Preparation of polyamide 6 microfiber reinforced polypropylene composite and its property of chemical foam injection molding

doi:10.19491/j.issn.1001-9278.2024.06.002

Abstract

Abstract:

T　he effect of compatibilizer on the nanofibril morphology， viscoelasticity， mechanical properties， and CFIM behavior of polypropylene （PP）/nylon6 （PA6） composite through a combination of in⁃situ fibrillation （INF） and chemical foam injection molding （CFIM） technologies. The results indicated that the addition of PP⁃g⁃MAH compatibilizer reduced the size of PA6 dispersion phase significantly， and PA6 microfibers were uniformly distributed in the PP matrix with an average diameter of about 265nm. The existence of a microfiber network structure and the synergistic enhancement effect of phase interface improved the mechanical strength of INF composites significantly. The tensile strength and impact strength of the composites are 26.2 % and 62 % higher than those of pure PP， respectively. Based on the CFIM experiment using the self⁃made endothermic⁃exothermic equilibrium chemical foaming agent， the INF composite foam product was prepared with a cell size of 62 μm and a cell density of nearly 5×10⁵ cells/cm³. The as⁃prepared sample obtained a decrease in the weight by 12 %. Compared to pure PP foam， the composite foam exhibited an increase in the specific tensile strength and impact strength by 17 % and 46 %， respectively.

Key words: polypropylene, in?situ fibrillation, chemical foam injection molding, cell structure, mechanical property

CLC Number:

TQ325.5

YANG Lian, JIANG Jing, JIA Caiyi, XIE Yuehan, WANG Xiaofeng, LI Qian. Preparation of polyamide 6 microfiber reinforced polypropylene composite and its property of chemical foam injection molding[J]. China Plastics, 2024, 38(6): 12-18.

Figures/Tables 9

Fig.1. Schematic fabricating process of INF composites and CFIM foams

样品	PP含量/%	PA6含量/%	PP⁃g⁃MAH含量/%	备注
PP	100	0	0	—
PP/PA6（S）	95	5	0	球形PA6 分散相的两相共混物
PP/PA6（F）	95	5	0	PP/PA6两相微纤复合材料
PP/PA6（S）/MAH	94	5	1	球形PA6分散相的三相共混物
PP/PA6（F）/MAH	94	5	1	PP/PA6/MAH三相微纤复合材料

Tab. 1. Formula of the PP⁃based composites

Fig.2. Phase morphology of all PP⁃based composites and associated size of dispersed phases of PA6

Fig.3. Phase morphologies of the injection molded samples for all PP⁃based composites

Fig.4. Dynamic frequency scanning curves of all PP⁃based composites

Fig.5. Different PP composites with variations in tensile properties， impact resistance， and the tensile fracture surface morphology of INF composite materials

Fig.6. Fracture surface morphologies of CFIM samples and cell size and distribution statistics

Fig.7. Weight loss rate， specific tensile strength and impact specific strength of all CFIM samples and fracture surface morphologies of PP/PET（F）/MAH foams

Fig.8. PA6 morphology and distribution diagram before and after foaming

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