Microcellular Injection Foaming Behaviors and Mechanical Properties of Polypropylene/Carbon Nanotubes Composites

doi:10.19491/j.issn.1001-9278.2020.06.004

Abstract

Abstract:

The effect of the content of single?walled carbon nanotubes (CNTs) on the rheology, thermal stability, foaming behavior and mechanical properties of microcellular injection?molded polypropylene (PP)/CNTs composites was investigated. The results indicated that the complex viscosity of the composites gradually increased with an increase of CNTs content, and their thermal stability was also improved. The agglomeration occurred with the addition of 0.15 wt % CNTs, and however the size of agglomerates was fairly small and the substrates were tightly bound. The distribution of pores in the microcellular injection?molded samples was nonuniform, and the pore size ranged from 10 to 70 μm. The pore diameter decreased at first and then tended to increase with an increase of CNTs content. The elastic modulus and yield stress were found to decrease slightly after the microcellular foaming process according to the uniaxial tensile test results, and however the elongation at break increased by approximately 400 %. Moreover, there is no significant change in the mechanical properties of the foamed samples.

Key words: polypropylene, carbon nanotubes, microcellular injection molding, pore structure, mechanical property

CLC Number:

TQ320

Hongyue YUAN, Zhangyong JIN, Jing JIANG, Xianhu LIU, Zhenfeng ZHAO. Microcellular Injection Foaming Behaviors and Mechanical Properties of Polypropylene/Carbon Nanotubes Composites[J]. China Plastics, 2020, 34(6): 20-26.

Figures/Tables 10

样品名称	PP/%	CNT/%
PP/0.15 %CNT	99.85	0.15
PP/0.3 %CNT	99.70	0.30
PP/0.45 %CNT	99.55	0.45
PP/0.6 %CNT	99.40	0.60
PP/1.0 %CNT	99.00	1.00

Tab.1. Formula of PP/CNT composites

参数	实体	发泡
喷嘴温度/℃	220	220
模具温度/℃	25	25
注塑速率/cm³·s^-1	21	21
冷却时间/s	30	30
背压/MPa	5	5
SCF 流量/cm³·s^-1	-	5
SCF注塑压力/MPa	-	23
保压压力/MPa	100	-
保压时间/s	1	-

Tab.2. Processing parameters

Fig.1. SEM images of the fracture surface of solid PP/CNT composites

Fig.2. Rheological results from dynamic frequency sweep for PP/CNT composites

Fig.3. TG and DTG curves of PP/CNT composites

Fig.4. Pore morphologies of injection molded PP/CNT microcellular

Fig.5. Distribution of pore sizes of different injection molded PP/CNT microcellular samples

Fig.6. Variation of average pore size and pore density of microcellular PP/CNT composites

Fig.7. Stress?strain curves among solid and foamed PP, PP/CNT composites

Fig.8. Mechanical properties of various PP/CNT composites

References 17

1	孟鸿诚,郭鹏,吕明福,等.高熔体强度聚丙烯的应用及市场分析[J]. 石油化工, 2018, 47(8): 896⁃900.
	MENG H C, GUO P, LV M F, et al. Application and Marketing Analysis of High Strength Polypropylene [J]. Petrochemical Technology, 2018, 47 (8): 896⁃900.
2	AL⁃HADIDY A I. Engineering Behavior of Aged Polypropylene⁃modified Asphalt Pavements[J]. Construction and Building Materials, 2018, 191:187⁃192.
3	CHAFIDZ A. Enhancing Thermal and Mechanical Properties of Polypropylene Using Masterbatches of Nanoclay and Nano⁃CaCO₃: A Review[J]. Communications in Science and Technology, 2018, 3(1): 19⁃26.
4	袁洪跃,蒋晶,刘宪虎,等. 聚丙烯/纳米碳纤维复合材料微孔注射成型加工与性能研究[J]. 中国塑料, 2019, 33(1): 59⁃64.
	YUAN H Y, JIANG J, LIU X H, et al. Study on Poreparation and Properties of Polypropylene/Carbon Nanofiber Composites by Microcellular Injection Molding [J]. China Plastics, 2019, 33 (1): 59⁃64.
5	COLEMAN J N,KHAN U,BLAU W J,et al. Small but Strong:A Review of the MechanicalProperties of Carbon Nanotube⁃Polymer composites[J]. Carbon, 2006, 44(9): 1 624⁃1 652.
6	陈明,高山俊,沈春晖. 聚丙烯微发泡材料改性研究进展[J]. 中国塑料, 2018, 32 (5): 8⁃14.
	CHEN M, GAO S J, SHEN C H. Research Progoress on Modification of Micro⁃Foamed PP [J]. China Plastics, 2018, 32 (5): 8⁃14
7	SUN S,HU D,CHEN J, et al. Effects of Carbon Nanofiber on the Dissolution and Diffusion of CO₂ in Polypropylene Nanocomposites[J]. The Journal of Supercritical Fluids, 2014, 94: 252⁃260.
8	LEE B H,CHO J W,KIM K H. Crystallization, Orientationand Mechanical Properties of Laser⁃Heated Photothermally Drawn Polypropylene/Multi⁃walled Carbon Nanotube Fibers[J]. European Polymer Journal, 2017, 91:70⁃80.
9	HOU J, JIANG J, GUO H, et al. Fabrication of fibrillated and interconnected porous poly (ε⁃caprolactone) vascular tissue engineering scaffolds by microcellular foaming and polymer leaching[J]. RSC Advances, 2020, 10(17): 10 055⁃10 066.
10	SUN S,LI Q,ZHAO N, et al. Preparation of Highly Interconnected Porous Poly (ε⁃caprolactone)/Poly(lacticacid) Scaffolds Via Supercritical Foaming[J]. Polymers for Advanced Technologies, 2018, 29(12): 3 065⁃3 074.
11	GANDHI R A,PALANIKUMAR K,RAGUNATH B, et al. Role of Carbon Nanotubes (CNTs) in Improving Wear Properties of Polypropylene (PP) in Dry Sliding Condition[J]. Materials & Design, 2013, 48:52⁃57.
12	张凯. 聚丙烯碳基纳米复合材料微尺度流变实验研究[D]. 北京化工大学, 2016.
	ZHANG K. Experimental Study on Micro⁃scale Rheology of Polypropylene Carbon⁃based Nanocomposites [D]. Beijing University of Chemical Technology, 2016.
13	LIN X,ZHANG K,LI K, et al. Dependence of Rheological Behaviors of Polymeric Composites on the Morphological Structure of Carbonaceous Nanoparticles[J]. Journal of Applied Polymer Science, 2018, 135(26):46⁃50.
14	WANG X C,JING X,PENG Y Y, et al. The Effect of Nanoclay on the Crystallization Behavior, Microcellular Structure, and Mechanical Properties of Thermoplastic Polyurethane Nanocomposite foams[J]. Polymer Engineering & Science, 2016, 56(3): 319⁃327.
15	ZHANG K,WANG Y,JIANG J, et al. Fabrication of Highly Interconnected Porous Poly (ɛ⁃caprolactone) Scaffolds with Supercritical CO₂Foaming and Polymer leaching[J]. Journal of materials science, 2019, 54(6): 5 112⁃5 126.
16	GANDHI R A,JAYASEELAN V,KUMAR K P, et al. Effect of Carbon Nanotubes (CNT) on Hardness of Polypropylene Matrix.In Advances in Materials and Metallurgy, Springer, 2019, 261⁃270.
17	BAI J,LIAO X,HUANG E, et al. Control of the Cell Structure of Microcellular Silicone Rubber/Nanographite Foam for Enhanced Mechanical Performance[J]. Materials & Design, 2017, 133:288⁃298.

