纳米SiO2和CaCO3改性脲醛树脂甲醛含量及性能研究

采用质量分数1%硅烷偶联剂KH一570处理纳米SiO2和纳米CaCO3表面,通过间歇式超声波震荡法将纳米SiO2和纳米CaCO3加入脲醛树脂进行改性;研究了纳米SiO2和CaCO3用量对脲醛树脂游离甲醛、粘度、固化时间、拉伸剪切强度的影响.结果表明:纳米SiO2、CaCO3用量对相同F/U摩尔比脲醛树脂的性能有不同程度的影响.当纳米SiO2用量小于质量分数1.5%时,用量越大,游离甲醛含量越低,粘度越大,拉伸剪切强度越大,对固化时间影响不大,而纳米SiO2用量超过质量分数1.5%时,游离甲醛含量不再下降;随着纳米CaCO3的加入量的增加,游离甲醛含量也越低,粘度越大,拉伸剪切强度变化不大,树脂的固化时间延长,加入量大于质量分数7%时,树脂不能固化.因此纳米CaCO3加入量控制质量分数5%时,树脂性能最佳.

Study on Using Nanometer SiO2 and CaCO3 for the Free Formaldehyde Content of the UF Resin

Used nanometer SiO2 and nanometer CaCO3 which incorporated with 1 wt% KH-570 silane coupling agent to fill UF resin by discontinuous ultrasonic vibration to modify UF resin;Analyzed and discussed the effects of nanometer SiO2 and CaCO3 content on properties of the UF resin,such as free formaldehyde content,viscosity and stretch shearing strength.The results showed that nanometer SiO2 and nanometer CaCO3 content used in the same mole ratio of the F/U have the varying degree influence compared to the UF resin performance.When the content of nano-SiO2 was below 1.5 wt%,the content of free formaldehyde decreased,viscosity and stretch shearing strength of the resin increased with the nano-SiO2 added,which had little contribution to the curing time.However,the content of free formaldehyde was not decreased when the content of nano-SiO2 was over 1.5 wt%;Free formaldehyde was decreased,while viscosity was increased as the nanometer calcium carbonate was added.Although calcium carbonate had little influence on stretch shearing strength,it delayed the curing time of resin.When the content of calcium carbonate is more than 7 wt%,the resin cannot solidify.Therefore,when the content of calcium carbonate supposed to be controlled about 5wt%,the properties of the resin was best.