CAJ | 학술논문

研究了以双硫酯为链转移剂进行的均聚和嵌段共聚物的合成.首先合成大分子链转移剂，得到分子量可控、多分散性系数较小的均聚物PMMA、PBMA、PEMA、PEA、PBA、PMA、PSt，多分散性系数一般小于1.30.在相同的条件下，甲基丙烯酸酯类的聚合速度最快，苯乙烯其次，丙烯酸酯类最慢.用末端带有双硫酯基团的PSt、PBMA、PBA为链转移剂，加入多种第二单体聚合得到实测分子量与理论分子量接近，且多分散性系数较小的两嵌段聚合物.在链转移剂和引发剂的比例为3∶1～6∶1的范围内，聚苯乙烯同样可以作为第一嵌段得到和其它酯类单体的两嵌段聚合物.1H-NMR方法证明了聚合物的末端带有双硫酯基团.嵌段聚合时必须加入微量的自由基引发剂以形成大分子自由基，达到较好的控制聚合效果.
연구료이쌍류지위련전이제진행적균취화감단공취물적합성.수선합성대분자련전이제，득도분자량가공、다분산성계수교소적균취물PMMA、PBMA、PEMA、PEA、PBA、PMA、PSt，다분산성계수일반소우1.30.재상동적조건하，갑기병희산지류적취합속도최쾌，분을희기차，병희산지류최만.용말단대유쌍류지기단적PSt、PBMA、PBA위련전이제，가입다충제이단체취합득도실측분자량여이론분자량접근，차다분산성계수교소적량감단취합물.재련전이제화인발제적비례위3∶1～6∶1적범위내，취분을희동양가이작위제일감단득도화기타지류단체적량감단취합물.1H-NMR방법증명료취합물적말단대유쌍류지기단.감단취합시필수가입미량적자유기인발제이형성대분자자유기，체도교호적공제취합효과.
The syntheses of the homopolymers and diblock copolymers by adding dithioester as chain transfer agent. First a series of monomers:methyl methacrylate (MMA), butyl methacrylate (BMA),methyl acrylate (MA),ethyl acrylate (EA),butyl acrylate (BA), and styrene (St) were polymerized in bulk by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization. All of these homopolymers (PMMA、PBMA、PEA、PBA、PMA、PSt)have the controllable polymerization characteristics, the polydispersity index (PDI) is narrow (1.08～1.30). At the same reaction conditions the rate of polymerization of the methacrylate is the fastest, styrene is slower, acrylate is the slowest. The higher the reaction temperature, the faster the polymerization rate. The effects of the molar ratio of chain transfer agent to initiator on polymerization and the effects of conversion and reaction time on the molar mass characteristics of the prepared block copolymers were discussed. The diblock copolymers have the characteristics of the controlled/living radical polymerization, that is to say that the real molecular-weight of these copolymers is similar to the theoretical molecular-weight, and the polydispersity index is less than 1.80. When the molar ratio of ABIN to CTA is ranged from 1∶3 to 1∶6, the copolymers with PSt as the first block also have characteristics of the controlled/living radical polymerization. The 1H-NMR spectra of the homopolymer (PMMA) and copolymer (PMMA-b-PEA) showed that the synthesized polymers have functional groups, dithioester, at the end of these polymers.