聚羧酸减水剂相对分子质量及其分布对性能的影响

Impact of Polycarboxylic Acid Water Reducer's Relative Molecular Weight and Distribution on Its Performance

聚羧酸减水剂的性能不仅取决于所使用的原料,还与减水剂的重均相对分子质量和相对分子质量分布有关。影响相对分子质量及其分布的因素主要有聚醚双键保留率、生产工艺等。对比分析表明:聚醚双键保留率在一定范围内波动并不影响减水剂的使用性能;减水剂合成过程中的操作稳定性对其性能有很大影响;HPEG适合合成相对分子质量较小的减水剂,且减水效果良好;TPEG适合合成相对分子质量较大的减水剂,更有利于后期流动性的保持。

The performance of polycarboxylic acid water reducing agent depends on the raw materials, the weight average relative molecular weight and the distribution of molecular weight. The major factors that influence the molecular weight and its distribution are the double bonds retention rate of polyether and the production process. The results show that the fluctuation of polyether double bonds retention rate within a certain range does not affect the performance of water reducing agent, the stability of synthetic process has a great influence on the performance. HPEG is fit to synthesize the water reducing agent with low relative molecular weight and good performance, TPEG is fit to synthesize that with high relative molecular weight, and it is good at keeping the low slump loss of cement.