Diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate(TDE-85)/methyl tetrahydrophthalic anhydride (MeTHPA) epoxy resin was modified with polyurethane(PU) and the interpenetrating polymer networks(IPNs) of PU-modified TDE-...Diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate(TDE-85)/methyl tetrahydrophthalic anhydride (MeTHPA) epoxy resin was modified with polyurethane(PU) and the interpenetrating polymer networks(IPNs) of PU-modified TDE-85/MeTHPA resin were prepared. The structural characteristics and properties of PU-modified TDE-85/MeTHPA resin were investigated by Fourier transform infrared(FTIR) spectrum,emission scanning electron microscopy(SEM) and thermogravimetry(TG). The results indicate that epoxy polymer network (Ⅰ) and polyurethane polymer network (Ⅱ) of the modified resin can be obtained and the networks (Ⅰ) and (Ⅱ) interpenetrate and tangle highly each other at the phase interface. The micro morphology presents heterogeneous structure. The integrative properties of PU-modified TDE-85/MeTHPA epoxy resin are improved obviously. The PU-modified TDE-85/ MeTHPA resin's tensile strength reaches 69.39 MPa,the impact strength reaches 23.56 kJ/m,the temperature for the system to lose 1% mass (t1%) is 300 ℃,and that for the system to lose 50% mass (t50%) is 378 ℃. Compared with those of TDE-85/MeTHPA resin,the tensile strength,impact strength,t1% and t50% of the PU-modified resin increases by 48%,115%,30 ℃,11 ℃,respectively. The PU-modified TDE-85/MeTHPA resin has the structure characteristics and properties of interpenetrating polymer networks.展开更多
The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coa...The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coating supports a higher saturated water content, Mχ, and helps to facilitate absorption D. The three parameters of stretched exponential function called the William-Watt equation, Eo, τ, and β, are determined to fit the degraded stress relaxation behavior in the water absorption process because this function quantitatively describes the relaxing ability and has been successfully used by a number of researchers. An increasing in the water content is shown to correlate strongly with a decrease in Eo and fl early in the absorption process between Mt/M（χ） = 0 and Mt/Mχ≈ 0.5. The adhesive characteristics of the coatings are correlated with water content, and shown to exhibit higher cohesive failure in coating epoxies under saturated conditions. This suggests that water interferes with the intermolecular bonding between polymer chains which degrades the bulk materials ability to diffuse stress concentrations and reduces its overall strength.展开更多
We present comparative life-cycle assessments of three fiber-reinforced sheet molding compounds （SMCs） using kenaf fiber, glass fiber and soy protein resin. Sheet molding compounds for automotive applications are ty...We present comparative life-cycle assessments of three fiber-reinforced sheet molding compounds （SMCs） using kenaf fiber, glass fiber and soy protein resin. Sheet molding compounds for automotive applications are typically made of unsaturated polyester and glass fibers. Replacing these with kenaf fiber or soy protein offers potential environmental benefits. A soy-based resin, maleated acrylated epoxidized soy oil （MAESO）, was synthesized from refined soybean oil. Kenaf fiber and polyester resins were used to make SMC 1 composites, while SMC2 composites were made from kenaf fiber and a resin blend of 20% MASEO and 80% unsaturated polyester. Both exhibited good physical and mechanical properties, though neither was as strong as glass fiber reinforced polyester SMC. The functional unit was defined as mass to achieve equal stiffness and stability for the manufacture of interior parts for automobiles. The life-cycle assessments were done on SMCI, SMC2 and glass fiber reinforced SMC. The material and energy balances from producing one functional unit of three composites were collected from lab experiments and the literature. Key environmental measures were computed using SimaPro software. Kenaf fiber-reinforced SMC composites （SMC1 and SMC2） performed better than glass fiber-reinforced SMC in every environmental category. The global warming potentials of kenaf fiber-reinforced SMC （SMCI） and kenaf soy resin-based SMC （SMC2） were 45% and 58%, respectively, of glass fiber-reinforced SMC. Thus, we have demonstrated significant ecological benefit from replacing glass fiber reinforced SMC with soy-based resin and natural fiber.展开更多
