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 most common way of rubbers for obtaining high performance is vulcanization, by which the linear macromolecules are crosslinked into three-dimensional networks. The rubbers vulcanized by covalent bonds are serious ...The most common way of rubbers for obtaining high performance is vulcanization, by which the linear macromolecules are crosslinked into three-dimensional networks. The rubbers vulcanized by covalent bonds are serious pollutants. There has been an increasing interest in the novel rubbers crosslinked by supramolecular interactions such as hydrogen bonds and ionic bonds because of the supramolecular interactions are reversible and the crosslinked materials are likely to be recycled. In this paper, a series of novel NBR/PVC materials crosslinked with CuSO4 by coordinate bonds were prepared for the first time, and the produced materials have excellent mechanical properties. In this system, the coordinate bonds formed in situ during the heat press process. XPS and SEM results prove that there are really crosslinks by coordinated bonds between the polymers and the CuSO4 particles. The characterizations of mechanical properties, crosslink densities and the temperature of glass transition all showed that degree of crosslink and the performance of the coordinated materials could be adjusted controllably.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).
文摘The most common way of rubbers for obtaining high performance is vulcanization, by which the linear macromolecules are crosslinked into three-dimensional networks. The rubbers vulcanized by covalent bonds are serious pollutants. There has been an increasing interest in the novel rubbers crosslinked by supramolecular interactions such as hydrogen bonds and ionic bonds because of the supramolecular interactions are reversible and the crosslinked materials are likely to be recycled. In this paper, a series of novel NBR/PVC materials crosslinked with CuSO4 by coordinate bonds were prepared for the first time, and the produced materials have excellent mechanical properties. In this system, the coordinate bonds formed in situ during the heat press process. XPS and SEM results prove that there are really crosslinks by coordinated bonds between the polymers and the CuSO4 particles. The characterizations of mechanical properties, crosslink densities and the temperature of glass transition all showed that degree of crosslink and the performance of the coordinated materials could be adjusted controllably.
