The Effect of Monomer Sequence Distributions in Copolymers: Phase Behavior and Interfacial Properties

胶粘剂、光刻胶、冲击改性剂、包装材料和乳化剂都是共聚物的工业用途。共聚物包含两种或两种以上类型的单体单元，它们以共价键连接在一条聚合物链上。共聚物的不同单体单元可以以各种顺序排列，例如，随机排列、交替排列和嵌段排列。传统上，研究人员认为序列分布不会影响宏观性质，除非在序列差异非常大的情况下，例如随机与嵌段共聚物。然而，包括作者的工作在内的一些研究表明，序列分布的微小差异会显著影响混合混相性。鉴于这些意想不到的结果，将对序列分布对热力学和力学性能的影响进行深入的研究。相关课题是共聚物/均聚物/均聚物共混物的相行为和共聚物在非混相之间的界面性质。共混混相和界面断裂韧性将主要作为共聚物序列分布的函数来研究，尽管也会对相互作用参数和分子量给予相当的关注。共聚物中的序列分布将作为一种通过改变分子结构来有效地裁剪性能的新手段进行探索。＊＊＊

9307993 Winey Adhesives, photoresists, impact modifiers, packaging materials, and emulsifying agents are among the industrial uses of copolymers. Copolymers contain two or more types of monomer units covalently bonded to one another in a single polymer chain. The different monomer units of the copolymer can be arranged in a variety of sequences, for example, random, alternating, and block. Traditionally, researchers have assumed that the sequence distribution does not influence macroscopic properties, except in the case of very large sequencing differences, for example random versus block copolymers. However, a few studies, including work by the authors, have demonstrated that small differences in the sequence distribution dramatically influence blend miscibility. Given these unexpected results, a thorough investigation of the effect of sequence distribution on thermodynamics and mechanical properties will be carried out. The pertinent topics are the phase behavior in copolymer/homopolymer/homopolymer blends and the interfacial properties of copolymer confined between immiscible phases. Both blend miscibility and interfacial fracture toughness will be studied primarily as a function of the sequence distribution of the copolymer, though considerable attention will also be given to the interaction parameter and molecular weights. The sequence distribution in copolymers will be explored as a new means of effectively tailoring properties by varying the molecular structure. ***