Toughening study of fire‐retardant high‐impact polystyrene

Fire‐retardant high‐impact polystyrene (HIPS) was modified by melt blending with varying amounts of three types of tougheners. The effects of the tougheners on the properties of the fire‐retardant HIPS were studied by mechanical, combustion tests, and thermogravimetric analysis. The morphologies of fracture surfaces and char layers were characterized through scanning electron microscopy. The results show that the impact properties of styrene–butadiene–styrene (SBS)‐containing composites were better than those of ethylene–propylene–diene monomer (EPDM)‐containing or ethylene–vinyl acetate copolymer (EVA)‐containing composites. The tensile strength and flexural modulus of the fire‐retardant HIPS decreased evidently with the addition of tougheners. It is found that the compatibility between SBS copolymer and HIPS matrix was best among the three types of tougheners. The addition of SBS had little influence on the thermal property, residue, flammability, and morphology of char layer of the fire‐retardant HIPS, but the addition of EPDM rubber or EVA brought adverse influence on the residue, flammability, and morphology of char layer of the fire‐retardant HIPS, especially for EPDM. Copyright © 2009 John Wiley & Sons, Ltd.     

Flame retardancy and toughening of high impact polystyrene

Flame retardant high impact polystyrene (HIPS) was prepared by melt blending HIPS, nano‐modified aluminum trihydrate (nano‐CG‐ATH), red phosphorus masterbatch (RPM), and modified polyphenylene oxide (MPPO). Styrene‐butadiene‐styrene (SBS) was used as a toughener in this research. The effects of nano‐CG‐ATH, RPM, MPPO, and SBS on properties of HIPS composites were studied by combustion test, mechanical tests, and thermogravimetric analysis. The morphologies of fracture surfaces and char layers were characterized through scanning electron microscopy (SEM). The HIPS/nano‐CG‐ATH/RPM/MPPO (60/6/9/25) composite and its combustion residues at various temperatures were characterized by Fourier transform infrared (FTIR) spectra analysis. The results showed that the UL‐94 rating of the HIPS/nano‐CG‐ATH/RPM/MPPO (60/6/9/25) composite reached V‐0 and its char layer after flame test was integrated, but its impact strength was low. Addition of SBS improved its impact property and did not influence its thermal and flame retardant properties but lowered its tensile strength and flexural modulus to some extent. The FTIR spectra confirmed that the P O C group was present in the charred substance. POLYM. COMPOS., 28:551–559, 2007. © 2007 Society of Plastics Engineers     

Transparent,fluorescent, and mechanical enhanced elastomeric composites formed with poly (styrene‐butadiene‐styrene) and SiO2‐hybridized CdTe quantum dots

Transparent poly(styrene‐butadiene‐styrene) (SBS)‐quantum dots (QDs) composites (SBS/CdTe QDs) that simultaneously possess strong photoluminescence (PL) and enhanced mechanical properties are presented for the first time based on the facile blending of SiO₂‐hybridized CdTe QDs with SBS. UV–vis spectrum and fluorescence measurement show that SBS/CdTe QDs composites exhibit good optical properties. The results of transmission electron microscopy show good dispersion of CdTe QDs in the SBS matrix. The results of dynamic mechanical thermal analysis indicate that the micro‐phase separated structure of the SBS is exist in the composites, and the presence of CdTe QDs can lead to an decrease of glass transition temperatures of polybutadiene (PB) and polystyrene(PS) domains. In addition, mechanical tests reveal that the addition of CdTe QDs is a useful approach to improve the mechanical properties of SBS. Meanwhile, the fluorescent photographs taken under ultraviolet light prove that SBS/CdTe QDs composites possess strong PL. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

动态硫化BR/EVA/SBS/HIPS热塑性弹性体的增强研究

采用动态硫化法制备了顺丁橡胶(BR)/乙烯-醋酸乙烯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯共聚物(SBS)/高抗冲聚苯乙烯(HIPS)热塑性弹性体(TPE),通过在BR中充填炭黑的方式对复合体系进行增强,对其力学性能及断面微观结构进行了研究。结果表明,对于动态硫化BR/EVA/SBS/HIPS共混型TPE,当BR相中炭黑填充量在0~80phr的范围内,其动态硫化产物均表现出TPE的特征;随着炭黑用量的提高,复合体系的拉伸强度、撕裂强度、邵氏硬度趋于显著提高,断裂伸长率趋于下降,而扯断永久形变则趋于不变;未填充炭黑TPE的拉伸断面上两相界面结合良好;炭黑填充后的TPE的断面起伏较大但平滑,表明弹性较强。     

