非水介质中羧基酯化聚乙烯醇的合成及其在表面施胶中的增强应用

Synthesis of Carboxylic Esterified Polyvinyl Alcohol in Non-aqueous Medium and Its Enhancement Application in Surface Sizing

中文关键词:  非水介质  水性  羧基酯化  马来酸酐  表面施胶剂  物理性能  油墨附着力

Key Words:non-aqueous media  waterborne  carboxylic esterification  maleic anhydride  surface sizing agent  physical property  ink adhesion

中文摘要:

      以N-甲基-2-吡咯烷酮（NMP）为溶剂，四丁基溴化铵为催化剂，通过马来酸酐（MAH）对低醇解度的聚乙烯醇（PVA0588）进行改性，得到羧基酯化聚乙烯醇（NWMPA）；通过FT-IR、¹H-NMR等手段对NWMPA的结构进行表征；分析了PVA0588与MAH质量比对NWMPA羧基含量及其分散液稳定性等性能的影响；最后探讨了PVA1799与NWMPA复配的用量对纸张物理性能的影响。结果表明，当m（PVA0588）∶m（MAH）=2∶1时，NWMPA-3分散液相对稳定，平均粒径为368 nm、分散性指数为0.418、稳定指数为3.802，碘值和羧基含量分别达到28.55 g/（100 g）和49.65 mmol/L；与原纸相比，3.0 wt% NWMPA-3与4.0 wt% PVA1799复配施胶后纸张的施胶度、干抗张指数、湿抗张指数、耐折度分别提高了1246.5%、33.6%、50.6%、243.8%；与市售施胶剂相比，PVA1799/NWMPA-3复配施胶剂的储存期更长，对纸张油墨附着力等级可达到合格等级4B。

Abstract:

      Carboxyl esterified polyvinyl alcohol （NWMPA）， a surface sizing agent， was synthsized by modifying low-alcoholysis polyvinyl alcohol （PVA0588） with maleic anhydride （MAH） using N-methyl-2-pyrrolidone （NMP） as solvent and tetrabutylammo-nium bromide as catalyst in this study. The structure of NWMPA was characterized by FT-IR and ¹H-NMR， the effects of mass ratio of PVA0588 to MAH on the carboxyl content and the stability of NWMPA dispersion were analyzed， and the effects of dosage of PVA1799 and NWMPA on the physical properties of the surface-sized paper were discussed. The results showed that when m（PVA0588）∶m（MAH）=2∶1， the NWMPA-3 dispersion was stable with average particle size of 368 nm， dispersion index of 0.418， stability index of 3.802， and iodine value and carboxyl content of 28.55 g/（100 g） and 49.65 mmol/L， respectively. Compared with the base paper， the sizing degree， dry tensile index， wet tensile index， and folding strength of the paper sized with 3.0 wt% NWMPA-3 and 4.0 wt% PVA1799 increased by 1246.5%， 33.6%， 50.6%， and 243.8%， respectively. Compared with the commercial sizing agent， the storage period of time of PVA1799/NWMPA-3 compound sizing agent is longer and its paper ink adhesion grade is evaluated as qualified grade 4B.