PLA大分子单体接枝NVP共聚物的合成与性能

制备了末端为双键的功能化聚乳酸大分子单体(PLA-HEMA),并以此大分子单体与N-乙烯基吡咯烷酮(NVP)进行自由基溶液共聚,合成了具有亲水性PVP-PHEMA主链和疏水性PLA支链的接枝共聚物。用FT-IR1、H-NMR、GPC、DSC、表面接触角测定研究了共聚物的结构与性能。结果表明:共聚物为非晶聚合物;NVP的摩尔投料量对共聚物的性能有显著影响,随NVP投料量增大,共聚物的分子量有所下降,玻璃化转变温度(Tg)增大;由于亲水性PVP和PHEMA链段的引入,共聚物的亲水性优于相应的线型聚乳酸材料。

Synthesis and Properties of a Graft Copolymer Derived from Poly(D,L-lactide) Macromonomer and N-Vinyl Pyrrolidone

Poly(D,L-lactide) macromonomer(PLA-HEMA) carrying the acrylate group was first prepared.Then,the graft copolymers with hydrophilic PVP-PHEMA backbone and hydrophobic PLA branched chain were synthesized by the free radical copolymerization of PLA-HEMA with(N-vinyl) pyrrolidone(NVP) in solution.The structure and properties of the graft copolymers were studied by FT-IR,()~1H-NMR,GPC,DSC and surface contact angle measurements.Results show that the graft copolymers are amorphous polymers.The feed molar fraction of NVP has significant influence on the properties of the copolymers.The molecular weight of the copolymers decreases and the value of the glass transition temperature(T_g) increases as the feed molar fraction of NVP increases.Compared to pure PLA,the graft copolymers show higher hydrophilicity due to the incorporation of hydrophilic PVP and PHEMA units in the copolymers.