N-羟甲基丙烯酰胺自交联乳液的合成及其交联反应的研究

Synthesis and reaction of NMA self crosslinking emulsion

N-羟甲基丙烯酰胺(NMA)自交联丙烯酸乳液的交联固化条件目前有不同的报道。以NMA为交联单体,设计合成了一种自交联的苯丙乳液,研究了NMA用量、链转移剂十二硫醇,以及热处理条件等因素对乳液及其乳胶膜性能的影响。结果表明:部分NMA在乳液聚合过程中就可以通过链转移反应而生成交联结构;一定用量的十二硫醇可以有效阻止聚合过程中NMA之间的交联反应;NMA乳液为高温自交联体系,在室温下基本不发生交联反应,110℃以上才能有效交联。对乳胶膜性能的研究表明,随着热处理温度的升高,乳胶膜的交联度、接触角和拉伸强度均相应增大,而断裂伸长率降低。

At present,there are different reports on the crosslinking curing conditions of N-methylol acrylamide(NMA)self-crosslinking acrylate emulsions.A self-crosslinking styrene-acrylic emulsion was prepared with NMA as crosslinking agent.The effects of NMA dosage,dodecanethiol and heat treatment conditions on the properties of emulsion and latex film were studied.It was found that partial NMA could form crosslinked structures during the polymerization process.A certain amount of dodecanethiol can effectively prevent the occurrence of internal crosslinking reaction between NMA during polymerization.For this emulsion there was no crosslinking reaction at room temperature but crosslinking reaction can occur effectively above 110℃.Study on performance of the latex films indicated that,the crosslinking degree,the contact angle and tensile strength increased,while tensile elongation decreased with increase of the heat treatment temperature.