聚羧酸大分子的合成及其对石膏强度的影响

Synthesis of polycarboxylate macromolecules and the effect on strength of the gypsum

摘要:

以丙烯酸、丙烯酸甲酯、甲基丙烯磺酸钠及烯丙基聚氧乙烯醚为原料，过硫酸铵为引发剂，进行水相自由基共聚反应合成醚型聚羧酸大分子。合成产物对石膏具有明显缓凝作用。加有0.2% (以石膏质量计)的合成产物改性的石膏块，养护时间为24 h时，其抗折及抗压强度相比纯石膏的分别增加31.1%和32.6%，吸水率相比纯石膏的降低了9.1%。

Abstract:

Polycarboxylate macromolecule was synthesized using acrylic acid, methacrylate, sodium methallyl sulfonate and allyl polyoxyethylene ether，with ammonium persulphate used as initiator for radical aqueous solution polymerization. The polycarboxylate prolonged the gypsum plaster’s setting time. The plasters containing 0.2% polycarboxylate presented a increase of bending strength and compressive strength of 31.1% and 32.6% in 24 h, respectively. The water absorption rate of the modified plaster was 9.1% lower than that of pure plaster.