Photooxidative degradation of styrenic polymers: 13C-NMR and morphological changes upon irradiation

Thin films of high impact polystyrene (HIPS 8350) and styrene–butadiene–styrene triblock copolymers (SBS) were exposed to polychromatic light for different time intervals in SEPAP 12/24 at 55°C in atmospheric air. The photooxidized samples were analyzed by ¹³C-NMR spectroscopy in the liquid state. Epoxides and alcohols were photoproducts in the SBS. Epoxides were not observed in the HIPS. The morphological changes of the solution cast HIPS and SBS films caused by irradiation were studied by scanning electron microscopy. The property deterioration was explained in terms of scission reactions in the HIPS and SBS matrix. The micrographs indicate that both materials are of a two phasic system. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 637–645, 1998     

极性化SBS／增粘树脂共混物的相容性研究

利用动态力学分析(DMA)方法,研究了吡啶基官能化的SBS(极性化SBS或SBSVP)热塑弹性体与数种增粘树脂共混物的动态力学性能,以此表征SBSVP与不同增粘树脂的相容性.试验结果表明,SBSVP与不同增粘树脂共混后,共混物的玻璃化转变温度(Tg)会发生相应的变化,表明不同种类的增粘树脂与SBSVP中PS及PB相的相容性各不相同.其相客性为以下几种情况不同程度的组合:树脂与SBSVP中的PB相相容;树脂与PS相相容;树脂与PB、PS相都相容;树脂与PB、PS相都不相容.同时可能会有过渡相和中间相的产生.     

碳酸钙填充改性聚苯乙烯

采用热塑性弹性体SBS作为增韧改性剂,碳酸钙作为填充剂改性PS,讨论了SBS含量和碳酸钙含量对共混物力学性能、热性能、加工性能的影响.研究结果表明:当SBS质量分数达到20%,碳酸钙质量分数达到45%时,共混物的冲击强度和热性能都得到提高,但拉伸强度有所下降,性能接近HIPS.本法生产工艺简单、成本降低,适宜于生产注塑制品.     

Optical transparency,thermal resistance,intermolecular interaction,and mechanical properties of poly(styrene‐butadiene‐styrene) copolymer‐based thermoplastic elastomers

The optical transparency, thermal resistance, intermolecular interaction, and mechanical properties of poly(styrene‐block‐butadiene‐block‐styrene) (SBS), which were modified by blending with crystalline polypropylene (PP) or amorphous polystyrene (PS), were analyzed. The dynamic mechanical test indicated that the PP exhibited an intermolecular interaction with SBS and PS was compatible with SBS. The optical properties indicated that the direction of the light was changed due to the difference between the refractive indices of SBS and the added modifiers. Additionally, refraction and reflection occurred at the interface, reducing the transparency of SBS. The thermal resistance of SBS clearly improved upon modification by the addition of crystalline PP polymer. The thermal treatment increased the tensile strength and the elongation at breakage of modified SBS by reducing the internal stress, which was generated during the blending process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Photodegradation of thermodegraded polypropylene/high‐impact polystyrene blends: Mechanical properties

The influence of the addition of high‐impact polystyrene (HIPS) on polypropylene (PP) photodegradation was studied with blends obtained by extrusion with and without styrene–butadiene–styrene (SBS) copolymer (10 wt % with respect to the dispersed phase). The concentrations of HIPS ranged from 10 to 30 wt %. The blends and pure materials were exposed for periods of up to 15 weeks of UV irradiation; their mechanical properties (tensile and impact), fracture surface, and melt flow indices were monitored. After 3 weeks of UV exposure, all of the materials presented mechanical properties of the same order of magnitude. However, for times of exposure greater than 3 weeks, an increasing concentration of HIPS resulted in a better photostability of PP. These results were explained in light of morphological observations. This increase of photostability was even greater when SBS was added to the blends. It was more difficult to measure the melt flow index of the binary PP/HIPS blends than that of PP for low concentrations of HIPS; this was most likely due to energy transfer between the blend domains during photodegradation. This phenomenon was not observed for the ternary blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fabrication of Damping Material over Broad Temperature Range: Blending Amorphous Styrene‐Butadiene‐Styrene Triblock Copolymer with Semi‐Crystalline Syndiotactic 1,2‐Polybutadiene

