发泡废纸板纤维/LDPE复合材料的加工流变性及泡孔形态

以废弃瓦楞纸板纤维和低密度聚乙烯(LDPE)为基体辅以相应的相容剂、 润滑剂和发泡剂, 利用挤出发泡法制备了发泡废纸板纤维/LDPE木塑复合材料。通过熔融指数仪研究了废纸板纤维含量、 相容剂马来酸酐接枝聚乙烯(MAH-g-PE)的用量、 润滑剂的种类与用量以及发泡剂偶氮二甲酰胺(AC)的用量对该复合材料加工流变特性的影响; 并利用SEM观察不同熔融指数的复合材料对泡孔形态的影响。结果表明: 随着废纸板纤维含量的增加, 复合材料的熔融指数(MFI)迅速下降; MAH-g-PE增加了纤维填料与树脂基体之间的相互作用, 复合材料的熔融指数随着相容剂用量的增加先降低后升高, 其含量的转变点为15%; PE蜡对复合材料的综合润滑作用最明显, 复合材料的熔融指数随着PE蜡的含量呈近线性变化; AC发泡剂的加入降低了复合材料的熔融指数, AC发泡剂的含量超过5%将使复合材料产生明显的壁滑移; 随着熔融指数的增加, 复合发泡材料的泡孔逐渐变大, 当熔融指数为1.5时, 泡孔大小适中且分布均匀。

Processing rheology properties and cell morphology of foamed recycled paperboard fiber/LDPE composites

The foamed recycled corrugated paperboard fiber/low density polyethylene(LDPE) composites were prepared by blending co-rotating extruder with recycled paper fiber and LDPE as the main materials, the compatilizer, lubricant, foaming agent as the additives. The processing rheology properties of above mentioned composites were investigated with industrial melt flow indexer by taking the concentration of recycled paper fiber, compatilizer, lubricant and foaming agent into consideration. And SEM was used to observe the influence of different melt index on cell morphology of foamed composites.The results show that: the melt flow index (MFI) of the composites declines with the increase of the recycled paper fiber concentration; The adding of MAH-g-PE enhances the interaction between the two main phases and the MFI of the composites drops after a ascension with the peak point of about 15%; PE wax performs the best lubricant effect herein and the MFI of the composites increases linearly with the loading of the PE wax; The AC foaming agent promotes the reduction of the MFI of the foamed composites, and the wall slipping effect occurs at the AC concentration beyond 5%; With the increase of MFI, the size of cell increases. When the MFI is 1.5, the size of cell is uniform and medium.