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 distri...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.展开更多
The dynamic mechanical modulus at 25℃ for blends of segmented polyurethanes with PVC was studied by using suitable mechanics models of multi-component systems. The analysis indicates that the blend morphology was mai...The dynamic mechanical modulus at 25℃ for blends of segmented polyurethanes with PVC was studied by using suitable mechanics models of multi-component systems. The analysis indicates that the blend morphology was mainly determined by soft segment structure of polyurethanes. The PPO-PU/PVC blends show typical two-phase morphology and their modulus-composition relations may be described by Halpin-Tsai model for domain-matrix two-phase systems.While the PCL-PU / PVC, PTMA-PU/PVC and PTMO-PU/PVC blends fit the Kerner's packed grain composite model. These results may imply that the modulus-composition relationship is sensitive to the interactions between the components and the mixture morphology of the blends.展开更多
Film specimens of four segmented polyurethanes with different soft segments, namely polycaprolactone, polytetramethylene adipate, polytetramethylene oxide and polypropylene oxide, and their blends with PVC of differen...Film specimens of four segmented polyurethanes with different soft segments, namely polycaprolactone, polytetramethylene adipate, polytetramethylene oxide and polypropylene oxide, and their blends with PVC of different compositions were obtained by solution cast. The permeability of these films to O_2, N_2 and H_2 and their density were measured by using gas chromatography and technique of density gradient column. The polyether polyurethanes were found to have higher permeability than the polyester ones due to their low glass transition temperature and /or the low density value. The blends of PVC and polyether polyurethanes, especially the PPO-based polyurethane, are incompatible, and their permeability coefficient-composition dependence has the typical S-shaped curves. PVC is well compatible with the soft segments in its blends with polyester polyurethanes. For these blends the composition dependence of permeability is characterized by a negative deviation from the semilogarithmic additivity rule, and it is possible to prepare blends having T_g 20℃ lower than that of PVC, but retaining its low permeability almost unchanged, results were discussed in according with the different approaches for the permeation behavior of compatible and incompatible blends.展开更多
Series of PVC/ABS and PVC/SBS blends of composition 20/ 80. 40/ 60, 60 / 40 and 80 / 20were prepared in a screw extruder. The phase morphology, miscibility and rheological behaviour of two systems were investigated. T...Series of PVC/ABS and PVC/SBS blends of composition 20/ 80. 40/ 60, 60 / 40 and 80 / 20were prepared in a screw extruder. The phase morphology, miscibility and rheological behaviour of two systems were investigated. The viscosity-composition plots were represented by sub-cluster equation, the various differences between two systems are interpreted with the equation parameters展开更多
The mechanical and thermal properties of solution-cast blends of Polyvinyl chloride (PVC) and Epoxidized Liquid Natural Rubber having 30 mole % epoxidation (ELNR-30) have been examined using Zwick materials testing ma...The mechanical and thermal properties of solution-cast blends of Polyvinyl chloride (PVC) and Epoxidized Liquid Natural Rubber having 30 mole % epoxidation (ELNR-30) have been examined using Zwick materials testing machine and heating in air circulating oven (200°C) at different time intervals respectively. The ELNR was prepared by oxidative degradation of natural rubber latex using Phenylhydrazine/Oxygen system and subsequent epoxidation with formic acid and 30% H2O2. Tensile strength of unblended PVC was 26.5 ± 0.5 MPa. The blends had lower tensile strength which decreased with increase in blend ratio of ELNR-30. Experimental data revealed that there was greater homogeneity in the PVC/ELNR-30 (80/20) compared with PVC/ELNR-30 (90/10). The PVC/ELNR-30 (80/20) also showed superior elongation at maximum (%) than the unblended PVC and PVC/ELNR-30 (90/10) in that order. Thermal stability decreased in the order PVC, PVC/ELNR-30 (90/10), PVC/ELNR-30 (80/20).展开更多
The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficien...The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficient biomechanical properties,blended films composed of silk fibroin( SF) and poly( ε-caprolactone)( PCL) were fabricated by electrospinning in this study. Scanning electron microscope( SEM), X-ray diffraction( XRD),thermal analysis,Fourier transform-infrared( FT-IR),Raman spectra,mechanical testing,and water solubility were used to characterize the morphological, structural and mechanical properties of the blended electrospinning films. Results showed that the diameter of the blended fiber was distributed between 600 and1000 nm,and the fiber diameter increased as the PCL content increased. There is no obvious phase separation due to the similarity and intermiscibility,as well as the interactions( mainly hydrogen bonds), between the two polymers. Meanwhile, the secondary structures of SF changed from random coils and Silk I to Silk II because of the interactions between SF and PCL. For this reason,the tensile strength and elongation at break of the electrospinning films improved significantly,and the water solubility decreased. In conclusion,the blended electrospinning films fabricated in this study showed satisfying mechanical properties and water insolubilities,and they may be promising biomaterials for applications in tissue engineering for blood vessels,nerve conduits,tendons,ligaments and other tissues.展开更多
In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (APC) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction par...In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (APC) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction parameter between the polymers is calculated from the melting point depression data. Using optical microscope, the shapes of the PCL spherulites in the blends are observed.展开更多
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 differen...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.展开更多
文摘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.
