红外光谱与热重分析法研究腐植酸改性脲醛树脂

将腐植酸(HA)进行羟甲基化改性,然后按照m(HA羟甲基化溶液)∶m脲醛树脂(UF)]=1∶4比例将两者混合均匀,制得腐植酸-脲醛树脂(HUF)。采用红外光谱(FT-IR)、热重分析(TGA)及差示扫描量热(DSC)法等对UF和HUF的结构、热稳定性及玻璃化转变温度(Tg)等进行表征。结果表明:HUF与UF的FT-IR曲线基本相同,前者的FT-IR特征峰均有不同程度增强,热失重峰向高温区移动,说明HUF既保留了UF的原有结构,又具有较强的耐热性;当w(改性HA)=5%～30%时,HUF胶粘剂的胶接强度相对较大;与未改性UF相比,HUF价格更低(节约350元/t)、更环保(甲醛释放量达到GB 18 580-2001标准中E1级指标要求),故HUF具有较强的市场竞争力和良好的应用前景。

Study on humic acid modified urea formaldehyde resin by infrared spectroscopy and thermogravimetry

A humic acid-urea formaldehyde resin(HUF) was prepared by the mixture method between humic acid(HA) solution modified by hydroxymethylation and urea formaldehyde resin(UF) according to mass ratio at 1∶4.The structure,thermal stability and glass transition temperature(Tg) for UF or HUF were characterized by infrared spectroscopy(FT-IR),thermogravimetry(TGA) and differential scanning calorimetry(DSC) methods.The results showed that the FT-IR curves for UF or HUF were almost same.The HUF’s FT-IR characteristic peaks were all enhanced,and its thermal weight loss peak was moved to high temperature,so the HUF had both original structure of UF and strong heat resistance.The bonding strength of HUF adhesive was more than that of unmodified UF adhesive when mass fraction of modified HA was 5%-30%.The HUF had strong competitive power in market and well application prospect because the prices of HUF were RMB 350 yuan/t less than that of unmodified UF,the environmental friendly of HUF was better than that of unmodified UF because the formaldehyde releasing contents of HUF could meet requirement of E1 level in GB 18 580-2001 standard.