低黏度高固含量聚醋酸乙烯酯乳液胶黏剂的制备及应用

Preparation and Application of Low Viscosity and High Solid Content Poly(vinyl Acetate)Emulsion Adhesive

聚醋酸乙烯酯(PVAc)具有固化速度快、初粘性好的优点,可作为胶黏剂或增稠剂应用于人造板工业。研究以醋酸乙烯酯(VAc)为单体、聚乙烯醇(PVA)为保护胶体,采用半连续乳液聚合法制备低黏度、高固含量聚醋酸乙烯酯乳液,并考察了PVA种类及其他聚合工艺因素对乳液性能的影响。结果表明:PVA种类对乳液性能影响较大。采用激光粒度分析仪、差示扫描量热仪(DSC)等对不同种类PVA合成的乳液进行表征表明:粒径随PVA醇解度增加而明显增大;PVA聚合度对乳液的玻璃化转变温度(Tg)影响较大。以PVA0599为保护胶体制备的PVAc乳液作为木材胶黏剂时,其拉伸剪切强度达8.62 MPa。

Poly(vinyl acetate)has been used as adhesive or thickener in wood-based panel industry because of its fast curing speed and excellent initial tack.In this work,VAc and PVA were used as monomer and protective colloid,respectively,to prepare low viscosity,high solid content PVAc emulsions by semi-continuous emulsion polymerization.The effect of PVA type and other polymerization process on the emulsion properties were explored.Among these factors,the type of PVA played an important role in the properties of the emulsion.The emulsions synthesized with different species of PVA were characterized by laser particle size analyzer and DSC,etc.The particle size result suggested that the particle size of the emulsion increased significantly with the PVA alcoholysis degree.DSC result showed that the Tg of the emulsion was greatly affected by the PVA polymerization degree.The PVAc emulsion prepared using PVA0599as protective colloid exhibited a lap shear strength of 8.62MPa was achieved when it was used as a wood adhesive.