文摘The dynamic mechanical modulus at 25℃ for blends of segmented polyurethanes with PVC was studied by using suitable mechanics models of multi-component systems. The analysis indicates that the blend morphology was mainly determined by soft segment structure of polyurethanes. The PPO-PU/PVC blends show typical two-phase morphology and their modulus-composition relations may be described by Halpin-Tsai model for domain-matrix two-phase systems.While the PCL-PU / PVC, PTMA-PU/PVC and PTMO-PU/PVC blends fit the Kerner's packed grain composite model. These results may imply that the modulus-composition relationship is sensitive to the interactions between the components and the mixture morphology of the blends.
文摘Film specimens of four segmented polyurethanes with different soft segments, namely polycaprolactone, polytetramethylene adipate, polytetramethylene oxide and polypropylene oxide, and their blends with PVC of different compositions were obtained by solution cast. The permeability of these films to O_2, N_2 and H_2 and their density were measured by using gas chromatography and technique of density gradient column. The polyether polyurethanes were found to have higher permeability than the polyester ones due to their low glass transition temperature and /or the low density value. The blends of PVC and polyether polyurethanes, especially the PPO-based polyurethane, are incompatible, and their permeability coefficient-composition dependence has the typical S-shaped curves. PVC is well compatible with the soft segments in its blends with polyester polyurethanes. For these blends the composition dependence of permeability is characterized by a negative deviation from the semilogarithmic additivity rule, and it is possible to prepare blends having T_g 20℃ lower than that of PVC, but retaining its low permeability almost unchanged, results were discussed in according with the different approaches for the permeation behavior of compatible and incompatible blends.
文摘Series of PVC/ABS and PVC/SBS blends of composition 20/ 80. 40/ 60, 60 / 40 and 80 / 20were prepared in a screw extruder. The phase morphology, miscibility and rheological behaviour of two systems were investigated. The viscosity-composition plots were represented by sub-cluster equation, the various differences between two systems are interpreted with the equation parameters
文摘The mechanical and thermal properties of solution-cast blends of Polyvinyl chloride (PVC) and Epoxidized Liquid Natural Rubber having 30 mole % epoxidation (ELNR-30) have been examined using Zwick materials testing machine and heating in air circulating oven (200°C) at different time intervals respectively. The ELNR was prepared by oxidative degradation of natural rubber latex using Phenylhydrazine/Oxygen system and subsequent epoxidation with formic acid and 30% H2O2. Tensile strength of unblended PVC was 26.5 ± 0.5 MPa. The blends had lower tensile strength which decreased with increase in blend ratio of ELNR-30. Experimental data revealed that there was greater homogeneity in the PVC/ELNR-30 (80/20) compared with PVC/ELNR-30 (90/10). The PVC/ELNR-30 (80/20) also showed superior elongation at maximum (%) than the unblended PVC and PVC/ELNR-30 (90/10) in that order. Thermal stability decreased in the order PVC, PVC/ELNR-30 (90/10), PVC/ELNR-30 (80/20).
基金National Natural Science Foundations of China(No.30970714,No.51103092)Natural Science Foundation of Jiangsu Province,China(No.BK2012634)+1 种基金College Natural Science Research Project of Jiangsu Province,China(No.12KJA430003)Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficient biomechanical properties,blended films composed of silk fibroin( SF) and poly( ε-caprolactone)( PCL) were fabricated by electrospinning in this study. Scanning electron microscope( SEM), X-ray diffraction( XRD),thermal analysis,Fourier transform-infrared( FT-IR),Raman spectra,mechanical testing,and water solubility were used to characterize the morphological, structural and mechanical properties of the blended electrospinning films. Results showed that the diameter of the blended fiber was distributed between 600 and1000 nm,and the fiber diameter increased as the PCL content increased. There is no obvious phase separation due to the similarity and intermiscibility,as well as the interactions( mainly hydrogen bonds), between the two polymers. Meanwhile, the secondary structures of SF changed from random coils and Silk I to Silk II because of the interactions between SF and PCL. For this reason,the tensile strength and elongation at break of the electrospinning films improved significantly,and the water solubility decreased. In conclusion,the blended electrospinning films fabricated in this study showed satisfying mechanical properties and water insolubilities,and they may be promising biomaterials for applications in tissue engineering for blood vessels,nerve conduits,tendons,ligaments and other tissues.
基金The subject supported by National Natural Science Foundation of China
文摘In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (APC) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction parameter between the polymers is calculated from the melting point depression data. Using optical microscope, the shapes of the PCL spherulites in the blends are observed.
文摘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.
