硼改性酚醛树脂的合成及其模塑料力学性能研究

研究了硼酸加入量对所合成硼改性酚醛树脂性能的影响。通过红外光谱和热重等分析手段对硼改性酚醛树脂的结构和热性能进行表征，分别考察其在氮气和空气氛围下的残炭率，获知当苯酚、甲醛和硼酸之间的物质的量比为1∶1.4∶0.4时，硼改性酚醛树脂的残炭率最高，分别为67.82%和10.92%。此外，以硼改性酚醛树脂为基体树脂制备模塑料并考察其拉伸强度、弯曲强度和抗冲击强度等力学性能。综合考虑以上热性能和力学性能，确定苯酚、甲醛和硼酸之间的最佳物质的量比为1∶1.4∶0.3。最后，研究了添加不同种类和不同含量的填料对酚醛模塑料力学性能的影响。研究结果表明：以短玻璃纤维为填料时，酚醛模塑料的力学性能优于木粉和长玻璃纤维混合物填料；若使用木粉和长玻璃纤维混合物填料，当木粉与长玻璃纤维的质量比为1∶3时，酚醛模塑料的力学性能最佳。

Synthesis of Boron Modified Phenolic Resin and the Mechanic Performance of Its Molding Plastics

The effects of boracic acid dosage on the properties of modified phenolic resin were studied.The structure and thermal property of boron modified phenolic resin were characterized with infrared spectroscopy (IR) and thermogravimetric analyzer (TGA),respectively.It was shown that the residual carbon rate of the boron modified phenolic resin was 10.92% and 67.82%,respectively under the air and nitrogen conditions,when n(phenol)∶n(for-maldehyde)∶n(boron acid)= 1 ∶ 1.4 ∶ 0.4.Also,the mechanic properties,such as tensile,flexural and impact strength of the molding plastics prepared by boron modified phenolic resin were investigated.With the consideration of thermal and mechanic properties,the optimum molar ratio was obtained as n(phenol)∶n(formaldehyde)∶n(boracic acid)=1∶1.4∶0.3.Besides,the effects of filler kind and content for the molding plastics on its mechanic properties were investigated.It was shown that short glass fiber as filler was much better than long glass fiber and wood pow-der,and when wood powder and long glass fiber were used as the mixing filler,the optimum mass ratio of long glass fiber to wood powder was 3∶1.