丁氧基封端聚醚高效减水剂的合成及性能

通过酯交换合成了不同分子量的丁氧基聚氧乙烯甲基丙烯酸酯(BPEGMA),并通过水溶液调节共聚合方法制备了丁氧基聚氧乙烯甲基丙烯酸酯/丙烯酸/甲基丙烯酸/2-丙烯酰胺基-2-甲基丙磺酸(BPEGMA/AA/MAA/AMPS)多元共聚物。用红外光谱(FT-IR)表征了共聚物的分子结构,详细研究了聚乙二醇(PEG)支链长度、BPEGMA用量、AMPS用量和AA/MAA摩尔比等因素对其分散性能的影响。研究表明,该共聚物对水泥具有良好的分散性及分散保持性能,掺量为0.3%,水灰比为0.29时,水泥净浆流动度可达335mm,120min内坍落度基本不变。

Polycarboxylic Superplasticizer with Butoxy-Terminated Polyether Branched-Chain and Its Properties

Different molecular weight of butoxy poly(ethylene oxide) methacrylate(BPEGMA) was prepared by ester exchange reaction and BPEGMA/AA/MAA/AMPS copolymer were synthesized from BPEGMA,acrylic acid(AA),methacrylic acid(MAA) and 2-acrylamido-2-methyl propane sulfonic (AMPS) through aqueous telomerization.The structures were characterized by Fourier transform infrared spectrum(FT-IR).The influences of the poly(ethylene glycol)(PEG) length,the dosage of BPEGMA,AMPS and AA/MAA molar ratio on the fluidity of cement paste were investigated in details.The results indicate that the comb-like copolymer exhibits high dispersing and flowing retention properties.At this copolymer dosage of 0.3% and water-cement ratio of 0.29,the fluidity of cement grout can attain as high as 335 mm and there is no change on the slump constant within 120 minutes.