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以聚乙烯醇(PVA)和丁烯醛为主要原料,合成了聚乙烯醇缩丁烯醛(PVBE)。讨论了反应时间、丁烯醛用量、HCl含量和PVA浓度等因素对PVBE黏度的影响。结果表明:200 mL PVA(质量浓度大于5%)溶液中加入0.75～1.5 mL的HCl,当丁烯醛用量(ρ)在0.15～0.25之间,通过调节以上因素,室温反应120～216 h可制得适宜黏度的PVBE水溶液;同时介绍了PVBE中去除残余醛的两种方法;最后研究了低残余醛PVBE作为增稠剂、保护胶体在聚醋酸乙烯(PVAc)乳液中的应用。
With polyvinyl alcohol (PVA) and crotonaldehyde as the main raw material, polyvinyl butyral (PVBE) was synthesized. The effects of reaction time, the amount of crotonaldehyde, the content of HCl and the concentration of PVA on the viscosity of PVBE were discussed. The results showed that 0.75-1.5 mL HCl was added to 200 mL PVA solution (mass concentration> 5%). When the amount of crotonaldehyde (ρ) was between 0.15 and 0.25, the reaction temperature was 120-216 h PVBE aqueous solution with proper viscosity was prepared. Two methods for removing residual aldehydes in PVBE were also introduced. Finally, the application of low residual PVBE as thickener and protective colloid in polyvinyl acetate (PVAc) emulsion was studied.