Hamersky Mark W, Smith Steven D, Gozen Arif O, Spontak Richard J
Miami Valley Innovation Center, The Procter & Gamble Company, Cincinnati, Ohio 45061, USA.
Phys Rev Lett. 2005 Oct 14;95(16):168306. doi: 10.1103/PhysRevLett.95.168306.
The transformation from A(1)B diblock copolymer to A(1)BA(2) triblock copolymers varying in molecular asymmetry is investigated as the A(2) end block is progressively grown via chemical synthesis. Dynamic rheological measurements show that the order-disorder transition (ODT) temperatures of two copolymer series differing in composition and molecular weight decrease when the A(2) block is short relative to the A(1) block, and then increase as the length of the A(2) block is increased further. The resultant ODT minimum, predicted by mean-field theory, is attributed to mixing between long B and short A(2) blocks.
随着 A(2) 端嵌段通过化学合成逐渐生长，研究了从 A(1)B 二嵌段共聚物到分子不对称性不同的 A(1)BA(2) 三嵌段共聚物的转变。动态流变学测量表明，当 A(2) 嵌段相对于 A(1) 嵌段较短时，组成和分子量不同的两个共聚物系列的有序-无序转变（ODT）温度会降低，然后随着 A(2) 嵌段长度的进一步增加而升高。平均场理论预测的所得 ODT 最小值归因于长 B 嵌段和短 A(2) 嵌段之间的混合。
