摘要
将助剂预混与二次挤出工艺相结合制备含短纤维预发泡粒料,并用型内二次发泡工艺制备了短炭纤维(SCF)、短玻璃纤维(SGF)混杂增强聚丙烯(PP)复合泡沫材料。研究了在纤维总质量分数不变时,SCF与SGF的相对含量、增强纤维与PP的界面性能及泡沫体的表观密度对PP复合泡沫材料的发泡效果和力学性能的影响。结果表明:SGF和SCF的同时加入能够改善PP的高温熔体强度,获得孔径较小且均一的类球形的闭孔PP泡沫体。SGF和SCF混杂增强提高了PP复合泡沫材料的强度和模量,且增强效果高于单一纤维,当纤维总质量分数为15%,且SGF∶SCF为1∶1时(质量比),PP复合泡沫材料的抗弯强度和抗压强度最高,而SGF∶SCF为3∶1时,PP泡沫复合材料的冲击韧性和压缩模量达到最大值。泡沫体的表观密度对PP复合泡沫材料的冲击韧性和抗压强度影响显著,当表观密度从0.32 g/cm3增至0.45 g/cm3时,冲击韧性和抗压强度分别从4.29 kJ/m2和6.57 MPa提高到17.87 kJ/m2和20.57 MPa。
The polypropylene （PP） pre-foamed granules containing short fibers were fabricated by a combination process of the additives pre-mixing and the secondary extrusion, and then PP foamed composites hybrid-reinforced by short carbon fibers （SCF） and short glass fibers （SGF） were prepared via a post-foaming process in designed dies. The effects of the mass ratio of SCF to SGF under constant fibers loading, the interracial properties between reinforcement fibers and resin, and the apparent density of foams on the foamed result and mechanical performances of PP foamed composites were investigated. The results indicate that the high temperature melt strength of PP is improved by co-addition of SGF and SCF, which results in the formation of PP foams with fine and closed cell structure. The strength and modulus of the foamed PP composites are improved by the hybrid reinforcing of SGF and SCF and are better than those of monolithic SGF or SCF reinforced foamed PP. When the total fibers mass fraction keeps 15% and the mass ratio of SGF to SCF is 1： 1, the flexural strength and compressive modulus of foamed PP composites are optimal, and peak values of impact toughness and compressive strength are obtained at the ratio of SGF to SCF as 3 ： 1. The apparent density of PP foamed composites influences significantly the impact toughness and compressive strength of PP foamed composites, increasing from 4.29 kJ/m^2 and 6.57 MPa at 0.32 g/cm^3 to 17.87 kJ/m^2 and 20.57 MPa at 0.45 g/cm^3 , respectively.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2007年第4期1-7,共7页
Acta Materiae Compositae Sinica
基金
南京航空航天大学首届创新基金(S0279-061)
关键词
聚丙烯
发泡效果
混杂增强
力学性能
polypropylene
foaming effect
hybrid reinforcing
mechanical performance
