以萘硼酸、苯酚和甲醛水溶液为原料,盐酸和二水合草酸为催化剂,制备了萘硼酸酚醛树脂(BPF)。通过傅里叶变换红外光谱仪、核磁共振分析仪对其进行结构表征,利用差示扫描量热仪考察了升温速率对BPF特征温度的影响,通过热重分析仪、热变形维卡软化点测定仪、电子万能试验机测试了BPF的热性能、软化点和力学性能。结果表明:硼元素以化学键的形式接入到酚醛树脂结构当中;BPF凝胶化温度T_gel为113.3℃、固化温度T_cure为142.2℃、后处理温度T_treat为157.6℃;当萘硼酸含量为10%(wt,质量分数,下同)时,BPF的热分解峰值温度、800℃残炭率比未改性酚醛树脂分别提高了17.39%和28.79%,软化温度提高了16.79%;萘硼酸含量为10%时,BPF拉伸剪切强度、弯曲强度比未改性酚醛树脂分别提高了262.5%和128.3%;萘硼酸含量为6%时,BPF冲击强度提升最大,为2.5kJ/m²。

Naphthyl boric acid phenolic formaldehyde resin (BPF) was prepared using naphthyl boronic acid,phenol and formaldehyde solution as raw materials,and hydrochloric acid and oxalic acid dihydrate as catalysts.The structure of BPF was characterized by Fourier transform infrared spectrometer and nuclear magnetic resonance analyzer.The effect of heating rate on the characteristic temperature of BPF was investigated by differential scanning calorimeter.The thermal properties,softening point and mechanical properties of BPF were tested by thermogravimetric analyzer,thermal deformation Vicat softening point tester and electronic universal testing machine.The results showed that boron was inserted into the phenolic resin structure in the form of chemical bond.BPF gelation temperature (T_gel) was 113.3℃,curing temperature (T_cure) was 142.2℃,and post-treatment temperature (T_treat) was 157.6℃.When the content of naphthalene boronic acid (wt,mass fraction,the same below) was 10%,the peak thermal decomposition temperature of BPF and the residual carbon rate at 800℃ were 17.39% and 28.79% higher than those of unmodified phenolic resin,respectively,and the softening point increased by 16.79%.Simultaneously,the tensile shear strength and bending strength of BPF were 262.5% and 128.3% higher than those of unmodified PF,respectively.When the content of naphthalene boronic acid was 6%,BPF exhibited the highest increase in impact strength,reaching 2.5kJ/m².