Park Hee-Woong, Seo Hyun-Su, Kwon Kiok, Lee Jung-Hyun, Shin Seunghan
Green Chemistry & Materials Group, Korea Institute of Industrial Technology (KITECH), Cheonan 31056, Korea.
Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Korea.
Polymers (Basel). 2020 Oct 19;12(10):2410. doi: 10.3390/polym12102410.
To improve the heat resistance of acrylic-based pressure-sensitive adhesive (PSA), silicone-block-containing acrylic PSAs (SPSAs) were synthesized using a polydimethylsiloxane (PDMS)-based macro-azo-initiator (MAI). To evaluate the heat resistance of the PSA films, the probe tack and 90° peel strength were measured at different temperatures. The acrylic PSA showed that its tack curves changed from balanced debonding at 25 °C to cohesive debonding at 50 °C and exhibited a sharp decrease. However, in the case of SPSA containing 20 wt% MAI (MAI20), the balanced debonding was maintained at 75 °C, and its tack value hardly changed with temperature. As the MAI content increased, the peel strength at 25 °C decreased due to the microphase separation between PDMS- and acryl-blocks in SPSA, but the shear adhesion failure temperature (SAFT) increased almost linearly from 41.3 to 122.8 °C. Unlike stainless steel substrate, SPSA showed improved peel strength on a polypropylene substrate due to its low surface energy caused by PDMS block. Owing to the addition of 20 wt% silicone-urethane dimethacrylate oligomer and 200 mJ/cm UV irradiation dose, MAI20 showed significantly increased 90° peel strength at 25 °C (548.3 vs. 322.4 gf/25 mm for pristine MAI20). Its heat resistance under shear stress assessed by shear adhesion failure test (SAFT) exhibited raising in failure temperature to 177.3 °C when compared to non-irradiated sample.
为提高丙烯酸类压敏胶粘剂（PSA）的耐热性，使用基于聚二甲基硅氧烷（PDMS）的大分子偶氮引发剂（MAI）合成了含硅氧烷嵌段的丙烯酸类PSA（SPSA）。为评估PSA薄膜的耐热性，在不同温度下测量了探针粘性和90°剥离强度。丙烯酸类PSA显示其粘性曲线从25℃时的平衡脱粘变为50℃时的内聚脱粘，并呈现出急剧下降。然而，对于含有20 wt% MAI（MAI20）的SPSA，平衡脱粘在75℃时得以保持，其粘性值几乎不随温度变化。随着MAI含量的增加，由于SPSA中PDMS嵌段和丙烯酸嵌段之间的微相分离，25℃时的剥离强度降低，但剪切粘附失效温度（SAFT）从41.3℃几乎线性增加到122.8℃。与不锈钢基材不同，由于PDMS嵌段导致的低表面能，SPSA在聚丙烯基材上显示出提高的剥离强度。由于添加了20 wt%的硅氧烷 - 聚氨酯二甲基丙烯酸酯低聚物和200 mJ/cm的紫外线辐照剂量，MAI20在25℃时的90°剥离强度显著增加（原始MAI20为322.4 gf/25 mm，MAI20为548.3 gf/25 mm）。通过剪切粘附失效试验（SAFT）评估，其在剪切应力下的耐热性显示，与未辐照样品相比，失效温度提高到了177.3℃。
