Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were p...Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol（mPEG） was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.展开更多
The influence of temperature and mass fraction of Pluonic F127 on the rheological properties of polyvinyl butyric （PVB）/Pluronic F127/polyethylene glycol （PEG） 200 blend systems was investigated by a rotational rh...The influence of temperature and mass fraction of Pluonic F127 on the rheological properties of polyvinyl butyric （PVB）/Pluronic F127/polyethylene glycol （PEG） 200 blend systems was investigated by a rotational rheometer with parallel plates. The results show that the blend systems approach homogeneous state at 140, 150 and 160℃while the rheological properties of the blend systems significantly deviate from the homogeneous systems at 120℃. Shear thinning behavior is observed for all the blend systems at different temperatures and is enhanced by increasing Pluronic F127 content. The complex viscosity, storage modulus, loss modulus, zero-shear activation energy and flow recovery of the blend systems increase with the increase of Pluronic F127 content. There is a crossing point for the loss modulus and the storage modulus of each sample at high frequency, which is called specified frequency （SF）. The loss modulus is larger than the storage modulus when the frequency is less than the SF, and when frequency is more than SF, the loss modulus is smaller than the storage modulus.展开更多
Linear low-density polyethylene(LLDPE) was melt blended with styrene-maleic anhydride copolymer(SMA).The blending films were then immersed in poly(ethylene glycol)400(PEG400) at room temperature.The surface compositio...Linear low-density polyethylene(LLDPE) was melt blended with styrene-maleic anhydride copolymer(SMA).The blending films were then immersed in poly(ethylene glycol)400(PEG400) at room temperature.The surface composition of the blend films was determined by Fourier transform infra-red spectroscopy coupled with an variable incidence angle attenuated total reflection accessory(ATR-FTIR).It has been found that PEG400 was grafted onto the surface of the films via esterification with SMA.PEG immersion promoted enrichment of SMA onto the surface of the films.The water contact angle data show that grafting of PEG400 can greatly improve the hydrophilicity of the PE surface.These experiments show that surface functionalization of polyethylene films by blending SMA and then surface grafting of PEG is a feasible process,which suggest a viable and simple route for PE surface modification via blending and grafting.展开更多
基金Supported by the National Natural Science Foundation of China(No.29405038)
文摘Preparation and blood compatibility of different shape polyvinyl alcohol（PVA） membrane were investigated. Firstly, the tabular and tubular[polytetrafluoroethylene（PTFE） capillary as supporter] PVA membranes were prepared; then, methoxy polyethylene glycol（mPEG） was grafted onto the surface of the PVA membranes. The effects of the shape, structure and properties of the membrane surface on blood compatibility were studied in detail. The experiment results show that mPEG modified PVA membranes, especially mPEG modified tubular membrane, could availably repel the adhesion of the platelets. In addition, the anticoagulant mechanism of mPEG with a steric repulsion effectiveness was confirmed further via different grafting methods.
基金Project(20776161) supported by the National Natural Science Foundation of China
文摘The influence of temperature and mass fraction of Pluonic F127 on the rheological properties of polyvinyl butyric （PVB）/Pluronic F127/polyethylene glycol （PEG） 200 blend systems was investigated by a rotational rheometer with parallel plates. The results show that the blend systems approach homogeneous state at 140, 150 and 160℃while the rheological properties of the blend systems significantly deviate from the homogeneous systems at 120℃. Shear thinning behavior is observed for all the blend systems at different temperatures and is enhanced by increasing Pluronic F127 content. The complex viscosity, storage modulus, loss modulus, zero-shear activation energy and flow recovery of the blend systems increase with the increase of Pluronic F127 content. There is a crossing point for the loss modulus and the storage modulus of each sample at high frequency, which is called specified frequency （SF）. The loss modulus is larger than the storage modulus when the frequency is less than the SF, and when frequency is more than SF, the loss modulus is smaller than the storage modulus.
文摘Linear low-density polyethylene(LLDPE) was melt blended with styrene-maleic anhydride copolymer(SMA).The blending films were then immersed in poly(ethylene glycol)400(PEG400) at room temperature.The surface composition of the blend films was determined by Fourier transform infra-red spectroscopy coupled with an variable incidence angle attenuated total reflection accessory(ATR-FTIR).It has been found that PEG400 was grafted onto the surface of the films via esterification with SMA.PEG immersion promoted enrichment of SMA onto the surface of the films.The water contact angle data show that grafting of PEG400 can greatly improve the hydrophilicity of the PE surface.These experiments show that surface functionalization of polyethylene films by blending SMA and then surface grafting of PEG is a feasible process,which suggest a viable and simple route for PE surface modification via blending and grafting.
