Silicone rubber/polyacrylate sequential interpenetrating polymer networks(IPNs) were prepared by silicone rubber sheet dipped into the solution composed of different acrylate monomers and benzoyl peroxides(BPOs) for d...Silicone rubber/polyacrylate sequential interpenetrating polymer networks(IPNs) were prepared by silicone rubber sheet dipped into the solution composed of different acrylate monomers and benzoyl peroxides(BPOs) for different time at room temperature and then acrylate polymerized at 80℃for 2 h. The molecular structure and damping properties of sequential IPNs were studied by means of FT-IR and dynamic mechanical analysis(DMA), respectively. The FT-IR spectrum shows that polyacrylate distributes unevenly along the thickness direction of IPNs, i.e. the concentration of polyacrylate decreases from the midst to the surface of the IPNs. The DMA shows that cold crystallization of silicone in the temperature range from -47℃to -30℃is reduced and loss factor of IPNs is improved after interpenetrating with polyacrylate. This suggestes that IPNs can be used as damping materials.展开更多
Interpenetrating polymer networks （IPNs） based on fluoroelastomer/butadiene-acrylonitrile rubber （FKM/NBR） by molten blending at a high temperature and chemical cross-linking of two components were prepared. The i...Interpenetrating polymer networks （IPNs） based on fluoroelastomer/butadiene-acrylonitrile rubber （FKM/NBR） by molten blending at a high temperature and chemical cross-linking of two components were prepared. The influence of the two networks component on the mechanical properties and thermostabilities was studied. The experimental results show that the mechanical properties of the IPNs are superior to those of the individual FKM and NBR networks due to forming the case of interpenetrating and intercross-linking between the two networks, the mechanical properties and thermal resistance exhibit higher values when 80/20 （w/w） FKM and NBR is blended and respectively cured simultaneously. The co-continuous morphology of the IPNs in the blends of 80/20 （w/w） FKM/NBR is found by transmission electron microscopy （TEM）, the differential scanning calorimetry （DSC） determination shows that the blends of 80/20 （w/w） FKM/NBR have better compatibility, and the glass transition temperature of the elastomer is -21.5 ℃.展开更多
The non-Gaussian three-chain, eight-chain and full network models for rubber elasticity are cast in rate from. For computational converlency, incompressibility is incorporated through a penalty-type approach. The effi...The non-Gaussian three-chain, eight-chain and full network models for rubber elasticity are cast in rate from. For computational converlency, incompressibility is incorporated through a penalty-type approach. The efficiency and accuracy of the rate forms are discussed in detail.展开更多
The heterogeneous free-radical polymerization of methyl methylacrylate (MMA) and divinylbenzene (DVB) as cross-linker within supercritical carbon dioxide-swollen silicon rubber (SR) has been studied as an approach to ...The heterogeneous free-radical polymerization of methyl methylacrylate (MMA) and divinylbenzene (DVB) as cross-linker within supercritical carbon dioxide-swollen silicon rubber (SR) has been studied as an approach to preparing semi-interpenetrating polymer network (semi-IPN) of SR and poly(methyl methylacrylate) (PMMA). The SR/PMMA semi-IPNs were characterized by scanning electron microscopy (SEM) and dynamic mechanical analyzer (DMA).展开更多
Large strain fixed-end torsion of circular solid rubber bars is studied semi-analytically. The analyses are based on various non-Gaussian network models for rubber elasticity, some of which were proposed very recently...Large strain fixed-end torsion of circular solid rubber bars is studied semi-analytically. The analyses are based on various non-Gaussian network models for rubber elasticity, some of which were proposed very recently. Results are presented in terms of predicted torque vs. twist curves and axial force vs. twist curves. In some cases, the predicted stress distributions are also given. The sensitivity of the second-order axial force to the employed models is considered. The predicted results are compared with experimental results found in the literature.展开更多
By incorporating copper sulfate （CuSO4） particles into acrylonitrile butadiene rubber （NBR） followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination cros...By incorporating copper sulfate （CuSO4） particles into acrylonitrile butadiene rubber （NBR） followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination crosslinking. This method totally differs from traditional covalent or non-covalent vulcanization approaches of rubber. No other vulcanizing agent or additional additive is involved in this process. By analyzing the results of DMA, XPS and FT-IR, it is found that the crosslinking of CuSO4 particles filled NBR was induced by in situ coordination between nitrogen atoms of nitrile groups （-CN） and copper ions （Cu^2＋） from CuSO4. SEM and EDX results revealed the generation of a core （CuSO4 solid particle）- shell （adherent NBR） structure, which leads to a result that the crosslinked rubber has excellent mechanical properties. Moreover, poly（vinyl chloride） （PVC） and liquid acrylonitrile-butadiene rubber （LNBR） were used as mobilizer to improve the coordination crosslinking of CuSO4/NBR. The addition of PVC or LNBR could lead to higher crosslink density and better mechanical properties of coordination vulcanization. In addition, crystal water in CuSO4 played a positive role to coordination crosslinking of rubber because it decreased the metal point of CuSO4 and promoted the metal ionization.展开更多
基金Project (50473013) supported by the National Natural Science Foundation of China
文摘Silicone rubber/polyacrylate sequential interpenetrating polymer networks(IPNs) were prepared by silicone rubber sheet dipped into the solution composed of different acrylate monomers and benzoyl peroxides(BPOs) for different time at room temperature and then acrylate polymerized at 80℃for 2 h. The molecular structure and damping properties of sequential IPNs were studied by means of FT-IR and dynamic mechanical analysis(DMA), respectively. The FT-IR spectrum shows that polyacrylate distributes unevenly along the thickness direction of IPNs, i.e. the concentration of polyacrylate decreases from the midst to the surface of the IPNs. The DMA shows that cold crystallization of silicone in the temperature range from -47℃to -30℃is reduced and loss factor of IPNs is improved after interpenetrating with polyacrylate. This suggestes that IPNs can be used as damping materials.
