Influence of molecular features on the tackiness of acrylic polymer melts
Influence of molecular features on the tackiness of acrylic polymer melts
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DOI：
10.1021/ma0020279
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发表时间：
2001-10-09
期刊：
影响因子：
5.5
通讯作者：
Shull, KR
中科院分区：
文献类型：
--
作者：
Lakrout, H;Creton, C;Shull, KR
研究了分子量和丙烯酸含量对一系列单分散聚丙烯酸正丁酯材料粘接性能的影响。这些模型压敏胶粘剂的短期粘附性，或“粘性”，通过进行探针粘性实验来量化。这些实验包括一个键合阶段，在这个阶段，一个扁平的冲头与PnBA层接触，然后是一个脱键阶段，在这个阶段，探针被拉离表面。脱粘过程分为三种不同的变形机制：(1)整个粘接层出现空腔；(2)这些空腔在粘附层平面内的横向生长；(3)纤维状结构的形成和最终破坏，因为粘合剂在施加拉伸载荷的方向上延伸。空化主要取决于胶粘剂的弹性特性，但在实验的时间尺度上，胶粘剂的流动能力对侧向空化的生长和扩展机制有很大的影响。这些过程的性质由有效的黛博拉数决定，该数定义为聚合物的终端松弛时间乘以脱粘过程中施加的初始应变速率。
The effects of molecular weight and acrylic acid content on the adhesive properties of a series of monodisperse poly(n-butyl acrylate) materials have been investigated. The short-time adhesion, or "tackiness", of these model pressure-sensitive adhesives was quantified by performing probe-tack experiments. These experiments consist of a bonding phase, where a flat punch is brought into contact with a PnBA layer, and a subsequent debonding phase, where the probe is pulled away from the surface. The debonding process was separated into three distinct deformation mechanisms: (1) the appearance of cavities throughout the adhesive layer; (2) lateral growth of these cavities within the plane of the adhesive layer; (3) the formation and eventual failure of a fibrillar structure as the adhesive is extended in the direction of the applied tensile load. Cavitation depends primarily on the elastic character of the adhesive, but the lateral cavity growth and extensional mechanisms are strongly affected by the ability of the adhesive to flow during the time scale of the experiment. The nature of these processes was determined by an effective Deborah number, defined as the terminal relaxation time of the polymer multiplied by the initial strain rate imposed during the debonding process.