分子质量调节剂对丙烯酸酯乳液压敏胶性能的影响

采用预乳化半连续聚合法,合成了丙烯酸酯乳液压敏胶。探讨了叔十二烷基硫醇、2,4-二苯基-4-甲基-1-戊烯、乙二醇以及异丙醇等分子质量调节剂对压敏胶聚合稳定性、黏度、初粘性、持粘性和180o剥离强度的影响。结果表明,叔十二烷基硫醇和异丙醇对压敏胶的性能影响较大,2,4-二苯基-4-甲基-1-戊烯和乙二醇的影响较小;随分子质量调节剂用量增大,压敏胶的初粘性增大,持粘性和180o剥离强度先增大后降低,黏度先降低后又增大;加入2,4-二苯基-4-甲基-1-戊烯和异丙醇的乳液压敏胶聚合稳定性随分子质量调节剂用量增大而变差,加入叔十二硫醇的乳液压敏胶的聚合稳定性则随用量增大先变差后又增强,而乙二醇则与之相反。

Effect of molecular weight modifier on performance of acrylic emulsion pressure-sensitive adhesives

The polyacrylate emulsion pressure sensitive adhesives （PSAs） were prepared via the pre-emulsified semi-continuous polymerization.The effects of tert-dodecyl mercaptan,2,4-diphenyl-4-methyl-1-pentene,ethylene glycol,and isopropyl alcohol on the polymerization stability,viscosity,tack,180o peeling strength,and holding power were discussed.The experiment results showed that tert-dodecyl mercaptan and isopropyl alcohol had a greater influence than 2,4-diphenyl-4-methyl-1-pentene and ethylene glycol on the performance of pressure sensitive adhesive.The results also showed that with increasing the amount of molecular weight modifier,the tack was increased,the holding power and 180o peeling strength first increased and then reduced,and the viscosity first reduced and then increased. The polymerization stability of the emulsion PSA reduced with the increase of amounts of 2,4-diphenyl-4-methyl-1-pentene and isopropyl alcohol,and with the increase of amount of tert-dodecyl mercaptan （TDM）,the polymerization stability reduced at beginning,and then increased,and ethylene glycol was just the opposite of TDM.