互联网+”模式下混合式教学应用到整形外科教学中并探讨其效果。方法:选取2018年6月-2022年1月于新疆医科大学第一附属医院整形科规范化培训及进修的56名学员,根据接受的教学方式不同分为传统模式教学组和混合式模式教学组,各28名。分别接受两种不同的教学方式并进行理论授课及临床实践教学,通过分析两组学员出科考核成绩及教学满意度,进一步判断整形外科相关知识掌握情况、评估教学效果。结果:教学结束后,混合式模式教学组专业知识笔试及技能操作成绩均显著优于传统教学组(P<0.05);混合式模式教学组满意度评分显著高于传统教学组(P<0.05)。结论:基于病例引导的“互联网+”模式下混合式教学较传统教学优势明显,有助于提升教学质量、提高学员满意度、激发学习兴趣。

液体丁腈橡胶YN25对丁腈橡胶2980的改性

将液体丁腈橡胶(牌号YN 25)与丁腈橡胶(NBR)2980进行机械共混制备了NBR 2980 M,研究了YN 25加入量对NBR 2980 M混炼胶的门尼黏度、硬度和硫化特性及硫化胶拉伸性能的影响。结果表明,随YN 25加入量增加,NBR 2980 M的门尼黏度、50 min的300%定伸应力、拉伸强度、最大和最小转矩均呈线性下降,扯断伸长率及25 min、50 min和90 min三个转矩差硫化时间均线性上升,而混炼胶硬度的变化不明显。YN 25在NBR 2980 M中的质量分数每增加1%,混炼胶门尼黏度下降0.78,50 min的300%定伸应力、拉伸强度、最大和最小转矩分别下降0.15 MPa、0.17 MPa、0.12 dN·m和0.02 dN·m,扯断伸长率及25 min、50 min和90 min三个硫化时间分别增加4.1%、0.05 min、0.08 min和0.18 min。