纳米SiO_2驻极体/聚乳酸复合熔喷非织造材料的制备及性能

Preparation and properties of nano-SiO_2 electret/PLA composite meltblown nonwovens

采用纳米SiO_2为驻极体,经过表面改性与聚乳酸(PLA)复合,利用双螺杆挤出机制备了纳米SiO_2/PLA复合熔喷切片,并通过工业级熔喷生产线试制了纳米SiO_2/PLA复合熔喷非织造材料。利用FTIR分析了纳米SiO_2的表面改性效果,利用DSC分析了纳米SiO_2/PLA复合熔喷切片在熔喷快速冷却条件下的结晶性能,利用滤料综合性能测试台和SEM研究了纳米SiO_2/PLA复合熔喷非织造材料的过滤性能及微观形貌,最后采用质量损失法评估了纳米SiO_2/PLA复合熔喷非织造材料的降解性能。研究结果表明:经表面改性处理,纳米SiO_2表面附上了有机活性基团;在100℃/min的冷却条件下纯PLA的结晶分数较低,纳米SiO_2驻极体的加入有助于PLA的结晶;少量纳米SiO_2驻极体的添加可显著提高PLA复合熔喷非织造材料的过滤效率,其中质量分数0.75%的纳米SiO_2添加量可使过滤效率达到99.69%,接近商用高效空气过滤器(HEPA)级聚丙烯(PP)过滤效率;在中性水解环境下,纳米SiO_2/PLA复合熔喷非织造材料具备可降解性能,经8个月质量降解至79.57%。

A kind of nano-SiO2/PLA meltblown chip,composited with the surface modified nano-SiO2 electret and PLA resin,was prepared by two-screw extruder.After meltblown manufacturing,the nano-SiO2/PLA composite meltblown nonwovens were obtained.FTIR testing was used to evaluate the effect of surface modification of nano-SiO2.DSC testing was used to investigate the crystallinity of nano-SiO2/PLA meltblown chips at fast cooling process like melt-blowing.Filter media testing platform and SEM testing were used to investigate the filtration property and micromorphology of the nano-SiO2/PLA composite meltblown nonwovens respectively.The mass loss method was used to evaluate the degradation property of the nano-SiO2/PLA composite meltblown nonwovens in the end.The results show that after modification the surface of nano-SiO2 has been covered with organic functional groups.At 100℃/min cooling rate,the crystallinity of neat PLA is quite low while adding nano-SiO2 electret can remarkably improve it.A small amount addition of nano-SiO2 electret can notably enhance the filtration efficiency of PLA composite meltblown nonwovens,as the composite with 0.75wt% nano-SiO2 has a high filtration efficiency of99.69%,which is close to the commercialized high efficiency particulate air filter（HEPA）level PP product.The nano-SiO2/PLA composite meltblown nonwovens are degradable at neutral hydrolysis condition,of which the mass drop to 79.57% after 8months degrading.