磷石膏/聚丙烯复合材料制备

Preparation of phosphogypsum/polypropylene composites

为了将磷石膏资源化利用,将40℃下烘干处理的磷石膏与聚丙烯颗粒混合后,再添加少量液体石蜡,经过热压成型制备了磷石膏/聚丙烯复合材料.在所制备复合材料中磷石膏至少占50%以上,增大了磷石膏的消耗量;并且在材料制备工艺中磷石膏预处理方法简单易行,增加了整个制备工艺的可行性.结果表明,磷石膏/聚丙烯复合材料密度随原料中磷石膏掺量增加而增大,磷石膏掺量为50%时,视密度每立方厘米1.089克;磷石膏掺量为80%时,视密度每立方厘米1.405克.磷石膏/聚丙烯复合材料的弯曲强度随着磷石膏掺量增加而增大,磷石膏掺量为80%时弯曲强度可达14.3MPa.但所制备磷石膏/聚丙烯复合材料样品的脆性较大,拉伸强度较低,与磷石膏的掺量无明显的相关性,磷石膏掺量为70%时拉伸强度1.7MPa,适用于要求塑性变形小的场合.所制备复合材料还有另一显著特点是耐水性很好,无论原料配比如何其软化系数均在1.0以上,从而克服了一般石膏制品耐水性差的缺点.最佳成型制度为成型温度160℃,成型压力15MPa.

To recycle utilization the phosphogypsum, phosphogypsum dried under temperature of 40 ℃ was mixed with ploypropylene powders, then a small amount of liquid parpffin was added. The phosphogypsum/polypropylene composite materials were prepared by hot-press. The proportion of phosphogypsum in composite materials was at least 50%, so the consumption of the solid waste was increased. The research results show the density increases with the proportion of phosphogypsum increasing, the apparent density is 1. 089 g per cubic centimetre while the ratio of phosphogypsum is 50% ; the apparent density is 1. 405 g per cubic centimetre while the ratio of phosphogypsum is 80% the bend strength of composite samples increases with the proportion of phosphogypsum increasing, the maximum of bend strength is 14.3 MPa while the ratio of phosphogypsum is 80%. But the brittleness of the samples prepared is large. The tensile strength is low and has no significant correlation with the content of phosphogypsum The tensile strength is 1.7 MPa while the ratio of phosphogypsum is 70 %. It suits the occation when the plastic deformation is small. Another obvious advantage of the composite prepared is that the water resistance of samples is very good, no matter what the raw material proportion is, the softening coefficients of all the samples is above 1.0. This performance overcomes the disadvantage of poor water resitant about general gypsum products. The best forming technology is 160 ℃ of forming temperature, 15 MPa of forming pressure.