采用单因素试验、VPO（vapour pressure osmometer)测量和特性粘度分析的方法，对影响强酸下合成的脲醛树脂胶粘剂（UFRA）胶合强度的因素进行了研究。得出了强酸条件下合成UFRA提高胶合强度的合理工艺。研究发现，合成过程中甲醛与尿素不同物质的量比与胶合强度关系密切。由于UFRA的相对平均摩尔质量随甲醛与第1次尿素物质的量比（nF/nU1)和甲醛与第2次尿素物质的量比（nF/nU2)变化，导致胶合强度发生变化；在nF/nU1=2.6、nF/nU2=1.5、甲醛与尿素总物质的量比为1．2条件下合成出了胶合强度值为1.19MPa而游离甲醛含量w仅为0.09^的UFRA。
The factors of influencing interal-bonding strength when using urea-formaldehyde resin adhesives (UFRA) synthesized in strong acid were studied with single factor tests, viscosity characteristics analysis and vapour pressure osmometer measuring. The optimal technological procedure for synthesizing UFRA in strong acid to get enhanced bond strength was worked out. It was found that strength-bond was closely related to the molar ratio between formaldehyde and urea in technology. The bond strength was improved and average molar quality rose when the molar ratio ( n F/ n U 1 ) between formaldehyde (F) to first-urea (U 1) was decreased. The UFRA was made so that bond strength was up to 1 19 MPa and free formaldehyde content was only 0 09% when n F/ n U 1 was 2 6, the molar ratio ( n F/ n U 2 ) between formaldehyde and urea (U 2)(added urea in strong acid and weak base) 1.5 and the molar ratio between formaldehyde and urea (total urea) 1.2.