Polystyrene (abbreviated as PS) is one of the five general-purpose synthetic resins, mainly including GPPS (general-purpose polystyrene), EPS (expandable polystyrene), and XPS (extruded expanded polystyrene). ), HIPS (impact polystyrene), PSX (cross-linked polystyrene), SAN (styrene-acrylonitrile copolymer) and ABS (acrylonitrile-butadiene-styrene copolymer), its output is only After PE (polyethylene), PVC (polyvinyl chloride) and PP (polypropylene), it ranks fourth. In 1925, the German I.G. Farben Industrial Company began to engage in the industrial production and development of styrene, and achieved industrial production in 1930 [1]. In 1958, China started the industrial production of PS resin [2]. It is estimated that global PS demand will reach 13.7 million tons in 2018, with an average annual growth rate (2013-2018) of 2.0 percentage points.
PS modified plastics are additives or other resins that use primary form of PS resin as the main component to improve the performance of the resin in one or more aspects such as mechanics, rheology, combustion, electricity, heat, light, magnetism, etc. As auxiliary ingredients, through filling, toughening, reinforcement, blending, reaction grafting, flame retardant, nanocomposite, functionalization, thermoplastic elastomer technology, alloying and other technical means, materials with uniform appearance and specific functions can be obtained.
PS is polymerized from styrene. According to the polymerization process, it can be divided into bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization and isotactic polymerization. In particular, bulk polymerization and suspension polymerization are the most common. PS is one of the most widely used general plastics in the world. It has good dimensional stability and electrical insulation properties, excellent transparency, and its transparency is second only to PMMA (polymethyl methacrylate). Therefore, it has been widely used in the automotive and engineering industries, household appliances and other fields. However, due to its hardness and brittleness, poor impact resistance and low elongation at break (2%), it has been affected by its wide application in industry. Therefore, it needs to be modified. The modification of PS began with the research and development of HIPS by DOW Chemical Company in the United States in the early 1960s. In view of the shortcomings of GPS’s low toughness and notch sensitivity, a large number of physical, chemical and other modification research work have been carried out at home and abroad in order to improve the high impact strength of PS, improve its gloss and transparency, give it better performance and expand its application fields. .
1. Physical modification
Physical modification is mainly the blending of PO/PS, PE/PS, and the blending of PS with PC, ABS, PMMA, PPO, PVC, PA, K resin, reactive PS alloy, and other blends system etc.[3].
Li Huaidong et al. [4] used the method of increasing the screw speed of the twin-screw extruder during the material melt extrusion and blending process to study the mechanical shear stress and elastomer of the twin-screw extruder under higher screw speed conditions. The type, shape, dosage and other factors influence the mechanical properties and processing flow properties of ABS/PS blend materials. The results show that the high shear stress of the twin-screw extruder can promote the dispersion of dispersed phase particles and the enhancement of interfacial bonding force, resulting in an improvement in the mechanical properties and melt flow rate of the blend material. Nitrile rubber (NBR) powder has a compatibilizing and toughening effect on ABS/PS blend materials. When the extrusion blend temperature is 220 °C, the screw speed is 720 r/min, and the NBR powder mass fraction is 10%, ABS/PS The notched impact strength of the PS blend material is 16.4 kJ/m2, which is approximately 1.6 times higher than before modification, reaching the impact toughness index of ABS resin and maintaining good processing fluidity.
Li Chiyu[5] introduced the UPES resin developed by Nova Chemical Company in the United States. The new UPES resin is a mixture of PE and PS and can be used as a processing aid for LDPE (low-density polyethylene), HDPE (high-density polyethylene) and PP. agent. Its main function is to expand the processing range of polyolefins and directly improve the properties of some polyolefins.