文摘Interpenetrating polymer networks （IPNs） based on fluoroelastomer/butadiene-acrylonitrile rubber （FKM/NBR） by molten blending at a high temperature and chemical cross-linking of two components were prepared. The influence of the two networks component on the mechanical properties and thermostabilities was studied. The experimental results show that the mechanical properties of the IPNs are superior to those of the individual FKM and NBR networks due to forming the case of interpenetrating and intercross-linking between the two networks, the mechanical properties and thermal resistance exhibit higher values when 80/20 （w/w） FKM and NBR is blended and respectively cured simultaneously. The co-continuous morphology of the IPNs in the blends of 80/20 （w/w） FKM/NBR is found by transmission electron microscopy （TEM）, the differential scanning calorimetry （DSC） determination shows that the blends of 80/20 （w/w） FKM/NBR have better compatibility, and the glass transition temperature of the elastomer is -21.5 ℃.
文摘The non-Gaussian three-chain, eight-chain and full network models for rubber elasticity are cast in rate from. For computational converlency, incompressibility is incorporated through a penalty-type approach. The efficiency and accuracy of the rate forms are discussed in detail.
基金This work was supported by the National Natural Science Foundation of China (50173030).
文摘The heterogeneous free-radical polymerization of methyl methylacrylate (MMA) and divinylbenzene (DVB) as cross-linker within supercritical carbon dioxide-swollen silicon rubber (SR) has been studied as an approach to preparing semi-interpenetrating polymer network (semi-IPN) of SR and poly(methyl methylacrylate) (PMMA). The SR/PMMA semi-IPNs were characterized by scanning electron microscopy (SEM) and dynamic mechanical analyzer (DMA).
文摘Large strain fixed-end torsion of circular solid rubber bars is studied semi-analytically. The analyses are based on various non-Gaussian network models for rubber elasticity, some of which were proposed very recently. Results are presented in terms of predicted torque vs. twist curves and axial force vs. twist curves. In some cases, the predicted stress distributions are also given. The sensitivity of the second-order axial force to the employed models is considered. The predicted results are compared with experimental results found in the literature.
基金This work was financially supported by the Program of National Natural Science Foundation of China(No.50473031).
文摘By incorporating copper sulfate （CuSO4） particles into acrylonitrile butadiene rubber （NBR） followed by heat pressing, a novel vulcanization method is developed in rubber through the formation of coordination crosslinking. This method totally differs from traditional covalent or non-covalent vulcanization approaches of rubber. No other vulcanizing agent or additional additive is involved in this process. By analyzing the results of DMA, XPS and FT-IR, it is found that the crosslinking of CuSO4 particles filled NBR was induced by in situ coordination between nitrogen atoms of nitrile groups （-CN） and copper ions （Cu^2＋） from CuSO4. SEM and EDX results revealed the generation of a core （CuSO4 solid particle）- shell （adherent NBR） structure, which leads to a result that the crosslinked rubber has excellent mechanical properties. Moreover, poly（vinyl chloride） （PVC） and liquid acrylonitrile-butadiene rubber （LNBR） were used as mobilizer to improve the coordination crosslinking of CuSO4/NBR. The addition of PVC or LNBR could lead to higher crosslink density and better mechanical properties of coordination vulcanization. In addition, crystal water in CuSO4 played a positive role to coordination crosslinking of rubber because it decreased the metal point of CuSO4 and promoted the metal ionization.
