| 摘要: |
| 目的 为有效解决树脂胶黏剂粘度低以及降低胶合板中甲醛释放污染环境问题，使制备的树脂胶黏剂能更满足于室内用胶合板制品的要求。方法 以三聚氰胺(M)、乙二醛(G)和尿素(U)为原料制备三聚氰胺-乙二醛-尿素树脂胶黏剂(简称MGU)，用聚乙烯醇(PVA)改性正交实验优化出的MGU树脂胶黏剂(简称PVA/MGU)，并进行了胶合实验。结果 MGU树脂胶黏剂的最佳制备工艺:原料G、M、U物质的量的比为1∶0.18∶0.10，反应温度为65 ℃，反应时间为70 min，且采用质量分数为10%的PVA改性MGU树脂胶黏剂，压制的胶合板的胶合强度最佳，达到0.73 MPa，符合GB/T 17657—2013中Ⅱ类胶合板要求。PVA/MGU树脂胶黏剂的粘度为36.2 s，较MGU树脂胶黏剂提高了27%，游离甲醛的质量分数为0.011%，很大程度上满足了胶合板的使用要求，且游离醛含量较低，具有广阔的应用前景。结论 通过FT-TR分析发现，PVA与MGU树脂胶黏剂有化学键的结合;TG检测发现，PVA/MGU树脂胶黏剂的热稳定性和耐水性明显提高;DSC分析表明，PVA/MGU树脂胶黏剂的固化温度较未改性的有所降低。 |
| 关键词: 三聚氰胺-乙二醛-尿素树脂 胶黏剂 聚乙烯醇 胶合板 胶合强度 |
| DOI：10.19554/j.cnki.1001-3563.2022.05.005 |
| 分类号:TQ433 |
| 基金项目:国家自然科学基金(31972947，32171712);中央引导地方科技发展专项(202002003JC) |
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| Melamine-Glyoxal-Urea Resin Adhesive Modified by Polyvinyl Alcohol |
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QIN Ze-xiu1, LIU Ming-li1, LI Chun-feng1, CUI Xin-jie1, LI Yun2
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(1.Key Laboratory of Wood Material Science and Engineering, Beihua University, Jilin 132013, China;2.National Forestry and Grassland Administration Survey Planning and Design Institute, Beijing 100013, China)
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| Abstract: |
| The work aims to effectively solve the problem of low viscosity of resin adhesives and reduce the release of formaldehyde in plywood that pollutes the environment and to make the prepared resin adhesives better meet the requirements of indoor plywood products. The melamine-glyoxal-urea resin adhesive (MGU for short) was prepared with melamine (M), glyoxal (G) and urea (U), the MGU resin adhesive (PVA/MGU for short) was optimized through modification of orthogonal experiments with polyvinyl alcohol (PVA) and the gluing experiments were carried out. The best preparation process of MGU resin adhesive included the molar ratio of raw materials of G : M : U=1 : 0.18 : 0.10, the reaction temperature of 65 ℃, the reaction time of 70 min, and the PVA-modified MGU resin adhesive with a mass fraction of 10%. The pressed plywood had the best bonding strength of 0.73 MPa, which met the requirements of GB/T 17657—2013 Class II plywood. The viscosity of the PVA/MGU resin adhesive was 36.2 s, which was 27% higher than that of the MGU resin adhesive, and the content of free formaldehyde was 0.011%, which largely met the requirements of plywood use. In addition, due to the low content of free formaldehyde, the MGU resin adhesive had broad application prospects. According to the FT-TR analysis, PVA is chemically bonded to the MGU resin adhesive. From the TG test results, the thermal stability and water resistance of the PVA/MGU resin adhesive are significantly improved. According to the DSC analysis, the curing temperature of the PVA/MGU resin adhesive is reduced compared with that of the unmodified one. |
| Key words: melamine-glyoxal-urea resin adhesive polyvinyl alcohol plywood adhesive strength |