Zhang Yu et al. [6] prepared PP/PS blends and reactive monomers styrene (St), acrylic acid (AA) and their mixed monomers to modify PP/PS blends, and used scanning electron microscopy to (SEM), polarized light microscopy (POM) and dynamic viscoelastic spectroscopy (DMA) were used to study the phase morphology and dynamic mechanical behavior of the reactive monomer modified PP/PS blend. The results show that the reactive monomer St has a compatibilizing effect, promotes the dispersion of PS in PP, and reduces the particle size of the dispersed phase PS. The reactive monomer AA has obvious heterogeneous nucleation effect, which reduces the spherulite size of PP. The compatibilization effect of St-modified blends is more obvious than that of AA-modified blends, while the heterogeneous nucleation effect of AA-modified blends is greater than that of St-modified blends.
Chen Gong et al. [7] modified PS with MAH (maleic anhydride) to increase the compatibility between PS and PA6, and then blended MAH-g-PS and PA6 in different proportions. The results show that when the mass fraction of MAH-g-PS is added to 0.5%, the impact strength of PA6/MAH-g-PS composites increases from 468 kJ/m2 to 700 kJ/m2 respectively. In addition, the flame retardant performance and combustion performance of its composite materials have been significantly improved.
Wang Genlin et al. [8] summarized the latest progress in the blending modification research of PVC and PS, mainly adding compatibilizer to the system for modification. It is hoped that the compatibilization-crosslinking synergistic technology can be used for blend modification of this system. The compatibilization-crosslinking synergistic technology has been used to modify blends of large varieties of general plastics, such as PVC/PE, PS/PE, etc., and has achieved good results. This technology is also being studied for the modification of PVC/PS blends.
Dai Xinying et al. [9] reviewed the research methods at home and abroad using graft copolymers, block copolymers and reactive blending to improve PS/PE compatibility, and proposed that PS/PO (polymer) should continue to be developed. olefins) alloys and convert them into industrial products.
Han Yongsheng et al. [10] used glycerol and ethyl alcohol to0-103.
[4] Li Huaidong, Zhang Yuncan, Wang Yuanyuan. Research on ABS/PS blend modification [J]. Plastics Industry, 2012, 40 (2): 27-30.
[5] Li Chiyu. PE/PS copolymer modified polyolefin new material [J]. Foreign Plastics, 2012, 30 (6): 63-64.
[6] Zhang Yu, Huang Yongping, Zhou Yankun, et al. Compatibilization effect of reactive monomer modified PP/PS blends [J]. Journal of Sun Yat-sen University (Natural Science Edition), 2005, 44 (2 ): 62-64. [7] Chen Gong, Peng Chengzhou, Zhang Chi, et al. Research on the properties of PA6/MAH-g-PS composite materials [J]. Science and Technology Information, 2012 (11): 35-36.
[8] Wang Genlin, Fang Zhengping. Research progress on modification of PVC/PS blend system [J]. China Plastics, 1998, 12 (6): 19-24.
[9] Dai Xinying, Qu Minjie, Li Yang. New progress in research on PS/PE blend modification at home and abroad [J]. Plastics Manufacturing 2009 (8): 74-77.
[10] Han Yongsheng, Chongzheng. Research on the properties of PS/modified PVA blend sheets [J]. Packaging Engineering, 2010, 31 (11): 59-62.
[11] Kang Guangyu, Liu Jincheng. Research progress on syndiotactic polystyrene blend modification [J]. China Plastics, 2003, 17(6): 15-19.
[12] Yao Haijun, Yang Yongqing, Chang Xinlin, et al. Progress in polystyrene modification methods and their applications [J]. Chemical Engineering and Equipment, 2009 (7): 142-145.
[13] Zheng Junliang, Zhang Ying. Effect of mixed compatibilizers on the morphology and properties of HDPE/sPS blends [J]. Contemporary Chemical Industry, 2014, 43 (12): 2497-2501.
[14] Shi Shi, Huang Ying, Liao Zijun. Research progress on PS toughening and modification [J]. Synthetic Resins and Plastics, 2004, 21 (6): 57-70.