This paper studies the structure and properties of the polycarbonate polyurethane epoxy resin (PCPU EP) blends being resistant to hydrolysis.The samples were analyzed by an infrared spectrome...This paper studies the structure and properties of the polycarbonate polyurethane epoxy resin (PCPU EP) blends being resistant to hydrolysis.The samples were analyzed by an infrared spectrometer,a differential scanning calorimeter,a scanning electron microscope and a dynamic viscoelastometer.The results show that PCPU EP blends have excellent resistance to hydrolysis and mechanical properties at the ratio of PCPU to EP equal to 10/100 (wt/wt).展开更多
Hydroxyl-epoxy phosphate （HEP） as a reactive corrosion inhibitor was innovatively synthe- sized by the reaction of bisphenol A epoxy resin with phosphoric acid. HEP was mixed with hydroxyl acrylate resin, and crossl...Hydroxyl-epoxy phosphate （HEP） as a reactive corrosion inhibitor was innovatively synthe- sized by the reaction of bisphenol A epoxy resin with phosphoric acid. HEP was mixed with hydroxyl acrylate resin, and crosslinked with waterborne isocyanate curing agent, which was used to form waterborne HEP/acrylic polyurethane composite （HEP-APU） coatings on Q235 steel surfaces. Electrochemical impedance spectroscopy and polarization curves were applied to analyze the corrosion behavior of the HEP-APU coatings in 3.5wt% NaCl solutions. The results indicated that the HEP-APU coatings show a superior passivation property and efficient corrosion protection of Q235 steel. The waterborne acrylic polyurethane coating containing 0.5wt% HEP exhibited the best corrosion performance among all the coating specimens. The improved flash-rust resistance can be attributed to the introduction of the phosphate group which could form phosphate film on the steel substrate.展开更多
A series of Polyurethane (PU)/bisphenol A based Epoxy Resin(EP) Interpenetrating Polymer Networks(IPN) were synthesized and characterized by SEM, DSC, TGA and DMTA. It was found that IPN shows the best compatibility a...A series of Polyurethane (PU)/bisphenol A based Epoxy Resin(EP) Interpenetrating Polymer Networks(IPN) were synthesized and characterized by SEM, DSC, TGA and DMTA. It was found that IPN shows the best compatibility and damping properties when the ratio of PU/EP is 80 to 20. The results show that chain-extender and higher molecular weight of PPG are able to improve the properties of compatibility, damping and thermal properties.展开更多
In this work, we report the hybrid copolymerization of various cyclic monomers and vinyl monomers. Our studies demonstrate that 1-tert-butyl-4,4,4-tris-（dimethylamino）-2,2-bis[tris（dimethylamino） phophoranyliden-a...In this work, we report the hybrid copolymerization of various cyclic monomers and vinyl monomers. Our studies demonstrate that 1-tert-butyl-4,4,4-tris-（dimethylamino）-2,2-bis[tris（dimethylamino） phophoranyliden-amino]-2A5,A5-catenadi（phosphazene） （t-BuP4） can catalyze the hybrid copolymerization of caprolactone （CL）, lactide （LA） or cyclic carbonate ester with acrylate or methyl acrylate. However, the polymerization of cyclosiloxane with vinyl monomers yields two corresponding homopolymers, and the polymerization of lactone with acrylonitrile （AN） produces only polyacrylonitrile. Clearly, the extent of matching of activity between a monomer and an active center determines whether or not there is hybrid copolymerization.展开更多
基金Project(2003AA84ts04) supported by the National High-Tech Research and Development Program of China
文摘Diglycidyl-4,5-epoxycyclohexane-1,2-dicarboxylate(TDE-85)/methyl tetrahydrophthalic anhydride (MeTHPA) epoxy resin was modified with polyurethane(PU) and the interpenetrating polymer networks(IPNs) of PU-modified TDE-85/MeTHPA resin were prepared. The structural characteristics and properties of PU-modified TDE-85/MeTHPA resin were investigated by Fourier transform infrared(FTIR) spectrum,emission scanning electron microscopy(SEM) and thermogravimetry(TG). The results indicate that epoxy polymer network (Ⅰ) and polyurethane polymer network (Ⅱ) of the modified resin can be obtained and the networks (Ⅰ) and (Ⅱ) interpenetrate and tangle highly each other at the phase interface. The micro morphology presents heterogeneous structure. The integrative properties of PU-modified TDE-85/MeTHPA epoxy resin are improved obviously. The PU-modified TDE-85/ MeTHPA resin's tensile strength reaches 69.39 MPa,the impact strength reaches 23.56 kJ/m,the temperature for the system to lose 1% mass (t1%) is 300 ℃,and that for the system to lose 50% mass (t50%) is 378 ℃. Compared with those of TDE-85/MeTHPA resin,the tensile strength,impact strength,t1% and t50% of the PU-modified resin increases by 48%,115%,30 ℃,11 ℃,respectively. The PU-modified TDE-85/MeTHPA resin has the structure characteristics and properties of interpenetrating polymer networks.
