本论文在pH值为2～2.5的条件下,以聚乙烯醇和甲醛为原料,在水溶液中发生缩醛反应制备,然后向胶中添加适量的尿素改性,制得聚乙烯醇缩甲醛胶粘剂.
At the circumstances of pH values at 2~2.5 and with the polyvinyl alcohol and formaldehyde as raw materials, thepolyvinyl formal adhesiveis prepared, as described in this paper, by aldolizing [them/the raw materials] in aqueous solution to prepare the glue and then adding adefined amount ofurea into the glue for modification (of its property).
通过实验研究了pH值、甲醛用量、反应时间、反应温度、水的加入量以及尿素的改性对聚乙烯醇缩甲醛胶粘剂性能的影响,合成性能较为良好的胶粘剂,得到了最佳的工艺条件（质量比%）：聚乙烯醇（12.5）、甲醛（4.5）、尿素（1.5）、蒸馏水（87.5）；反应温度为90℃,反应时间为3 h,pH值为2～2.5,粘度为7.6～8.0 Pas的聚乙烯醇缩甲醛胶粘剂.
The impact of pH value, dosage of formaldehyde, time of reaction, temperature of reaction, dosage of water added and urea modification on polyvinyl formal adhesive was researched with experiments, an adhesive of good/better performance was synthesized and the optimal process conditions (mass ratios %) was found/determined for preparation of the polyvinyl formal adhesive: polyvinyl alcohol (12.5), formaldehyde (4.5), urea (1.5), distilled water (87.5); the temperature of reaction is 90℃, time of reaction is 3 h, pH value is 2 ~ 2.5, the viscosity is 7.6 ~ 8.0 Pa s.
【注：本人翻译专业,非化工专业.专业术语若有出入,请更正】