聚醚改性聚天冬氨酸减水剂的制备及其性能

Synthesis and Properties of Polyether-Modified Poly(aspartic acid) Superplasticizer

以聚琥珀酰亚胺(PSI)和端氨基聚醚(M2005)为原料,合成了聚醚改性聚天冬氨酸减水剂(PEMPASP),采用FTIR对PEMPASP进行了结构表征,考察了不同减水剂及其用量对水泥净浆流动度和胶砂强度的影响;通过对TOC、Zeta电位、XRD以及TG-DSC分析,分析了PEMPASP减水剂的作用机理。结果表明:当n(PSI)∶n(M2005)=1∶0.14、PEMPASP掺量为水泥质量的0.35%时,水泥的净浆比掺加聚天冬氨酸(PASP)的水泥净浆流动度提高了189%,在PEMPASP质量分数为水泥的0.25%时,水泥胶砂抗折强度比空白水泥增长了15.6%,比含有PASP的水泥胶砂增长了17%;由于在PASP分子链上引入长侧链聚醚链,改变了减水剂分子上的电荷密度和侧链结构,影响了减水剂对水泥颗粒的静电作用和位阻作用,进而改善了吸附、分散以及水泥的水化作用,提高了减水剂的综合性能。

Polyether-modified poly(aspartic acid) superplasticizer(PEMPASP) was synthesized by using polysuccinimide(PSI) and polyetheramine(M2005) as materials and characterized by FTIR. The effects of different superplasticizers and their dosage on the fluidity and flexural strength of cement pastes were discussed. The mechanism of PEMPASP superplasticizer was studied by TOC, Zeta potential, XRD and TG-DSC. The results showed that when the molar ratio of PSI to M2005 was 1∶0.14, the prepared superplasticizer exhibited good performance. The fluidity of cement paste containing 0.35% PEMPASP was increased by 189% compared with that of cement paste containing polyaspartic acid(PASP). When the mass fraction of this PEMPASP was 0.25% of cement, the flexural strength of cement mortar was increased by 15.6% compared with that of blank cement and 17% higher than that of cement mortar containing PASP. The introduction of long-chain polyether can change the charge density and side chain structure of superplasticizer, which affects the electrostatic effect and steric hindrance of superplasticizer on the cement particles. Thus, the adsorption, dispersion and the hydration of cement are improved, and the comprehensive performance of superplasticizeris improved.