氯乙烯(polyvinyl chloride,PVC)发泡板材使用低聚合度PVC 挤出发泡制得,PVC发泡板材受环境变化易沿着分子链受力方向发生链段的卷曲运动,导致板材发生收缩变形.重质碳酸钙(HCC)作为原料,聚乙烯醇(PVA)、单宁酸(TA)作为改性剂,制备了改性HCC.将其与PVC结合,制备了PVC发泡板材.利用红外光谱仪、差示扫描量热仪、扫描电子显微镜、维卡软化点测定仪、万能电子拉伸机对发泡板材进行表征,探讨了改性剂用量对发泡板材的尺寸稳定性的影响.研究结果表明,当TA含量是HCC的 3%时,PVC发泡板材的玻璃化温度是 88.1℃,维卡软化点温度是 75.21℃,PVC发泡板材具有优异的尺寸稳定性;同时泡孔结构稳定均一,具有最佳的拉伸强度,为 6.17 MPa.改性HCC颗粒分散性好,与PVC结合能力强,高尺寸稳定性的PVC发泡板材可以代替木材在家装板材的使用,对保护环境具有重要的意义.
Polyvinyl chloride(PVC)foam board is prepared by extrusion foaming of PVC with low polymerization degree,and the PVC foam board is prone to curling movement along the force direction of the molecular chain due to environmental changes,resulting in shrinkage and deformation of the board.Heavy calcium carbonate(HCC)was used as raw material,polyvinyl alcohol(PVA)and tannic acid(TA)were used as modifiers to prepare modified HCC.It was combined with PVC to prepare PVC foam sheets.Infrared spectrometer,differential scanning calorimeter,scanning electron microscope,Vicat softening point tester and universal electronic stretching machine were used to characterize the foamed board,and the effect of modifier dosage on the dimensional stability of the foamed board was discussed.The results show that when the TA content is 3%of HCC,the glass transition temperature of PVC foam board is 88.1℃,the temperature of Vicat softening point is 75.21℃,and the PVC foam board has excellent dimensional stability,and the cell structure is stable and uniform,and has the best tensile strength of 6.17 MPa.Modified HCC particles have good dispersion,strong binding ability with PVC,and high dimensional stability of PVC foam board can replace the use of wood in home decoration boards,which is of great significance to protect the environment.