Molecular weight characterization of poly(N-isopropylacrylamide) prepared by living free-radical polymerization
Molecular weight characterization of poly(N-isopropylacrylamide) prepared by living free-radical polymerization
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DOI：
10.1021/ma0003102
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发表时间：
2000-09-05
期刊：
影响因子：
5.5
通讯作者：
Rizzardo, E
中科院分区：
文献类型：
--
作者：
Ganachaud, F;Monteiro, MJ;Rizzardo, E
采用可逆加成-断裂链转移(RAFT)法制备了一系列相对单分散的聚N-异丙基丙烯酰胺样品，其相对分子质量范围为2×10(3)~3×10(5)。对于相对分子质量小于4×10(4)的聚合物，找到了使多分散度保持在1.4以下直到高转化率(72%)的条件。用凝胶渗透色谱(GPC)得到的聚合物在THF和MALDI中的分子量分布在低分子量范围内(通常为10(5))是一致的。在凝胶渗透色谱样品制备过程中需要特别注意：必须确保在将聚合物样品在四氢呋喃中溶解之前干燥时，最初存在微量的水，以避免不可逆链聚集。聚NIPAM的特性粘度与相对分子质量的对数/对数图与相对分子质量呈线性关系
A series of relatively monodisperse samples of poly(N-isopropylacrylamide) were synthesized by reversible addition-fragmentation chain transfer (RAFT) over the molecular weight range 2 x 10(3)-3 x 10(5). For molecular weights below 4 x 10(4), conditions were found so that polydispersity remained below 1.4 up to high conversion (72%). Molecular weight distributions of polymer obtained using GPC in THF and MALDI were in accord for the low molecular weight range (typically 10(5)). Particular care is required in GPC sample preparation: it is necessary to ensure that trace amounts of water are initially present when drying a polymer sample prior to dissolution in THF, to avoid irreversible chain aggregation. The log/log plot of intrinsic viscosity against molecular weight for polyNIPAM was found to be linear for molecular weights