PAN- b- PEG- b- PAN 两亲性嵌段共聚物的合成及热稳定性

以2-溴丙酰溴封端的聚乙二醇（PEG2000）为大分子引发刺，溴化亚铜（CuBr）为催化剂，2，2＇-联吡啶（bpy）为配体，碳酸乙烯酯（EC）为溶剂，采用原子转移自由基聚合（ATRY）法合成了两亲性嵌段共聚物PAN-b-PEG-b-PAN。通过FTIR、^1HNMR和GPC对产物的结构进行了表征，并运用TGA对PAN-b-PEG-b-PAN两亲性嵌段共聚物的热稳定性进行了研究。结果表明：PAN-b-PEG-b-PAN的热稳定性较纯PEG要高，且随着PAN-b-PEG-b-PAN两亲性嵌段共聚物的分子量的增加，此嵌段共聚物的热稳定性增强。它的起始的分解温度为275℃，在275℃-450℃失重较少，失重率约为15％，在400℃-450℃迅速分解，失重率为60％左右。

Study on Synthesis of PAN- b- PEG- b- PAN Amphiphilic Block Copolymers and the thermal stabilities

Poly( ethylene glycol) with 2- Bromopropionyl bromine end group was used as macroinitiator, cupric bromide ( CuBr) as the catalyst, 2, 2c- bipyridine ( bpy) as the ligand, ethylene carbonate ( EC) as a solvent, and the amphiphilic block copolymers of PAN- b- PEG- b- PAN with controlled block length were synthesized using atom transfer radical polymerization ( ATRP) . The amphiphlic block copolymers of PAN- b- PEG- b- PAN were characterized by using FTIR, 1H NMR and GPC. The results showed that the thermal stabilities of PAN - b- PEG- b- PAN were higher than PEG( 2000) , and their thermal stabilities were enhanced with increasing the molecular weight of amphiphilic blockcopolymers of PAN- b- PEG- b- PAN. The first decomposition temperature of them was 275e . The weight of PAN- b- PEG - b- PAN was reduced by 15% at 275e - 450e . They were reduced quickly at 400 e - 450e and about 60% of PAN- b- PEG- b- PAN was reduced.