[1]	WU Wei, HU Huanbo, SHEN Hui, ZHAO Tianyu. Dual⁃synergistic effect of 4A zeolite and Ca⁃Mg⁃Al hydrotalcite on intumescent flame retardant PP and its mechanism [J]. China Plastics, 2022, 36(7): 1-7.
[2]	YU Changyong, XIN Zhong. Effect of α/β complex nucleating agent based on hexahydrophthalate on properties of polypropylene [J]. China Plastics, 2022, 36(7): 121-128.
[3]	TAN Liqin, LIU Weiqu, LIANG Liyan, WANG Shuo, FENG Zhiqiang, LIN Jiaming. Preparation and performance of epoxy resin modified with mercaptan polysiloxane [J]. China Plastics, 2022, 36(7): 21-29.
[4]	LIU Yi, SUN Wei, QU Guoxing, WANG Ye, YUAN Ning, YANG Shaolin, XU Xia, CHANG Xiaoyi, ZHANG Yufei. Structure and performance analysis of transparent polypropylene special material for thin⁃wall injection molding [J]. China Plastics, 2022, 36(7): 37-43.
[5]	XU Jie, ZHONG Jinfu, TONG Xiaoqian, LI Guangfu, FU Dongliang, LI Chengcheng. Preparation and performance of carboxyl⁃terminated tannic acid/gallic acid⁃based epoxy composite [J]. China Plastics, 2022, 36(7): 44-50.
[6]	LI Kaize, XIN Yong. Properties of thermoplastic polyurethane composites modified with carbon nanotubes [J]. China Plastics, 2022, 36(6): 1-5.
[7]	WANG Shuai, ZHANG Yudi, YANG Fukai, XU Xinyu. Preparation and properties of polyimide/multi⁃walled carbon nanotubes composite foams [J]. China Plastics, 2022, 36(6): 39-45.
[8]	SUN Wei, LIU Yi, LIAO Yunlong, CHEN Junjia. Study on influence factors for determination of ethylene content in polypropylene powder [J]. China Plastics, 2022, 36(6): 54-59.
[9]	WANG Jinye, TANG Bohu, YANG Lining, XIE Meng, GUO Zechao, YANG Guang. Study on multi⁃jet⁃fusion forming process of PA12 parts [J]. China Plastics, 2022, 36(6): 81-86.
[10]	SUN Wenbo, XIN Chunling, HE Yadong, ZHAI Yujiao, YAN Baorui. Influence of micro⁃foaming injection molding process on cell structure of glass⁃fiber⁃reinforced PBT products [J]. China Plastics, 2022, 36(5): 1-7.
[11]	WANG Ke, LONG Chunguang. Mechanical and tribological properties of ultra⁃high molecular weight polyethylene/sepiolite fiber composites [J]. China Plastics, 2022, 36(5): 19-23.
[12]	CHEN Sheng, LIANG Yingchao, WU Fangjuan, FANG Hui, FAN Xinfeng, CHEN Hui, WANG Yonggang. Preparation and interfacial modification of polyamide 6/bidirectional warp⁃knitted glass fiber composites [J]. China Plastics, 2022, 36(5): 24-28.
[13]	HE Hezhi, XU Li, YANG Yike. Effect of prestress on mechanical properties of PC/CF laminates [J]. China Plastics, 2022, 36(4): 1-5.
[14]	WANG Qingsong. Development of glass⁃fiber⁃reinforced polypropylene with high strength and low VOC [J]. China Plastics, 2022, 36(4): 30-34.
[15]	LI Suyuan, LIU Huipeng, GONG Shun, HUANG Guotao, LI Yucai, WU Xin, DENG Jianping, PAN Kai. Preparation and characterization of EVA foaming materials modified with thermoplastic polyamide elastomer [J]. China Plastics, 2022, 36(4): 6-14.