高密度聚乙烯/低密度聚乙烯共混材料的模压发泡

Mould Foaming of HDPE/LDPE Blends

用模压发泡法制备了高密度聚乙烯(HDPE)/低密度聚乙烯(LDPE)共混发泡材料,研究了偶氮二甲酰胺(AC)发泡剂)、HDPE的用量及模压发泡工艺对于HDPE/LDPE共混泡沫的表观密度、力学性能的影响。结果表明,随着HDPE用量增加,共混发泡材料的表观密度、撕裂强度和拉伸强度均逐渐增加。在一定范围内,AC发泡剂用量增加,泡沫材料的表观密度和力学性能先下降后增加。发泡时间为10min时泡沫表观密度较低,再延长发泡时间,泡沫表观密度变化较小。在0MPa^10MPa范围,模压压力增加,泡沫表观密度缓慢下降。在温度为170℃~180℃范围内,温度升高,泡沫密度逐渐下降。电镜扫描图显示,HDPE/LDPE共混发泡材料泡孔均匀,且多为闭孔。

The foams of high density polyethylene（HDPE）/low density polyethylene（LDPE） blend were prepared by mould pressuring. The effects of content of azodicarbonamide （AC） foaming agent and HDPE as well as foaming process on apparent density, tensile and tear strength of the foam-were investigated. The results show the apparent density, tensile and tear strength increase as the content of HDPE increases. Apparent density and mechanical properties first drop then increase as the content of AC foaming agent increases in a certain range. Apparent density of the foam is low within foaming time of 10 minutes, then changes little with the foaming time increasing. Apparent density drops gently when the pressure increases in the range of 0MPa- 10MPa. Apparent density of the foam decreases gradually when temperature increases in the range of 170 -- 180 ℃The SEM shows the ceils of HDPE/ LDPE foams are homogeneous, and mostly closed.