三嵌段两亲性聚乳酸共聚物的合成及其PVDF共混膜的制备

Synthesis of Triblock Amphiphilic Polylactic Acid Copolymers and Blend Membrane of Copolymer and PVDF

利用原子转移自由基聚合法(ATRP)合成三嵌段两亲性聚乳酸共聚物聚乙烯吡咯烷酮-聚乳酸-聚乙烯吡咯烷酮(PVP-b-PLA-b-PVP),然后将其与聚偏氟乙烯(PVDF)进行共混,制备PVP-b-PLA-b-PVP/PVDF共混膜。结果表明:PVDF膜表面致密,膜断面中指状大孔和海绵状孔同时存在,而共混膜表面多孔,指状大孔贯穿整个断面;与PVDF膜相比,共混膜的孔隙率和孔径增大,水通量提高了158.87%,接触角下降了16.70%,抗污染指标下降了64.7%。

The triblock amphiphitie polylaetie acid copolymer of poly（N-vinylpyrrolidone） bloek-polylactic acid-block-poly（N vinylpyrrolidone）（PVP-b-PLA-b-PVP） was synthesized by atom transfer radical poly- merization（ATRP）, which was blended with polyvinylidene fluoride （PVDF） to fabricate a new type of modified PVDF membrane. Results showed that the surface of PVDF membrane was compact. The finger-like holes and the sponge-like holes coexisted in the cross section of membrane. However, the modified PVDF membrane contained plenty of holes in the surface with finger-like holes which penetrated its cross section. Moreover, compared with PVDF membrane, the blend membrane had a significant increase by 158.87% in water flux, a reduction in the contact angle by 16.7%, and a reduction in the anti-pollution index by 64.7%.