The effect of polymer molecular weight and crosslinking reactions on the adhesion properties of microsphere water-based acrylic pressure-sensitive adhesives
The effect of polymer molecular weight and crosslinking reactions on the adhesion properties of microsphere water-based acrylic pressure-sensitive adhesives
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DOI：
10.1016/j.ijadhadh.2008.04.012
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发表时间：
2009-03-01
影响因子：
3.4
通讯作者：
Krajnc, M.
中科院分区：
文献类型：
--
作者：
Kajtna, J.;Golob, J.;Krajnc, M.
研究了聚合物分子量和交联反应对微球型水性丙烯酸酯压敏胶（PSA）最终使用性能的影响。使用不同的链转移剂（CTA）浓度和通过添加二丙烯酸单体（MM）调节聚合物分子量和聚合物微观结构。通过测定粘着力、剥离力和剪切强度来表征合成的PSA的粘附性能。实验结果表明，CTA和MM用量对悬浮聚合反应动力学影响不大，随着CTA用量的增加，胶液中凝胶相的数量减少，凝胶相的数量与聚合物分子量有关。通过CTA和MM的组合，可以调节粘合剂中形成的凝胶相的量以及溶胶相分子量。所有测得的粘附性能强烈地依赖于合成的聚合物的油分子量和凝胶相的量。对于仅用添加CIA合成的粘合剂，粘性随着较低的聚合物分子量而降低，并且连续地也随着较低量的凝胶相而降低。对于剥离强度测量也观察到相同的趋势，而对于具有低量凝胶相的粘合剂观察到内聚破坏。在80重量%的凝胶相时观察到粘性和剪切强度的最大值。在用CTA和MM的组合（凝胶相的量在70至80重量%的范围内）合成的情况下，粘性值分布在相当窄的范围内。另一方面，与仅用CTA合成的粘合剂相比，剥离强度值降低，而与等量的凝胶相无关。CTA和MM组合合成的所有粘合剂的剪切强度均较差。（C）2008 Elsevier Ltd.保留所有权利。
In this work, the effect of polymer molecular weight and crosslinking reactions on the end-use properties of the microsphere water-based acrylic pressure-sensitive adhesives (PSA) is presented. Polymer molecular weight and polymer microstructure were regulated using different chain transfer agent (CTA) concentrations and by addition of a diacrylic monomer (MM). The adhesion properties of the synthesized PSAs were characterized via measurements of tack, peel adhesion and shear strength. The results of experiments have shown that the kinetics of suspension polymerization is relatively independent on the amount of CTA and MM. The amount of gel phase in the adhesive was reduced with increasing amount of CTA agent, and gel phase amount may be considered as a function of polymer molecular weight. With a combination of CTA and MM was possible to regulate the amount of formed gel phase in the adhesive, as well sol phase molecular weight. All of the measured adhesion properties strongly depend oil molecular weight of the synthesized polymer and on the amount of gel phase. For adhesives synthesized solely with addition of CIA, tack decreased with lower polymer molecular weight and consecutively also with lower amount of gel phase. The same trend was also observed for peel strength measurements, whereas a cohesive failure was observed for adhesives with low amount of gel phase. A maximum value for tack and shear strength was observed at 80 wt% of gel phase. In case of syntheses with a combination of CTA and MM (amount of gel phase in range from 70 to 80 wt%), tack values were distributed in quite narrow range. On the other hand, peel strength values decreased in comparison with adhesives synthesized only with CTA, regardless to the equal amount of gel phase. Poor shear strength was observed for all adhesives synthesized by combination of CTA and MM. (C) 2008 Elsevier Ltd. All rights reserved.