4-臂和7-臂星形支化聚苯乙烯的合成及其溶液性质

FOUR-AND SEVEN-ARM STAR POLYSTYRENES: THEIR PREPARATION AND SOLUTION PROPERTIES

本文合成了不同分子量的5个4-臀星形聚苯乙烯和4个7-臂星形聚苯乙烯试样,用GPC粘度计联用装置对之进行了测定。提出了一种用良溶剂中的粘度数据,通过线性外推方法,得到θ条件下的g’θ因子(=[η]b,θ/[η]l,θ)的理论处理方法。对良溶剂中的g’因子（=[η]b/[η]l）和g’θ因子之间的差异以及g’θ因子与gθ因子(=Sb,θz/Sl,θz)间关系式g’θ=g’θ∈中的∈选值问题进行了详细的讨论,结果证实,∈不仅与支化类型有关,而且与支化程度有关,对4-臂星形聚苯乙烯,∈=1.487,而对7-臂星形聚苯乙烯,∈=1.14。4-臂星形聚苯乙烯的g’和g’θ因子差别较小;对7-臂星形聚苯乙烯,两者间差别较大,不可忽视。

Five 4-arm-and four 7-arm-star shaped polystyrene samples different in molecular weight have been prepared and examined by GPC combined viscosimetry. A theoretical treatment method is proposed to obtain the factor g'θ(=[η]b,θ/[η]l.θ.)from viscosity in good solvent. The difference between the factor g(=[η]b/[η]l) and g'θ,as well as the ∈-value in the relationship between g'θ, and gθ( =S_(b,θ)~2/S_(i,θ)~), (g'θ=g_θ~ε) have been discussed.The results verified that the ∈-value not only depends on the type of branching, but also depends on the degree of branching, ∈=1.487 and 1.14 for 4-arm and 7-arm star polystyrene, respectively. The difference between g' and g'θ is smaller for 4-arm star polystyrene, but is larger for 7-arm star polystyrene.