文摘The kinetics of water absorption in water-borne anticorrosive urethane/epoxy coatings, which were actually introduced in the industrial field, are studied. It is found that the high water affinity of a water-borne coating supports a higher saturated water content, Mχ, and helps to facilitate absorption D. The three parameters of stretched exponential function called the William-Watt equation, Eo, τ, and β, are determined to fit the degraded stress relaxation behavior in the water absorption process because this function quantitatively describes the relaxing ability and has been successfully used by a number of researchers. An increasing in the water content is shown to correlate strongly with a decrease in Eo and fl early in the absorption process between Mt/M（χ） = 0 and Mt/Mχ≈ 0.5. The adhesive characteristics of the coatings are correlated with water content, and shown to exhibit higher cohesive failure in coating epoxies under saturated conditions. This suggests that water interferes with the intermolecular bonding between polymer chains which degrades the bulk materials ability to diffuse stress concentrations and reduces its overall strength.
文摘We present comparative life-cycle assessments of three fiber-reinforced sheet molding compounds （SMCs） using kenaf fiber, glass fiber and soy protein resin. Sheet molding compounds for automotive applications are typically made of unsaturated polyester and glass fibers. Replacing these with kenaf fiber or soy protein offers potential environmental benefits. A soy-based resin, maleated acrylated epoxidized soy oil （MAESO）, was synthesized from refined soybean oil. Kenaf fiber and polyester resins were used to make SMC 1 composites, while SMC2 composites were made from kenaf fiber and a resin blend of 20% MASEO and 80% unsaturated polyester. Both exhibited good physical and mechanical properties, though neither was as strong as glass fiber reinforced polyester SMC. The functional unit was defined as mass to achieve equal stiffness and stability for the manufacture of interior parts for automobiles. The life-cycle assessments were done on SMCI, SMC2 and glass fiber reinforced SMC. The material and energy balances from producing one functional unit of three composites were collected from lab experiments and the literature. Key environmental measures were computed using SimaPro software. Kenaf fiber-reinforced SMC composites （SMC1 and SMC2） performed better than glass fiber-reinforced SMC in every environmental category. The global warming potentials of kenaf fiber-reinforced SMC （SMCI） and kenaf soy resin-based SMC （SMC2） were 45% and 58%, respectively, of glass fiber-reinforced SMC. Thus, we have demonstrated significant ecological benefit from replacing glass fiber reinforced SMC with soy-based resin and natural fiber.
文摘This paper studies the structure and properties of the polycarbonate polyurethane epoxy resin (PCPU EP) blends being resistant to hydrolysis.The samples were analyzed by an infrared spectrometer,a differential scanning calorimeter,a scanning electron microscope and a dynamic viscoelastometer.The results show that PCPU EP blends have excellent resistance to hydrolysis and mechanical properties at the ratio of PCPU to EP equal to 10/100 (wt/wt).
文摘Hydroxyl-epoxy phosphate （HEP） as a reactive corrosion inhibitor was innovatively synthe- sized by the reaction of bisphenol A epoxy resin with phosphoric acid. HEP was mixed with hydroxyl acrylate resin, and crosslinked with waterborne isocyanate curing agent, which was used to form waterborne HEP/acrylic polyurethane composite （HEP-APU） coatings on Q235 steel surfaces. Electrochemical impedance spectroscopy and polarization curves were applied to analyze the corrosion behavior of the HEP-APU coatings in 3.5wt% NaCl solutions. The results indicated that the HEP-APU coatings show a superior passivation property and efficient corrosion protection of Q235 steel. The waterborne acrylic polyurethane coating containing 0.5wt% HEP exhibited the best corrosion performance among all the coating specimens. The improved flash-rust resistance can be attributed to the introduction of the phosphate group which could form phosphate film on the steel substrate.
文摘A series of Polyurethane (PU)/bisphenol A based Epoxy Resin(EP) Interpenetrating Polymer Networks(IPN) were synthesized and characterized by SEM, DSC, TGA and DMTA. It was found that IPN shows the best compatibility and damping properties when the ratio of PU/EP is 80 to 20. The results show that chain-extender and higher molecular weight of PPG are able to improve the properties of compatibility, damping and thermal properties.
基金support of the National Basic Research Program of China (2012CB933802) is acknowledged
文摘In this work, we report the hybrid copolymerization of various cyclic monomers and vinyl monomers. Our studies demonstrate that 1-tert-butyl-4,4,4-tris-（dimethylamino）-2,2-bis[tris（dimethylamino） phophoranyliden-amino]-2A5,A5-catenadi（phosphazene） （t-BuP4） can catalyze the hybrid copolymerization of caprolactone （CL）, lactide （LA） or cyclic carbonate ester with acrylate or methyl acrylate. However, the polymerization of cyclosiloxane with vinyl monomers yields two corresponding homopolymers, and the polymerization of lactone with acrylonitrile （AN） produces only polyacrylonitrile. Clearly, the extent of matching of activity between a monomer and an active center determines whether or not there is hybrid copolymerization.
