Chain Conformation in Latex Particles and Their Diffusion During Film Formation as Characterized by Small-Angle Neutron Scattering

涂料和表面涂料是由分散在水相中的胶体聚合物颗粒(也称为乳胶)组成的悬浮液。这些悬浮液是通过乳液聚合产生的，这是一种多相过程，聚合物在油相中生长，引发剂和单体从水相扩散到油相中。将悬浮液涂在表面并干燥，最初形成一层弱乳胶膜。几天后，它们的强度会增加，变得坚韧和坚韧。在这项研究中，将证明这种薄膜的形成是因为聚合物层通过单个链在初始束上的相互扩散而形成整体卷曲--即，一旦聚合物链从胶乳的限制中释放出来，就会膨胀并试图达到其随机卷曲的构型。小角中子散射(SANS)被用来观察这些高分子量聚合物在其形成过程中和干燥后的凝固阶段的表现。对这一行为的了解可以用来设计其他高强度聚合物，如液晶。

Paints and surface coatings are suspensions consisting of colloidal polymer particles dispersed in an aqueous phase (also called latexes). These suspensions are produced via emulsion polymerization, a heterogeneous process in which polymers grow in an oily phase into which initiators and monomers diffuse from the aqueous phase. The suspension is applied to a surface and dries, initially forming a weak latex film. After a few days these increase in strength and become tough and leathery. In this research, it will be proved that this film formation occurs because the polymer layers form monolithic colids by interdiffusion of individual chains across initial bundaries--i.e., the polymer chains, once freed from the confines of the latex, expand and try to attain their random coil configurations. Small-angle neutron scattering (SANS) is used to look at how these high molecular weight polymers behave both during their formation and during the setting stage after drying. Knowledge of this behavior can then be used to design other high strength polymers such as liquid crystals.