交联型两性聚丙烯酸酯的制备及对纸张性能的影响

以聚乙烯醇（PVA）为高分子胶体稳定剂,甲基丙烯酸缩水甘油酯（GMA）为交联剂,丙烯酰胺（AM）、丙烯酸（AA）、丙烯腈（AN）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）为共聚单体,通过无皂乳液共聚制备了交联型两性聚丙烯酸酯表面施胶剂。对阳离子基单体和交联性单体的用量、合成工艺条件等对纸张增强效果的影响进行了探讨。确定了较佳的合成条件：种子聚合法,w（PVA）=3%-4%,w（DMC）=2%-2.5%,w（GMA）=0.7%,反应温度85℃,反应时间5 h。通过差示扫描量热仪（DSC）、扫描电子显微镜（SEM）和粒度分布分析仪对乳液和纸张性能进行了检测与表征。实验证明,在pH值78条件下,以2%的聚合物乳液进行表面施胶时,可使环压指数、耐破度、抗张指数分别达到16.6 N·m/g、440 kPa、40.6 N·m/g,耐折度10次,与空白样相比均可提高30%以上。

Preparation of Crosslinking Amphoteric Polyacrylic Copolymer Microemulsion and Its Surface Sizing Mechanism

Crosslinking amphoteric polyacrylic microemulsion was prepared by the emulsifier-free copolymerizationof acrylic acid ( AA) /acryl amide (AM) /vinyl cyanide (AN) / methacryloxyethyl trimethylammonium chloride (DMC) , using GMA as crosslinking agent,polyvinyl alcohol (PVA) as deflocculating agent. According to the application results, the optimum reaction conditions were described as below; seed polymerization, temperature 85 ?, reaction time 5 h, w(PVA) = 3% ~4%,w(DMC) = 2% -2.5%, w(GMA) =0.7%. And the dosages of cationic monomers, crosslinking monomers and the process condition were discussed in detail. The properties of the emulsion and the paper treated with the copolymer surface sizing agent were characterized by DSC, SEM and particlesize analyzer. Results showed that ring rush index, bursting strength, tensile index and folding endurance of the paper can increase about 30% when the cross-linked amphoteric acrylic emulsion of 2% dosage is used as the surface sizing agent.