酚醛树脂改性脱硫石膏的热压工艺与耐水性能

摘要

研究了热压成型工艺对酚醛树脂改性脱硫石膏复合材料(简称复合材料)力学性能的影响,以及酚醛树脂对复合材料耐水性能的影响.采用X射线衍射仪(XRD)、热重分析仪(DTA)、扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)以及等温量热仪研究了酚醛树脂改性脱硫石膏的微观结构及水化机理.结果表明:复合材料抗折强度最佳热压成型工艺为热压压力8 MPa,热压温度160℃,热压时间120 s,抗压强度最佳热压成型工艺为热压压力8 MPa,热压温度180℃,热压时间75 s;当酚醛树脂掺量(质量分数,下同)为1.0％,硅烷偶联剂掺量为0.3％且膨胀剂掺量为3.0％时,复合材料2,24 h的吸水率分别为0.58％和1.07％;酚醛树脂具有填充孔隙、密实体系和提高复合材料耐水性能的作用.%Mechanical property and water resistance properties of desulphurization gypsum were improved by phenolic resin using the hot pressing process.X-ray diffraction(XRD),thermo-gravimetric analyzer(DTA),scanning electron microscopy(SEM),Fourier transform infrared spectrometer(FTIR) and isothermal calorimeter were employed to study microstructure and hydration mechanism of composite.The results show that optimal parameter in hot-pressing process for flexural strength is 8 MPa,160 ℃ and 120 s,optimal parameter in hot-pressing process for compressive strength is 8 MPa,180 ℃ and 75 s;when content of phenolic resin,silane coupling agent and expansive agent are 1.0 ％,0.3 ％ and 3.0 ％ (by mass) respectively,water absorption (2 h) and water absorption(24 h) are 0.58％ and 1.07％ respectively.Phenolic resin play the role to fill pores and enhance dense ability and water resistance properties during the hydration process.