By conducting nuclear magnetic resonance (1H NMR) spectroscopy analysis on the four kinds of common poly-oxyethylene ether maromonomers,1H NMR spectrometric technique was developed to determine the type of polycarboxylate super-plasticizers(PC) rapidly and accurately. The ultrafiltration of polycarboxylate samples was carried out by ultrafiltration membrane with different molecular weight cutoffs. The collected polycarboxylate superplasticizer with different molecular weight was researched by 1H NMR spectroscopy. The results show that the molecular structure information of the PC-polyester was directly obtained by the analysis of the original 1H NMR without further ultrafiltration dialysis. However,that of the macromonomer of PC-polyether can only be accurately obtained by getting pure macromonomer after the pretreatment by 30 kD,10 kD and 3 kD ultrafiltration mem-brane. The method provides an important basis for resolving the molecular structure and molecular mass of different types of poly-carboxylate superplasticizers.%对常见的4种聚氧乙烯醚大单体进行了核磁共振氢谱(1H NMR)分析,并以此为依据建立了1H NMR技术,可快速、准确地鉴定聚羧酸减水剂的类型.采用不同截留分子质量的超滤膜对聚羧酸减水剂样品进行超滤,利用核磁共振氢谱对收集到不同分子质量的聚羧酸减水剂进行研究.结果表明,聚酯型聚羧酸减水剂大单体的分子结构信息通过原样的核磁谱图解析直接获得,无需进一步的超滤渗析;而聚醚型聚羧酸减水剂需要通过30 kD、10 kD和3 kD的超滤膜获得纯净的大单体,才可准确获得大单体的分子结构信息.该法为解析不同类型聚羧酸减水剂分子结构和分子质量提供重要的依据.
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