干燥条件对缓释型粉体聚羧酸减水剂性能的影响

Effect of Drying Condition on Properties of Slow-Release Powder Polycarboxylate Superplasticizers

摘要:

对含有不同缓释功能基团的液体聚羧酸减水剂进行干燥处理，得到了相应的缓释型粉体聚羧酸减水剂，通过净浆流动度经时损失、红外光谱等方法研究了不同干燥条件对于缓释型粉体聚羧酸减水剂的性能影响规律及其作用机理.结果表明：干燥温度是影响缓释型粉体聚羧酸减水剂产物性能的主要因素；由于不同缓释型聚羧酸减水剂含有的缓释功能基团的水解活性不同，其可耐受的最高干燥温度不同；高真空干燥条件及调节液体减水剂pH值至8.5以上均有利于改善干燥产物的性能.

Abstract:

The slow-release powder polycarboxylate superplasticizers （PCEs） containing different slow-release functional groups were obtained by drying the corresponding liquid PCEs at different conditions. The effect of drying condition on the properties of slow-release powder PCE and its mechanism were studied by fluidity retention of cement paste， Fourier transform infrared spectroscopy（FTIR）， etc. The results show that drying temperature is the main factor affecting the properties of the slow-release powder PCE， and the maximum drying temperature of different kinds of slow-release PCEs depends on the hydrolysis reactivities of slow-release functional groups in their molecules. The high vacuum drying condition and the adjustment of the pH value of liquid PCE above 8.5 are beneficial to improve the properties of the dried products.