改性粉煤灰对建筑胶粘剂固化性能的研究

Study on the Effect of Modified Fly Ash on the Curing Performance of Building Adhesives

为提升建筑胶粘剂的力学性能,同时减少粉煤灰对环境造成的污染,提出将不同改性粉煤灰作为无机填料制作胶粘剂。结果表明:胶粘剂的热流值随时间呈先增后减最终趋于0的变化特征,而固化度则是呈先增大后逐渐稳定的变化特征;掺入改性粉煤灰会导致胶粘剂的热流值和固化度略微降低,且改性粉煤灰的填充量越大,降低幅度越大;60℃下的完全固化度相比80℃时降低了25.6%,温度越高,完成完全固化的时间越短;粉煤灰胶粘剂的固化曲线符合Kamal模型,改性粉煤灰胶粘剂的总反应级高于未改性粉煤灰胶粘剂的总反应级,温度越高,改性粉煤灰填充量越大,总反应级越高;当增大改性粉煤灰填充量后,胶粘剂体系会逐渐由自催化化学控制向扩散控制转变,因而改性粉煤灰的填充量不宜过高(建议不超过30份)。

In order to improve the mechanical properties of building adhesives and reduce the environmental pollution caused by fly ash,it is proposed to use different modified fly ash as inorganic fillers to make adhesives.The results show that the heat flux value of the adhesive increases first,then decreases,and finally approaches 0 over time,while the curing degree shows a trend of increasing first and then gradually stabilizing;The addition of modified fly ash will slightly reduce the heat flow value and curing degree of the adhesive,and the larger the filling amount of modified fly ash,the greater the reduction;The complete curing degree at 60℃decreased by 25.6%compared to 80℃,and the higher the temperature,the shorter the time to complete the complete curing;The curing curve of the fly ash adhesive conforms to the Kamal model.The total reaction level of the modified fly ash adhesive is higher than that of the unmodified fly ash adhesive.The higher the temperature is,the greater the amount of modified fly ash is,and the higher the total reaction level is.However,when the amount of modified fly ash is increased,the adhesive system will gradually change from autocatalysis chemical control to diffusion control,so the amount of modified fly ash should not be too high.It is recommended not to exceed 30 phr.