[15] Li Jiancheng, Bi Haipeng, Liu Tianhe. Toughening mechanism and performance influencing factors of PS series resin [J]. Elastomers, 2014, 24 (1): 67-72.
[16] Shi Wei, Liu Zhanrong, Li Zhongqiu, et al. Research on the properties of flame-retardant high-impact polystyrene/elastomer composites [J]. Plastics Technology, 2015, 43 (7): 36-39.
[17] Zhang Jinlong, Ma Fei, Chen Changqing, et al. Research progress on the effect of rubber modification on the mechanical properties of PS and its mechanism [J]. Guangzhou Chemical Industry, 2010, 38 (6): 16-19.
[18] Jiang Shijun, Yang Qi, Zhu Jiayu, et al. SBS/EP blend system modified PS [J]. Plastics, 2012, 41 (3): 7-25.
[19] BIRON M.PDL Handbook series: Thermopastics and thermoplastic composites[M]. 2nd Edition. Oxford: William Andrew Applied Science Publishers, 2013: 823-828.
[20] Su Chao, Luo Jujie, Zhao Yu, et al. Research on the formation mechanism of flame retardant carbon layer of PS/APP/EG/CaCO3 composite materials [J]. Plastics Technology, 2014, 42(5): 40-45.
[21] Hao Cen, Yan Kaili, Liu Shuguang, et al. Research on PS/OMMT nanocomposite preparation technology [J]. Plastics Technology, 2014, 42(12): 59-64.
[22] Liu Xiangfeng, Yu Jian, Zhang Jun. Research progress of polymer/layered silicate nanocomposite natural materials [J]. Journal of Qingdao University of Science and Technology, 2003, 24(3): 233-237.
[23] Li Wenfei, Cui Lei, Yao Zhanhai, et al. Preparation and characterization of polystyrene-modified nano-SiO2/low-density polyethylene grafted polystyrene composites [J]. Journal of Composite Materials, 2016, 33 ( 9): 1899-1904.
[24] You Fei, Li Yuzhen, Yang Ling, et al. Research on the flame retardant effect of flame retardant high impact polystyrene/organic montmorillonite nanocomposites (I) – traditional flame retardants and modified montmorillonite Flame retardant synergy of desoil[J]. Fire Science, 2004.04, 13(2): 123-127.
[25] Yang Mingshan. Research on the formulation of low-temperature super-tough HIPS [J]. Modern Plastics Processing and Application, 2007, 19 (2): 5-8.
[26] Wang Pan, Li Yingchun, He Maoyong, et al. Chain extension modification of waste high-impact polystyrene by oxaline [J]. Polymer Materials and Engineering, 2015, 31 (5): 77- 82.
[27] Zhang Yu, Huang Yongping, Mai Kancheng. Crystallization and melting behavior of acrylic and styrene modified PP/PS [J]. Modern Plastics Processing and Application, 2006, 18 (5): 11-15.
[28] Yin Xianze, Tan Yeqiang, Lin Lei, et al. Rheological behavior of polystyrene filled with core/shell nanocomposite particles [J]. Acta Polymer, 2012 (11): 1335-1341.
[29] Song Lixin, Ren Jiannan, Ren Liang, et al. Morphological structure and properties of core-shell modified and toughened polyphenylene ether/PS blends [J]. Plastics Industry, 2014, 42 (6): 25 -28.
[30] Wang Luming. Research on surface modification of flame-retardant Mg(OH)2 and composite effect with PS [J]. Inorganic Salt Industry, 2011, 43 (12): 29-31.
[31] Zheng Xiuting, Liu Ying, Wu Daming, et al. Effect of impact modifiers on the mechanical and flame retardant properties of halogen-free flame retardant PS [J]. Plastics, 2011, 40 (5): 68-70.
[32] Qi Guiliang. Practical modified plastic technology[M]. Beijing: Machinery Industry Press, 2015: 258-259.
[33] Cui Wenguang, Gao Yanlei, Bu Xinli, et al. Surface modification of aluminum hydroxide and its application in HIPS [J]. Chemical Engineering, 2009, 37 (4): 57-59.
