In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to thei...In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.展开更多
Growing demand for high-performance materials is driving the development of composites with nano material reinforcement. The use of nano reinforcement can provide a distinct advantage due to high surface area of the m...Growing demand for high-performance materials is driving the development of composites with nano material reinforcement. The use of nano reinforcement can provide a distinct advantage due to high surface area of the material. There are still many challenges in achieving the full potential of nanocomposites. In this paper, we investigate the performance of epoxy nanocomposites reinforced with short polymethyl methacrylate (PMMA) nanofibers. PMMA nanofibers were chopped and mixed with the epoxy resin and then the mixture was poured into a mould. Samples were cut to an appropriate size after cure and mechanical testing was carried out. Tensile and flexural strength and modulus were evaluated for samples with various fiber volume fractions to determine changes in mechanical performance. Also Scanning Electron Microscopy was utilized to investigate fracture surface and fiber-matrix interface. Results indicated that mechanical performance dropped as volume fraction of fibers increased, namely poor fiber-matrix adhesion and presence of porosity resulted in deterioration in strength and modulus. Further research is required to develop fiber coating system to enhance performance of the nanocomposite by improving fiber-matrix adhesion and fiber wet-out.展开更多
The functional groups on graphene sheets surface affect their dispersion and interfacial adhesion in polymer matrix. We compared the mechanical property of polymethymethacrylate（PMMA） microcellular foams reinforced ...The functional groups on graphene sheets surface affect their dispersion and interfacial adhesion in polymer matrix. We compared the mechanical property of polymethymethacrylate（PMMA） microcellular foams reinforced with graphene oxide（GO） and reduced graphene oxide（RGO） to investigate this influence of functional groups. RGO sheets were fabricated by solvent thermal reduction in DMF medium. UV-Vis, FT-IR and XPS analyses indicate the difference of oxygen-containing groups on GO and RGO sheets surface. The observation of SEM illustrates that the addition of a smaller number of GO or RGO sheets causes a fine cellular structure of PMMA foams with a higher cell density(about 1011 cells/cm3) and smaller cell sizes（about 1-2 μm） owing to their remarkable heterogeneous nucleation effect. Compared to GO reinforced foams, the RGO/PMMA foams own lower cell density and bigger cell size in their microstructure, and their compressive strength is lower even when the reinforcement contents are the same and the foam bulk density is higher. These results indicate that the oxygen-containing groups on GO sheets’ surface are beneficial to adhere CO2 to realize a larger nucleation rate, and their strong interaction with PMMA matrix improves the mechanical property of PMMA foams.展开更多
The paper was aimed at the PMMA/HNTs composite nanofibers with well enhanced mechanical properties prepared by electrospinning technique for the first time. A series of characterizations were used to illustrate the st...The paper was aimed at the PMMA/HNTs composite nanofibers with well enhanced mechanical properties prepared by electrospinning technique for the first time. A series of characterizations were used to illustrate the structure and properties of the composite nanofibers by SEM, XRD, FTIR and DSC techniques. The effect of the PMMA/HNTs composite nanofibers in relationship to the mass percentage of HNTs was investigated. The results indicated that HNTs wrapped in polymer matrix were highly oriented and dispersed by the electrospinning technique, resulting in improved thermal stability of the polymer. Moreover, the mechanical properties of the PMMA/HNTs composite nanofibers which were dependent on HNTs mass content were measured, and good enhanced mechanical properties were obtained.展开更多
The polymethyl-methacrylate (PMMA)-based composites were prepared using goose feather fibers at different diameters. The fibers, which were washed and dried, cut through the shaft, and their sizes were shrunk to short...The polymethyl-methacrylate (PMMA)-based composites were prepared using goose feather fibers at different diameters. The fibers, which were washed and dried, cut through the shaft, and their sizes were shrunk to short fiber form. Then the obtained short fibers were added into acryl matrix in portions of 2%, 4%, 6%, and 8% in volume. The mixture containing goose feather fiber was shaped via free casting method, and the goose feather fiber/PMMA composites were obtained. The samples, which were processed in accordance with the standards of test to be implemented after the thermal curing process, were characterized in terms of the mechanical properties after being evaluated by using three-point flexure test and impact test. For the goose feather-added composites, a significant increase was observed in rupture resistance, flexural strength, and flexure module. The flexure test curves of composites clearly revealed the slow and stable crack enlargement. Micro mechanisms of toughening and rupture processes were observed under the light of microstructure of rupture surfaces. The results of present study showed that the goose feather can be used as an important reinforcing material for bio-composites.展开更多
