Xiangjun Wang, Li Xinzhong, Lin Qi, Xia Jianrong, Xue Hanyu
Fujian Engineering and Research Center of New Chinese Lacquer Materials, Ocean College, Minjiang University Fuzhou Fujian 350108 P. R. China
Fujian Provincial University Engineering Research Center of Green Materials and Chemical Engineering, Minjiang University Fuzhou Fujian 350108 P. R. China.
RSC Adv. 2021 Oct 5;11(52):32565-32572. doi: 10.1039/d1ra05319a. eCollection 2021 Oct 4.
The need to improve the environmental friendliness and achieve the recycling of resins is an ongoing process for hot-melt adhesive technology. In this work, a new type of thermoreversible crosslinking hot-melt adhesive-based Diels Alder (DA) reaction was prepared. The critical idea was to efficiently initiate the esterification to yield furoic acid (FA)-grafted poly(vinyl alcohol) (PVA--FA), and then PVA--FA was mixed with ,'-(4,4'-methylenediphenyl)dimaleimide (MDI) to finally obtain the thermoreversible crosslinking adhesive (PVA--FA/MDI). The experimental results indicated that the reversibility of the DA reaction between the furan rings and the maleimide groups allowed PVA--FA/MDI to be dynamically crosslinked. It was able to crosslink at a temperature of 80 °C and decrosslink at 120 °C. Moreover, the performances of hot-melt adhesive were investigated. The PVA--FA/MDI had a better peeling strength (43.33 N mm), bond strength (11.84 MPa), and thermal conductivity (0.263 W m K) than PVA resins. The light-transmittance and haze value were 52.8% and 12.24‰, respectively. The PVA--FA/MDI resin could be reused more than two times.
提高热熔胶技术的环境友好性并实现树脂的回收利用是一个持续的过程。在这项工作中，制备了一种基于新型热可逆交联热熔胶的狄尔斯-阿尔德（DA）反应。关键思路是有效地引发酯化反应以生成糠酸（FA）接枝的聚乙烯醇（PVA-FA），然后将PVA-FA与双（4,4'-亚甲基二苯基）二马来酰亚胺（MDI）混合，最终得到热可逆交联粘合剂（PVA-FA/MDI）。实验结果表明，呋喃环与马来酰亚胺基团之间的DA反应的可逆性使PVA-FA/MDI能够动态交联。它能够在80°C下交联并在120°C下解交联。此外，还对热熔胶的性能进行了研究。PVA-FA/MDI具有比PVA树脂更好的剥离强度（43.33 N/mm）、粘结强度（11.84 MPa）和热导率（0.263 W/(m·K)）。透光率和雾度值分别为52.8%和12.24‰。PVA-FA/MDI树脂可以重复使用两次以上。
