Poly(styrene-alt-maleic anhydride)-block-poly(methacrylate-ran-styrene) block copolymers with tunable mechanical properties by nitroxide mediated controlled radical polymerization
Poly(styrene-alt-maleic anhydride)-block-poly(methacrylate-ran-styrene) block copolymers with tunable mechanical properties by nitroxide mediated controlled radical polymerization
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DOI：
10.1007/s13233-016-4096-3
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发表时间：
2016-09
影响因子：
2.4
通讯作者：
B. Lessard;S. Mackay;Adrien Métafiot;M. Maríc
中科院分区：
文献类型：
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作者：
B. Lessard;S. Mackay;Adrien Métafiot;M. Maríc
聚（苯乙烯-alt-马来酸酐）-嵌段聚以低分散性的聚苯乙烯（MMA-RAN-St）为原料合成了嵌段共聚物（Mw/Mn=1.24）和完全交替聚（苯乙烯-alt-马来酸酐）大分子引发剂，通过氮氧介导的受控自由基聚合（NMP），使用各种富含甲基丙烯酸酯的混合物：甲基丙烯酸甲酯/苯乙烯（MMA/S）、甲基丙烯酸乙酯/苯乙烯（EMMA/S）、甲基丙烯酸正丁酯/苯乙烯（BMA/S）和甲基丙烯酸苄酯/苯乙烯（BzMA/S）。在大分子引发剂的扩链过程中存在一些不可逆的终止，导致最终嵌段共聚物的分子量分布中的一些双峰性（约2%至约25%的死链），这对于通过NMP的甲基丙烯酸酯/苯乙烯共聚是常见的。通过1H NMR测定得到的最终嵌段共聚物富含甲基丙烯酸酯（摩尔比XMA/S = 3.3 ~ 5.5），并且发现得到的扩链段的玻璃化转变温度（Tg）与相应的纯聚（甲基丙烯酸酯）类似。NMP允许通过简单取代合成中使用的甲基丙烯酸酯单体来控制含官能马来酸酐的链段在具有可调机械性能的嵌段共聚物内的位置。
Poly(styrene-alt-maleic anhydride)-block-poly(methacrylate-ran-styrene) block copolymers were synthesized from low dispersity (Mw/Mn=1.24) and perfectly alternating poly(styrene-alt-maleic anhydride) macroinitiators, by nitroxide mediated controlled radical polymerization (NMP), using various methacrylate-rich mixtures: methyl methacrylate/styrene (MMA/S), ethyl methacrylate/styrene (EMMA/S),n-butyl methacrylate/styrene (BMA/S) and benzyl methacrylate/styrene (BzMA/S). Some irreversible termination was present during the chain extension from the macroinitiator, resulting in some bimodality in the molecular weight distribution of the final block copolymer (≈2% to ≈25% dead chains) which is common for methacrylate/styrene copolymerizations by NMP. The resulting final block copolymers were determined to be methacrylate-rich (molar ratio XMA/S ≈3.3 to 5.5) by1H NMR and the resulting glass transition temperature (Tg) of the chain-extended segments were found to be similar to the coresponding pure poly(methacrylate)s. NMP allows the controlled placement of functional maleic anhydride containing segments within a block copolymer with tunable mechanical properties by simple substitution of methacrylate monomer used in synthesis.