Study On Modification Of Biomedical SEBS And Its Application

Ischemic stroke is a serious cardiovascular disease with high mortality and disability rate and has become one of the main diseases that endanger human health and life safety.Butylphthalide(NBP)is a specific drug for the treatment of ischemic stroke.During intravenous therapy,the infusion devices have absorptive effect on NBP that lead to reduce drug function.In this dissertation,the poly(styrene-b-(ethylene-co-butylene)-b-styrene)(SEBS)with low NBP adsorption was fabricated by grafting Vitamin E derivative(TPGS)with assistance of biomimetic surface modification for the first time.The grafting process of TPGS and NBP adsorptive property were investigated by quartz crystal microbalance with dissipation(QCM-D).Moreover,the composites based on SEBS were fabricated by blending with functional polymers to decrease the NBP adsorption.Details of the research contents and the results are summarized as follows:1.Vitamin E derivative reduce adsorption of Butylphthalide on SEBS surface : A novel biomimetic dopamine(DA)/polyethyleneimine(PEI)copolymerization surface modification technology was used to introduce amino and imino functional groups on the SEBS surface as secondary reaction platform.The results of WCA,FT-IR and XPS revealed that the change of functional group,the improvement of hydrophilicity and the increase content of N element on modified SEBS surfaces,which proved that amino and imino groups were successfully introduced onto the SEBS surfaces and the SEBS-g-PDA,SEBS-g-PEI and SEBS-g-PDA/PEI surfaces structure were successfully prepared.TPGS was introduced by the interaction between the amino,imino groups and the carboxide onto the modified SEBS surfaces.The grafting processes of TPGS and the NBP adsorption behavior were monitored real time by QCM-D.The results of QCM-D revealed that grafted amount of TPGS were improved by introducing amino,imino groups.The relationship between ?D and ?f of TPGS grafted processes revealed that on pristine SEBS surface the TPGS adsorption layer was rigid and the TPGS grafted layer were viscoelastic on the modified SEBS surfaces.The results of NBP adsorption revealed that grafted TPGS on the SEBS-g-PDA,SEBS-g-PEI,SEBS-g-PDA/PEI surfaces could inhibit NBP adsorption and the grafted amount of TPGS was not the determinant of NBP adsorption.The grafted TPGS on SEBS-g-PEI surface formed the optimal viscoelastic layer that showed the same inhibition capacity under the condition of less grafting.The mechanism of TPGS inhibiting NBP adsorption was derived from the hydration of PEG part,the coiled conformation of VE part and the viscoelastic grafted layer of TPGS.2.Preparation of SEBS/Vitamin E derivative composite and its Butylphthalide adsorption.The composites based on SEBS were fabricated by simple physical blending and the NBP adsorptive property of a series of composites was measured by static adsorption method.Adsorption investigation showed that the additive SEBS-g-MAH could improve the capacity of NBP adsorption.Especially the adsorption capacity of NBP of pristine SEBS-g-MAH was three time of that of SEBS,based this we recommend that decrease the application of SEBS-g-MAH as addition agent to produce infusion devices in the industrial production.Adsorption investigation revealed the SEBS/TPGS/PEI composite exhibited low NBP adsorption compared with pristine SEBS,the adsorbance decreased by 33%.In order to save cost,we replaced TPGS with PEG6000 to prepare SEBS/PEG6000 composite which adsorbance decreased by 11%.Considering the low NBP adsorptive property,the prepared composites can broaden the application of SEBS in the basic medical devices field.