缓释型引发剂的制备及其水泥基复合材料抗渗性能研究

Preparation of Sustained-release Initiator and Study on Impermeability of ECC

以丙三醇/聚吡咯为载体,包覆引发剂过硫酸钾,通过乳液聚合方法构筑了过硫酸钾/聚吡咯缓释型引发剂体系,然后将其与丙烯酸单体、 N,N-亚甲基双丙烯酰胺交联剂和水泥混合反应,制备出抗渗性水泥基复合材料。采用傅里叶红外光谱仪(FTIR)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)对缓释型引发剂体系的化学结构、微观结构、缓释效果进行了表征。结果表明:XRD显示过硫酸钾被聚吡咯包覆,且构筑的过硫酸钾/聚吡咯缓释型引发剂体系不改变过硫酸钾的化学结构。FTIR显示吡咯环的特征吸收峰出现在1296cm-1处,1059cm-1,691cm-1处,表明聚吡咯对过硫酸钾实现了包覆。随着过硫酸钾/聚吡咯缓释型引发剂掺量增加至18%,水泥基复合材料的抗压强度相对下降了3.90%,而抗渗性相对能提高了20.0%。

The potassium persulfate/polypyrrole sustained-release initiator system was constructed by emulsion polymerization with polypyrrole/glycerol as carrier that coated initiator potassium persulfate, the sustained-release initiator system was mixed with acrylic monomer, N, N’-methylene bisacrylamide cross-linking agent and cement to prepare impermeable ECC. The chemical structure, microstructure and sustained-release effect of the sustained-release initiator system were characterized by FTIR, SEM and XRD. Results show that potassium persulfate was coated by polypyrrole, and the potassium persulfate/polypyrrole sustained-release initiator system didn’t change the chemical structure of potassium persulfate in XRD.The characteristic peak of FTIR at 691 cm-1, 1059 cm-1, 1296 cm-1is the characteristic absorption peak of pyrrole ring, which indicates that polypyrrole has realized the coating of potassium persulfate. As the dosage of potassium persulfate/polypyrrole sustained-release initiator increases to 18%,the compressive strength of ECC decreased by 3.9%, and the impermeability increased by 20%.