Broad‐temperature‐range (?85.4 to 96.2 °C) damping material was fabricated by blending amorphous styrene‐butadiene‐styrene triblock copolymer (SBS) with semicrystalline syndiotactic 1,2‐polybutadiene (s‐PB). According to dynamic mechanical thermal analysis (DMTA) analysis, SBS/s‐PB blends exhibited three consecutive damping peaks at ?85.4, 2.7, and 96.2 °C. The peaks at ?85.4 and 96.2 °C were associated with the glass transition of polybutadiene and polystyrene in SBS, and peak at 2.7 °C belonged to the glass transition of s‐PB. The analysis of rheological behavior and thermal properties showed that the mobility and thermal stability of SBS/s‐PB blends improved with the introduction of semi‐crystalline s‐PB. Moreover, regarding the results of DMTA, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) measurements, SBS and s‐PB were compatible in the macroscopic scale while they were immiscible in thermodynamic scale. Wide‐angle X‐ray diffraction (WAXD) results present the crystal structure of blends were unchanged. Besides, with the introduction of s‐PB in blends, 100% tensile modulus increased from 3.2 to 5.8 MPa and tear strength increased from 49.2 to 84.2 kN/m. The Kerner–Uemura–Takayanagi model was employed to compare with experimental data. Thus, broad‐temperature‐range damping material was fabricated by blending SBS with s‐PB and the material combined with good processability, thermal stability, and mechanical properties. J. VINYL ADDIT. TECHNOL., 26:336–347, 2020. © 2019 Society of Plastics Engineers     

Recycling of acrylonitrile–butadiene–styrene and high‐impact polystyrene from waste computer equipment

Acrylonitrile–butadiene–styrene (ABS) and high‐impact polystyrene (HIPS) are two of the plastics most frequently used as outer casings for computer equipment such as monitors, keyboards, and other similar components. We assessed the effects of the recycling and blending of ABS and HIPS on mechanical properties. We found that the effects of recycling on ABS and HIPS were similar, in that changes in glass‐transition temperatures, tensile strengths, and tensile moduli were negligible, but strains to failure and impact strengths were reduced considerably. Blending proportions of ABS and HIPS caused no more deterioration in properties than occurred as a result of the recycling process, and the presence of small proportions of one material in the other actually restored significant amounts of ductility, as seen by increases in the strains to failure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 572–578, 2002     

充油BR/EVA/SBS/HIPS TPV的结构与性能

采用动态硫化法制备了充油顺丁橡胶(BR)/乙烯-醋酸乙烯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯共聚物(SBS)/高抗冲聚苯乙烯(HIPS)共混型热塑性硫化胶(TPV),研究了在树脂相中填充芳烃油对TPV性能和亚微观结构的影响.结果表明,随着芳烃油用量的提高,TPV的硬度、拉伸永久变形、强度均呈显著下降趋势,而拉断伸长...     

增韧阻燃高抗冲聚苯乙烯的研制

采用接枝(乙烯/丙烯/二烯)共聚物(EPDM)、K胶、(苯乙烯/丁二烯/苯乙烯)共聚物(SBS)和粉末丁腈橡胶(NBR)为高分子材料增韧剂,十溴联苯醚和三氧化二锑为阻燃剂,高抗冲聚苯乙烯(HIPS)为基体树脂通过共混、挤出过程制得增韧阻燃HIPS复合材料。对该复合材料的力学性能、阻燃性能进行测试,分析了该复合材料的微观结构,并讨论了复合材料的增韧机理。结果表明,SBS比其它3种增韧剂的增韧作用明显,并有良好的阻燃效果。     

BR/EVA/HIPS TPV的制备和性能研究

采用苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改善BR/乙烯-乙酸乙烯酯共聚物(EVA)/高抗冲聚苯乙烯(HIPS)共混物的界面相容性,通过动态硫化法制备BR/EVA/HIPS TPV,并对其性能进行研究.结果表明:未加入SBS的BR/EVA/HIPS共混物未表现出橡胶类弹性体特征,而加入适量SBS的共混物表现出典型橡胶类弹性体特征;当SBS用量为8～12份时,BR/EVA/HIPS TPV的综合物理性能较好,拉伸断面平滑,界面相容性良好.     

