PVC木塑发泡材料性能的研究

Study on properties of PVC-based wood-plastic composite foamed materials

研究了PVC树脂基本性能(聚合度、分子质量分布、表观密度)、助剂(发泡剂、发泡调节剂)、木粉及加工工艺(加工温度、挤出速度)对PVC木塑发泡材料性能的影响,并进行了工业化加工试验。结果表明:PVC树脂聚合度越高,发泡材料泡孔壁厚越大,发泡及加工都变得较为困难,适宜的聚合度为650~700;PVC树脂分子质量分布变宽,则发泡材料的密度增大,泡孔数量减少,泡孔增大,泡壁增厚,有串泡现象,适宜的分子质量分布指数为1.9~2.0;表观密度越高,机身压力越大,发泡材料泡孔数量越多,泡孔结构越均匀,适宜的表观密度为0.57~0.60 m L/g。对于S-700型PVC树脂而言,发泡剂AD C与助发泡剂Z n O的适宜质量比为1∶0.1,且二者的总用量以1.0份为宜;发泡调节剂ZB-530的适宜用量为8份;适宜的加工温度为185℃,适宜的挤出速度为20 r/min。宜采用硅烷偶联剂对木粉进行表面改性,发泡剂、发泡调节剂的用量应随着木粉用量的变化而调整。工业化加工试验结果表明:根据制品及生产设备的不同对试验得出的配方和加工工艺进行调整后,可顺利生产出质量优良的产品。

The effects of basic properties （polymerization degree, molecular weight distribution and apparent density）of PVC resins, additives （foaming agent and foaming control agent） , wood flour and processing technology （processing temperature, extrusion speed） on the properties of PVC-based wood-plastic composite foamed materials were studied. The industrial processing test was carried out. The results showed that the higher the polymerization degree of PVC resins, the larger the cell wall thickness of foamed materials, the more difficult the foaming and the processing were. The suitable polymerization degree was 650 -700. With the widening of molecular mass distribution of PVC resins, the density of foamed materials increased, the number of cells reduced, the cell wall thickness increased, and consecutive cells occurred. The suitable molecular mass distribution index was 1.9 -2.0. The higher the apparent density, the greater the extruder pressure, the more the number of cells of foamed materials, the more uniform the cell structure was. The suitable apparent density was 0.57 -0.60 mL/g. For PVC resin S -700, the suitable mass.ratio of foaming agent ADC and secondary foaming agent ZnO was 1 ： 0.1. Total amount of the two agents was 1 phr. The suitable amount of foaming control agent ZB -530 was 8 phr. The suitable processing temperature was 185 ℃, and the suitable extrusion speed was 20 r/min. The wood flour should be modified by silane coupling agent. The amounts of foaming agent and foaming control agent should be adjusted with the change of the amount of wood flour. Industrial processing test results showed that after the obtained formula and processing technology were adjusted according to different products and production equipment, the products with good quality could be successfully produced.