[34] Jia Zhiyong, Qiang Yinghuai, Wang Peipei. Research on the application of nanomullite in PS modification [J]. Bulletin of Silicates, 2008, 27 (1): 174-178.
[35] Yu Shouwu, Sang Xiaoming, Xiao Shujuan, et al. Research progress on inorganic nanoparticle modified polystyrene [J]. Journal of Hebei University of Science and Technology (Natural Science Edition), 2009, 31 (2): 88 -92.
[36] Ma Hongxia, Chen Jingming, Guo Jianmin, et al. Research progress on modification of high-impact polystyrene I. Improvement of flame retardant properties [J]. Plastics Industry, 2007, 35 (4): 8-11.
[37] Zhang Cunwei, Li Xiangmei, Yang Rongjie. Research progress on PS flame retardant modification [J]. Engineering Plastics Application, 2016, 44 (7): 137-141.
[38] Zhou Liang. Flame retardant properties of PS/multi-walled carbon nanotube composites [J]. China Plastics, 2011, 25(6): 14-21.
[39] Huang Pengke, Pang Yongyan, Zhang Shumei, et al. Flame retardant modification of PS and foamed PS by macromolecular bromine-based composite flame retardants [J]. Engineering Plastics Applications 2016, 44 (11): 7-11 .
[40] Wang Yuzhong, Chen Li. New flame retardant materials [J]. New Industrialization, 2016, 6 (1): 38-61.
[41] Liu Minghua. Recycling Technology of Waste Polymer Materials[M]. Beijing: Chemical Industry Press, 2014: 222.
[42] Li Zhijie, Zhang Wenjie, Luo Jingke. Research on key technologies for polystyrene foam resource utilization [J]. Renewable Resources and Circular Economy, 2012, 5(6): 30-34.
[43] Zheng Gang, Wang Rumin, Du Baozhong, et al. Progress in chemical modification of waste PS [J]. China Plastics, 2009, 23 (12): 6-9
[44] Liu Yunxue, Tang Yuanliang, Li Lan, et al. Research on preparation of waterproof coating by graft modification of waste polystyrene particles [J]. China Plastics, 2015, 29 (4): 102-106.
[45] Lin Zhipeng. Review of recycling waste polystyrene (foam) plastics [J]. Plastics Industry, 2005, 33 (Supplement): 31-33.
Research Progress[J]. Engineering Plastics Applications, 2016, 44(7): 137-141.
[38] Zhou Liang. Flame retardant properties of PS/multi-walled carbon nanotube composites [J]. China Plastics, 2011, 25(6): 14-21.
[39] Huang Pengke, Pang Yongyan, Zhang Shumei, et al. Flame retardant modification of PS and foamed PS by macromolecular bromine-based composite flame retardants [J]. Engineering Plastics Applications 2016, 44 (11): 7-11 .
[40] Wang Yuzhong, Chen Li. New flame retardant materials [J]. New Industrialization, 2016, 6 (1): 38-61.
[41] Liu Minghua. Recycling Technology of Waste Polymer Materials[M]. Beijing: Chemical Industry Press, 2014: 222.
[42] Li Zhijie, Zhang Wenjie, Luo Jingke. Research on key technologies for polystyrene foam resource utilization [J]. Renewable Resources and Circular Economy, 2012, 5(6): 30-34.
[43] Zheng Gang, Wang Rumin, Du Baozhong, et al. Progress in chemical modification of waste PS [J]. China Plastics, 2009, 23 (12): 6-9
[44] Liu Yunxue, Tang Yuanliang, Li Lan, et al. Research on preparation of waterproof coating by graft modification of waste polystyrene particles [J]. China Plastics, 2015, 29 (4): 102-106.
[45] Lin Zhipeng. Review of recycling waste polystyrene (foam) plastics [J]. Plastics Industry, 2005, 33 (Supplement): 31-33.
