Uchida S, Takeda H, Ishizu K
Department of Polymer Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8552, Japan
J Colloid Interface Sci. 1999 May 1;213(1):62-67. doi: 10.1006/jcis.1999.6102.
Gradient-modulus star copolymers were synthesized by crosslinking of polystyrene/isoprene tapered anions with divinylbenzene in benzene. The styrene content in the tapered arm was determined by 1H-nuclear magnetic resonance as a parameter of conversion. The composition of the arm showed the gradient structure and was in good agreement with that calculated by reactivity ratios. The solution properties of gradient-modulus star copolymers were examined by static and dynamic light scatterings. The structural ordering of gradient-modulus star copolymers were investigated by means of small-angle X-ray scattering. Gradient-modulus star copolymers formed a body-centered cubic (BCC) structure near the overlap threshold (C*). Above C*, this structure changed to the mixed lattice of BCC and face-centered cubic (FCC) structures. Copyright 1999 Academic Press.
通过在苯中用二乙烯基苯使聚苯乙烯/异戊二烯渐变阴离子交联来合成梯度模量星形共聚物。通过1H-核磁共振测定渐变臂中的苯乙烯含量作为转化率的参数。臂的组成呈现梯度结构，并且与通过竞聚率计算得到的结果吻合良好。通过静态和动态光散射研究了梯度模量星形共聚物的溶液性质。借助小角X射线散射研究了梯度模量星形共聚物的结构有序性。梯度模量星形共聚物在重叠阈值（C*）附近形成体心立方（BCC）结构。高于C*时，这种结构转变为BCC和面心立方（FCC）结构的混合晶格。版权所有1999年学术出版社。
