改性剂的酸性对酚醛树脂的影响

The effect of the additive acidity on phenolic resins

以3种不同酸性的物质—氢氧化铝、硼酸和磷酸作为改性剂,通过熔融共混法对酚醛树脂进行改性,并对样品进行了红外、热失重和机械性能等测试。结果表明,只有具有酸性的物质(硼酸与磷酸)对酚醛树脂的性能有较大提高。比如硼酸改性酚醛树脂的热稳定性和冲击强度分别在硼酸含量为10%(wt,下同)和4%时获得极大值;而酸性更强的磷酸作为改性剂时,相应的极大值位置在磷酸含量更低时就可获得,分别在4%和2%。此外,3种改性剂的使用,都提高了酚醛树脂的硬度。这些表明了改性剂的酸性对于酚醛树脂性能有重要的影响。

Three additives with different acidites,namely Al（OH）3,H3BO3 and H3PO5,were used to modify phenolic resin（PR） via melt mixing.Samples were characterized by FTIR,TGA and mechanical properties testes.Characterization results showed that only acidic reagents（H3BO3 and H3PO5） improved the properties of modified PRs.For example,the thermal stability and impact strength of H3BO3 modified PRs reached the top at 10% and 4% of H3BO3 content,respectively;while as H3PO5 was used as reagent,the response H3PO5 contents were 4% and 2%.Besides,all modified PRs had higher hardness than pure PR.All these showed the obviously effect of the acidity of reagent to the modified PRs.