梳形支化聚苯乙烯的支化结构对其溶液形态和性质的影响

Influence of Branching Structure on Morphologies and Properties of Comb-Like Branched Polystyrene

通过氮氧稳定自由基聚合和原子转移自由基聚合制备出不同支化结构的梳形支化聚苯乙烯。使用示差折光指数-多角激光光散射-毛细管黏度三检测联用凝胶渗透色谱对不同链结构梳形支化聚苯乙烯在四氢呋喃(THF)中的形态和性质进行了研究。结果表明,梳形支化PS在THF中的均方根回转半径(Rg)和特性黏数([η])均随支链长度和支链数目的增加而增大,但是在支链长度较长或者支链数目较大时,Rg和[η]随分子量增加而增大的趋势逐渐放缓,而且支链数目对梳形支化PS在溶液中的均方根回转半径和特性黏数的影响程度要大于支链长度。梳形支化聚苯乙烯在四氢呋喃中的MHS方程特性参数K、α随支链长度和支链数目的增加不断变化。

Comb-like branched polystyrenes with different branching structures were dissolved in tetra- hydrofuran （THF）, and root mean square radius of gyration （Rg） and intrinsic viscosity （[η]） in solution were measured using multi-detection GPC with refractive index, viscosity and multiangle light-scattering detectors （GPC-RI-MALLS-DV）. Results showed that Rg and [η] of comb-like branched polystyrene increased with the increasing of branch lengths and branch numbers, and demonstrated linear relationship with molecular weights. However, as the branch lengths and the branch numbers increased, the increased trend of Rg and [η] with the increasing of molecular weight slowed down gradually. The influence extent of branch numbers on Rg and [η] was larger than branch length. In addition, the values of K and a of the MHS equation parameters of comb-like branched polystyrene in THF changed with the increasing of branch lengths and branch numbers.