In this paper,morphological structure,thermodynamic compatibility and relationship be-tween porosities and blend ratios of the wet coagulated PU/PVA sheets were studied by meansof observation of scanning electronic mi...In this paper,morphological structure,thermodynamic compatibility and relationship be-tween porosities and blend ratios of the wet coagulated PU/PVA sheets were studied by meansof observation of scanning electronic micrographies,tests of dynamic mechanical properties,moisture regain and vapor permeability.Furthermore,the formation of microvoids at interfacesof separated phases was discussed and a microvoid formation mechanism at phase interfaces ofhydrophobic-hydrophilic blends was suggested and compared with that ofhydrophobic-hydrophobic blends.展开更多
A polyurea-chlorocyclophosphazene microcapsule flame retardant is prepared by an interfacial polymerization process using 2,4-toluene diisocyanate (TDI) and hexanediamine as the raw materials. TG tests show that the t...A polyurea-chlorocyclophosphazene microcapsule flame retardant is prepared by an interfacial polymerization process using 2,4-toluene diisocyanate (TDI) and hexanediamine as the raw materials. TG tests show that the thermal decomposition temperature of chlorocyclophosphazene in microcapsule obviously rises. The flame retardancy of HDPE/chlorocyclophosphazene in microencapsules is better than that of HDPE/chlorocyclophosphazene. Mechanical properties of HDPE/chlorocyclophosphazene microencapsule turn out to be superior to those of HDPE/chlorocyclophosphazene.展开更多
Appropriate surface modification or functionalization is prerequisite for the application of inorganic nanoparticles.And surface control between organic and inorganic interface plays an important role in constructing ...Appropriate surface modification or functionalization is prerequisite for the application of inorganic nanoparticles.And surface control between organic and inorganic interface plays an important role in constructing organic-inorganic composites.In-situ polymerization has been extensively studied to improve the compatibility and dispersibility of inorganic nanoparticles,but the polymerized nanoparticles tend to concatenate and form large composites,restricting further applications.Herein,uniform and dense polyacrylic acid(PAA)membranes have been grafted on layered double hydroxide(LDH)nanosheets via an in-situ initiating and terminating radical graft polymerization method.With initiating and terminating on the same particle,the size,morphology and density of grafted PAA onto the surface of LDHs can be controlled by adjusting the ratio of initiated sites to terminated sites,the amount of redox initiator or monomer.As a result,with only 17.33%organic grafting ratio,PAA@LDHs with largely improved compatibility can be monodispersed in polyethylene(PE)and polyvinyl chloride(PVC)matrices,which is determined by a fluorescence microscope technique.展开更多
文摘In this paper,morphological structure,thermodynamic compatibility and relationship be-tween porosities and blend ratios of the wet coagulated PU/PVA sheets were studied by meansof observation of scanning electronic micrographies,tests of dynamic mechanical properties,moisture regain and vapor permeability.Furthermore,the formation of microvoids at interfacesof separated phases was discussed and a microvoid formation mechanism at phase interfaces ofhydrophobic-hydrophilic blends was suggested and compared with that ofhydrophobic-hydrophobic blends.
基金Natural Science Foundation of Shanxi Province (20041029)Project of Science and Technology of Shanxi Province (012078)
文摘A polyurea-chlorocyclophosphazene microcapsule flame retardant is prepared by an interfacial polymerization process using 2,4-toluene diisocyanate (TDI) and hexanediamine as the raw materials. TG tests show that the thermal decomposition temperature of chlorocyclophosphazene in microcapsule obviously rises. The flame retardancy of HDPE/chlorocyclophosphazene in microencapsules is better than that of HDPE/chlorocyclophosphazene. Mechanical properties of HDPE/chlorocyclophosphazene microencapsule turn out to be superior to those of HDPE/chlorocyclophosphazene.
基金supported by the National Natural Science Foundation of China(Nos.21776018,21627813,U170760003,21521005,and 21905014)the Qinghai Provincial Major Science and Technology Special Project(No.2020-GX-A1)the Key R&D Program of Gansu Province(No.19YF3GA003).
文摘Appropriate surface modification or functionalization is prerequisite for the application of inorganic nanoparticles.And surface control between organic and inorganic interface plays an important role in constructing organic-inorganic composites.In-situ polymerization has been extensively studied to improve the compatibility and dispersibility of inorganic nanoparticles,but the polymerized nanoparticles tend to concatenate and form large composites,restricting further applications.Herein,uniform and dense polyacrylic acid(PAA)membranes have been grafted on layered double hydroxide(LDH)nanosheets via an in-situ initiating and terminating radical graft polymerization method.With initiating and terminating on the same particle,the size,morphology and density of grafted PAA onto the surface of LDHs can be controlled by adjusting the ratio of initiated sites to terminated sites,the amount of redox initiator or monomer.As a result,with only 17.33%organic grafting ratio,PAA@LDHs with largely improved compatibility can be monodispersed in polyethylene(PE)and polyvinyl chloride(PVC)matrices,which is determined by a fluorescence microscope technique.