Blending of polymer with organic/inorganic material has given a new direction for developing novel materials. This is an easy and inexpensive method of modifying various properties of the individual materials and comp...Blending of polymer with organic/inorganic material has given a new direction for developing novel materials. This is an easy and inexpensive method of modifying various properties of the individual materials and composites. The aim of the present work is an attempt to incorporate crystals in polymer host and investigate the effect, on optical properties of the of polymer- crystal combine. In this paper a novel technique of incorporating inorganic/organic crystal in a host polymer matrix is reported. Crystals of acetoacetanilide (AA) are grown in the host Poly Methyl Methacrelate (PMMA) by simple evaporation technique. The scanning electron micrograph (SEM) studies reveal the growth of Acetoacetanilide crystals of varying sizes and shapes (flakes) in prepared samples. The results are confirmed by various spectroscopic characterization studies such as X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and the UV-Vis spectroscopy. The investigations carried out, show a change in optical absorption band edge which is attributed due to change in band gap because of crystal sizes.展开更多
Methyl Methacrylate(MMA) has been filled in the apertures of aligned carbon nanotubes(ACNTs). Then PMMA/ACNTs composites have been synthesized by in-situ polymerization. The SEM results show that carbon nanotubes are ...Methyl Methacrylate(MMA) has been filled in the apertures of aligned carbon nanotubes(ACNTs). Then PMMA/ACNTs composites have been synthesized by in-situ polymerization. The SEM results show that carbon nanotubes are well dispersed and directionally arranged in the composites. The electrical conductivities of the parallel direction (parallel with ACNTs) and perpendicular direction (perpendicular with ACNTs) of composites were respectively tested to be 15 S·cm-1 and 4 S·cm-1, so the composites were conductivity anisotropic. Compared with PMMA, the thermal stable temperature of composites in air was improved by 100 ℃,and the thermal con- ductivity of composites was 13.64 times of PMMA.展开更多
文摘In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.
文摘Growing demand for high-performance materials is driving the development of composites with nano material reinforcement. The use of nano reinforcement can provide a distinct advantage due to high surface area of the material. There are still many challenges in achieving the full potential of nanocomposites. In this paper, we investigate the performance of epoxy nanocomposites reinforced with short polymethyl methacrylate (PMMA) nanofibers. PMMA nanofibers were chopped and mixed with the epoxy resin and then the mixture was poured into a mould. Samples were cut to an appropriate size after cure and mechanical testing was carried out. Tensile and flexural strength and modulus were evaluated for samples with various fiber volume fractions to determine changes in mechanical performance. Also Scanning Electron Microscopy was utilized to investigate fracture surface and fiber-matrix interface. Results indicated that mechanical performance dropped as volume fraction of fibers increased, namely poor fiber-matrix adhesion and presence of porosity resulted in deterioration in strength and modulus. Further research is required to develop fiber coating system to enhance performance of the nanocomposite by improving fiber-matrix adhesion and fiber wet-out.
基金Funded by the National Nature Science Foundation of China(No.51521001)
文摘The functional groups on graphene sheets surface affect their dispersion and interfacial adhesion in polymer matrix. We compared the mechanical property of polymethymethacrylate（PMMA） microcellular foams reinforced with graphene oxide（GO） and reduced graphene oxide（RGO） to investigate this influence of functional groups. RGO sheets were fabricated by solvent thermal reduction in DMF medium. UV-Vis, FT-IR and XPS analyses indicate the difference of oxygen-containing groups on GO and RGO sheets surface. The observation of SEM illustrates that the addition of a smaller number of GO or RGO sheets causes a fine cellular structure of PMMA foams with a higher cell density(about 1011 cells/cm3) and smaller cell sizes（about 1-2 μm） owing to their remarkable heterogeneous nucleation effect. Compared to GO reinforced foams, the RGO/PMMA foams own lower cell density and bigger cell size in their microstructure, and their compressive strength is lower even when the reinforcement contents are the same and the foam bulk density is higher. These results indicate that the oxygen-containing groups on GO sheets’ surface are beneficial to adhere CO2 to realize a larger nucleation rate, and their strong interaction with PMMA matrix improves the mechanical property of PMMA foams.
