Cold-setting MUF resin adhesive prepared with concentrated fomaldehyde
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摘要: 为探究高质量分数甲醛对共缩聚合成三聚氰胺-尿素-甲醛树脂（MUF）性能的影响，以高质量分数甲醛（50%）为原料合成树脂（MUF-H），在自制混合固化剂作用下，通过常温（20 ℃左右）冷压制备胶合木，对比了高质量分数甲醛与普通甲醛合成树脂的物理力学性能，并借助动态热机械性能（DMA），红外光谱（FT-IR）和核磁共振（13C-NMR）等分析手段诠释两者间的差异。结果表明：相对于以普通甲醛制备的MUF树脂，以高质量分数甲醛替制备MUF-H树脂能有效提高树脂的固体含量和黏度，缩短固化时间，胶合木干状剪强度增幅为60%，耐水性能和剥离率测试皆能满足相关国家标准；动态热机械性能测试结果表明：高质量分数甲醛制备MUF-H树脂能大幅度增强树脂的弹性模量；核磁共振分析表明：以高质量分数甲醛合成的MUF-H树脂具有较高含量的三聚氰胺与尿素共缩聚产物亚甲基醚键，说明体系有较高的缩聚程度和交联度。图5表5参15
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关键词:
- 林业工程 /
- 高质量分数甲醛 /
- 共缩聚合成三聚氰胺-尿素-甲醛 /
- 常温固化 /
- 物理力学性能
Abstract: To research the influence of high formaldehyde concentrations on synthetic copolycondensation of melamine urea-formaldehyde （MUF） resin performance, resins from a high formaldehyde concentration （MUF-H） of 50% and standard concentration （MUF） of 37% were compared. Then glulam was prepared at room temperature （20 ℃） to test its physical and mechanical properties. Also, structural characteristics and thermal mechanical properties of resins were studied using 13C-NMR （nuclear magnetic resonance）, Fourier transform infrared （FT-IR） spectroscopy, and Dynamic Mechanical Analysis （DMA）. Results showed that the high formaldehyde concentrations enhanced solid content and viscosity of the MUF-H adhesive, shortened curing time, and improved shear strength for 60%. The DMA test results revealed that the MUF-H resin also greatly enhanced the adhesive elastic modulus. Additionally, the 13C-NMR analysis indicated that the methylene and ether bonds of MUF-H resin ware higher than MUF. Thus, the MUF-H system had a higher reaction rate and crosslinking degree which improved the mechanical properties of the resin.［Ch, 5 fig. 5 tab. 15 ref.］ -
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链接本文:
https://zlxb.zafu.edu.cn/article/doi/10.11833/j.issn.2095-0756.2016.02.016
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