Interpenetrating polymer networks （IPNs） composed of acrylate-modified polyurethane （PU）/unsaturated polyester （UP） resin via simultaneous polymerization with various component ratios of PU/UP were prepared. The...Interpenetrating polymer networks （IPNs） composed of acrylate-modified polyurethane （PU）/unsaturated polyester （UP） resin via simultaneous polymerization with various component ratios of PU/UP were prepared. The polymerization processes of IPNs were traced through infrared spectrum （IR） techniques, by which the phase separation in systems could be controlled effectively. Results for the morphology and miscibility among multiple phases of IPNs, obtained by transmission electron microscope （TEM） indicated that the domains between two phases were constricted in nanometer scales. The dynamic mechanical thermal analyzer （DMTA） detection results revealed that the loss factor （tanS） and loss modulus （E″） increased with the polyurethane amounts in system, and the peak value in curves of tanδ and E″ appeared toward low temperature ranges. Maximum tanδ values of all samples were above 0.3 in the nearly 50℃ ranges. Also, the mechanical properties of PU/UP IPNs were studied in detail.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
BaTiO3/ Interpenetrating Polymer Networks (IPNs) composites were prepared by combination of BaTiO3 nanocrystal in tetragonal system and polyurethane(PU)/ unsaturated polyester (UP) interpenetrating polymer networks (I...BaTiO3/ Interpenetrating Polymer Networks (IPNs) composites were prepared by combination of BaTiO3 nanocrystal in tetragonal system and polyurethane(PU)/ unsaturated polyester (UP) interpenetrating polymer networks (IPNs). The tetra gonal nanocrystalline BaTiO3 was obtained by hydrothermal process and calcinatio n at 1 200 ℃. The prepared materials were polarized with high voltage a nd small current, and protected by silicon oil. The morphology of BaTiO3/ IPNs and the effect of combination of BaTiO3 on the damping behavior of IPNs were stu died. The relationship between damping performance and dielectric charater was a lso discussed in terms of dielectric constant and dielectric loss measured. The results show that the areas under loss modulus (E″) and the values of loss fact ors (tanBaTiO3 into IPNs system. The m aximum value of E″ increased above 100 MPa compared with pure IPNs and the exte nt increased more remarkably after polarizing process. The main and shoulder pea k of tand the temperatu re ranges of tan℃. Moreover, through polarizing proc ess, the composites exhibited synergistic action caused by elastomeric damping, interfacial abrasive damping and piezoelectric damping mechanisms. The relations hip study of damping property and dielectric characters showed that the temperat ure ranges exhibited excellent consistency of maximum dielectric loss and modulu s with damping loss factor.展开更多
基金supported by the Scientific Research Foundation of Harbin Institute of Technology(HIT.2002.56)the Postdoctoral Foundation of Heilongjiang Province,China
文摘Interpenetrating polymer networks （IPNs） composed of acrylate-modified polyurethane （PU）/unsaturated polyester （UP） resin via simultaneous polymerization with various component ratios of PU/UP were prepared. The polymerization processes of IPNs were traced through infrared spectrum （IR） techniques, by which the phase separation in systems could be controlled effectively. Results for the morphology and miscibility among multiple phases of IPNs, obtained by transmission electron microscope （TEM） indicated that the domains between two phases were constricted in nanometer scales. The dynamic mechanical thermal analyzer （DMTA） detection results revealed that the loss factor （tanS） and loss modulus （E″） increased with the polyurethane amounts in system, and the peak value in curves of tanδ and E″ appeared toward low temperature ranges. Maximum tanδ values of all samples were above 0.3 in the nearly 50℃ ranges. Also, the mechanical properties of PU/UP IPNs were studied in detail.
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.
文摘BaTiO3/ Interpenetrating Polymer Networks (IPNs) composites were prepared by combination of BaTiO3 nanocrystal in tetragonal system and polyurethane(PU)/ unsaturated polyester (UP) interpenetrating polymer networks (IPNs). The tetra gonal nanocrystalline BaTiO3 was obtained by hydrothermal process and calcinatio n at 1 200 ℃. The prepared materials were polarized with high voltage a nd small current, and protected by silicon oil. The morphology of BaTiO3/ IPNs and the effect of combination of BaTiO3 on the damping behavior of IPNs were stu died. The relationship between damping performance and dielectric charater was a lso discussed in terms of dielectric constant and dielectric loss measured. The results show that the areas under loss modulus (E″) and the values of loss fact ors (tanBaTiO3 into IPNs system. The m aximum value of E″ increased above 100 MPa compared with pure IPNs and the exte nt increased more remarkably after polarizing process. The main and shoulder pea k of tand the temperatu re ranges of tan℃. Moreover, through polarizing proc ess, the composites exhibited synergistic action caused by elastomeric damping, interfacial abrasive damping and piezoelectric damping mechanisms. The relations hip study of damping property and dielectric characters showed that the temperat ure ranges exhibited excellent consistency of maximum dielectric loss and modulu s with damping loss factor.