基金supported by the Talent Introduction Fund of Yangzhou University(2012)the Key Research Project-Industry Foresight and General Key Technology of Yangzhou(YZ2015020)+3 种基金the Innovative Talent for the Green Yangzhou Golden Phoenix Program(yzlyjfjh2015CX073)the Jiangsu Province Science and Technology Support Project(BE2014613)the Six Talent Peaks of Jiangsu Province(2014-XCL-013)the Project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The paper was aimed at the PMMA/HNTs composite nanofibers with well enhanced mechanical properties prepared by electrospinning technique for the first time. A series of characterizations were used to illustrate the structure and properties of the composite nanofibers by SEM, XRD, FTIR and DSC techniques. The effect of the PMMA/HNTs composite nanofibers in relationship to the mass percentage of HNTs was investigated. The results indicated that HNTs wrapped in polymer matrix were highly oriented and dispersed by the electrospinning technique, resulting in improved thermal stability of the polymer. Moreover, the mechanical properties of the PMMA/HNTs composite nanofibers which were dependent on HNTs mass content were measured, and good enhanced mechanical properties were obtained.
文摘The polymethyl-methacrylate (PMMA)-based composites were prepared using goose feather fibers at different diameters. The fibers, which were washed and dried, cut through the shaft, and their sizes were shrunk to short fiber form. Then the obtained short fibers were added into acryl matrix in portions of 2%, 4%, 6%, and 8% in volume. The mixture containing goose feather fiber was shaped via free casting method, and the goose feather fiber/PMMA composites were obtained. The samples, which were processed in accordance with the standards of test to be implemented after the thermal curing process, were characterized in terms of the mechanical properties after being evaluated by using three-point flexure test and impact test. For the goose feather-added composites, a significant increase was observed in rupture resistance, flexural strength, and flexure module. The flexure test curves of composites clearly revealed the slow and stable crack enlargement. Micro mechanisms of toughening and rupture processes were observed under the light of microstructure of rupture surfaces. The results of present study showed that the goose feather can be used as an important reinforcing material for bio-composites.
文摘Blending of polymer with organic/inorganic material has given a new direction for developing novel materials. This is an easy and inexpensive method of modifying various properties of the individual materials and composites. The aim of the present work is an attempt to incorporate crystals in polymer host and investigate the effect, on optical properties of the of polymer- crystal combine. In this paper a novel technique of incorporating inorganic/organic crystal in a host polymer matrix is reported. Crystals of acetoacetanilide (AA) are grown in the host Poly Methyl Methacrelate (PMMA) by simple evaporation technique. The scanning electron micrograph (SEM) studies reveal the growth of Acetoacetanilide crystals of varying sizes and shapes (flakes) in prepared samples. The results are confirmed by various spectroscopic characterization studies such as X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR) and the UV-Vis spectroscopy. The investigations carried out, show a change in optical absorption band edge which is attributed due to change in band gap because of crystal sizes.
文摘Methyl Methacrylate(MMA) has been filled in the apertures of aligned carbon nanotubes(ACNTs). Then PMMA/ACNTs composites have been synthesized by in-situ polymerization. The SEM results show that carbon nanotubes are well dispersed and directionally arranged in the composites. The electrical conductivities of the parallel direction (parallel with ACNTs) and perpendicular direction (perpendicular with ACNTs) of composites were respectively tested to be 15 S·cm-1 and 4 S·cm-1, so the composites were conductivity anisotropic. Compared with PMMA, the thermal stable temperature of composites in air was improved by 100 ℃,and the thermal con- ductivity of composites was 13.64 times of PMMA.
