含氟接枝共聚物的合成与表征

苯乙烯(St)与对氯甲基苯乙烯(CMS)进行自由基共聚制得共聚物(PSC),用PSC引发甲基丙烯酸十二氟庚酯进行原子转移自由基聚合(ATRP),制得含氟接枝共聚物(PGF)。利用红外光谱(FT-IR)、核磁共振(1H-NMR)、差示扫描量热(DSC)和凝胶渗透色谱(GPC)对其结构和性能进行表征。结果表明,当含氟单体转化率相近时,支链长度(Mn,s)随PGF的支链数目增加而减少;随着Mn,s的增加,成膜温度对PGF疏水性能的影响越明显;Mn,s为1142时,PGF有83℃和94℃两个玻璃化转变温度(Tg),均比PSC的Tg(103℃)低。

Synthesis and Characterization of Graft Fluoropolymer

A graft fluoropolymer (PGF) was synthesized by atom transfer radical polymerization (ATRP) using dodecafluoroheptyl methacrylate (DMA) as monomer, with the copolymer(PSC) of styrene(St) and 4-chloromethyl styrene(CMS) as macroinitiator, which was first synthesized by solution copolymerization at 80 ℃ with dibenzoyl peroxide as initiator.Fourier transform infrared spectroscopic(FT-IR), hydrogen nuclear magnetic resonance spectrum(1H-NMR), differential scanning calorimetry (DSC) and gel permeation in chromatography(GPC) were used to characterize the structure of the prepared products.The results show that the number-average molecular weight of side chains (Mn,s) of PGF decreases as the number of side chains increases at similar DMA conversion.As Mn,s increases, the influence of film temperatures on the hydrophobility of PGF becomes more obvious.The graft fluoropolymer (Mn,s =1142) has two glass-transition temperature (Tg)values(83 ℃ and 94 ℃), which are lower than the Tg of PSC(103 ℃).