The acetone solution of dimethyldioxirane was prepared with caroate (KHSO5) andacetone.This solution can be kept at low temperature(-20℃) for days. It is much conve-nient to use the oxidant for the epoxidation of car...The acetone solution of dimethyldioxirane was prepared with caroate (KHSO5) andacetone.This solution can be kept at low temperature(-20℃) for days. It is much conve-nient to use the oxidant for the epoxidation of carbon carbon double bonds in some unsaturat-ed natural products. Five unsaturated compounds were oxidized to the corresponding epox-ides with dimethyldioxirane and the reaction selectivity was discussed.展开更多
Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behavi...Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behaviors of three types of epoxy SMPs with varying curing agent contents were investigated using a molecular dynamics(MD) method. The mechanical properties under uniaxial tension at different temperatures were obtained, and the simulation results compared reasonably with experimental data. In addition, in a thermomechanical cycle, ideal shape memory effects for the three types of SMPs were revealed through the shape frozen and shape recovery responses at low and high temperatures, respectively, indicating that the recovery time is strongly influenced by the ratio of E-51 to 4,4'-Methylenedianiline.展开更多
文摘The acetone solution of dimethyldioxirane was prepared with caroate (KHSO5) andacetone.This solution can be kept at low temperature(-20℃) for days. It is much conve-nient to use the oxidant for the epoxidation of carbon carbon double bonds in some unsaturat-ed natural products. Five unsaturated compounds were oxidized to the corresponding epox-ides with dimethyldioxirane and the reaction selectivity was discussed.
基金the National Natural Science Foundation of China(Grant Nos.11272044 and 11023001)
文摘Following deformation, thermally induced shape memory polymers(SMPs) have the ability to recover their original shape with a change in temperature. In this work, the thermomechanical properties and shape memory behaviors of three types of epoxy SMPs with varying curing agent contents were investigated using a molecular dynamics(MD) method. The mechanical properties under uniaxial tension at different temperatures were obtained, and the simulation results compared reasonably with experimental data. In addition, in a thermomechanical cycle, ideal shape memory effects for the three types of SMPs were revealed through the shape frozen and shape recovery responses at low and high temperatures, respectively, indicating that the recovery time is strongly influenced by the ratio of E-51 to 4,4'-Methylenedianiline.