SBS/LDPE共混型热塑性弹性体的性能研究(Ⅱ)

选用苯乙烯-丁二烯-苯乙烯弹体(SBS)和低密度聚乙烯(LDPE)为主体材料,采用部分动态硫化法制备了一类性能良好的材料———SBS LDPE共混型热塑性弹性体(TPE),具有力学强度高,断裂伸长率大,可重复加工等特点,并研究了共混方法、硫化温度、硫化时间等工艺方面因素对动态硫化SBS LDPE热塑性弹性体力学性能的影响。     

Compatibilization of polyethylene/poly(propylene)/polystyrene blends

The compatibilization of mixtures of polyolefins or of polyolefins with polystyrene using either liquid polybutadiene (l-PB)/organic peroxide or styrene-butadiene-styrene (SBS) block copolymers was investigated. Tensile impact strength was chosen as a measure of compatibility. Binary blends LDPE/high-impact polystyrene (HIPS) and LDPE/poly(propylene) (PP) as well as LDPE/HDPE/PP/HIPS blends were prepared by blending in the chamber of a Brabender Plasticorder. Composition of the blends corresponds to real commingled plastic waste. It was found that l-PB-based compatibilizer enhanced the impact strength of LDPE/HIPS blends with LDPE contents higher than 60 wt.-% only. Also SBS copolymer enhanced the impact strength of LDPE/PP blends with LDPE contents higher than 40 wt.-%. Both the compatibilizers substantially increased the toughness of LDPE/HDPE/PP/HIPS blends with composition similar to the municipal plastic waste.     

Study on poly(2,6-dimethyl-1,4-phenylene oxide)/SBS triblock copolymer blends

The relationship between the miscibility and the physical properties of polymer blends of poly(2,6-dimethyl-1,4-phenylene oxide) and polystyrene (PS), high-impact polystyrene (IPS) and poly(styrene-block-butadiene-block-styrene) (SBS), which are blended in different compositions by a twin-screw extruder is discussed. The three types of SBS that were used are SBS1, SBS2 and SBS3 having different styrene/butadiene ratios. Dynamic mechanical analysis and differential scanning calorimetry were used to study the miscibility. The morphology was examined by SEM. The miscibility of the blends decreases with decreasing PS content. The notch sensitivity is improved by blending. Finally, the micelle model was used to explain the testing phenomena.     

Toughening of recycled polystyrene used for TV backset

The recycled polystyrene (rPS) was toughened with ethylene‐octylene copolymer thermoplastic elastomer (POE) and high‐density polyethylene (HDPE) with various melt flow index (MFI), compatibilized by styrene‐butadiene‐styrene copolymer (SBS) to enhance the toughness of rPS for use as TV backset. The rPS/POE binary blends exhibited an increased impact strength with 5–10 wt % POE content followed by a decrease with the POE content up to 20 wt %, which could be due to poor compatibility between POE and rPS. For rPS/POE/SBS ternary blends with 20 wt % of POE content, the impact strength increased dramatically and a sharp brittle‐ductile transition was observed as the SBS content was around 3–5 wt %. Rheological study indicated a possible formation of network structure by adding of SBS, which could be a new mechanism for rPS toughening. In rPS/POE/HDPE/SBS (70/20/5/5) quaternary blends, a fibril‐like structure was observed as the molecular weight of HDPE was higher (with lower MFI). The presence of HDPE fibers in the blends could not enhance the network structure, but could stop the crack propagation during fracture process, resulting in a further increase of the toughness. The prepared quaternary blend showed an impact strength of 9.3 kJ/m² and a tensile strength of 25 MPa, which can be well used for TV backset to substitute HIPS because this system is economical and environmental friendly. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

ABS/HIPS共混材料的改性研究

研究了(丙烯腈/丁二烯/苯乙烯)共聚物(ABS)与高抗冲聚苯乙烯(HIPS)质量比对ABS/HIPS共混材料力学性能和加工流动性的影响,并着重对质量比分别为80/20和70/30的两种ABS/HIPS共混材料进行了改性研究。结果表明,氯化聚乙烯(PE-C)、(苯乙烯/丁二烯/苯乙烯)嵌段共聚物(SBS)和K树脂对ABS/HIPS共混材料有不同程度的增容增韧改性作用。如采用9份PE-C与3份SBS并用改性的ABS/HIPS(70/30)共混材料的拉伸强度为27.04MPa,冲击强度为32.60kJ/m2,比改性前约提高2.7倍。转矩流变仪分析表明,PE-C、SBS和K树脂改性的ABS/HIPS共混材料加工流动性和稳定性良好。维卡软化温度测试表明,改性后ABS/HIPS共混材料的耐热性能略有降低,但影响不大。扫描电子显微镜照片清晰反映出改性后ABS与HIPS两相的相容性得到了改善。     

Physical and mechanical properties of photopolymerized SBS–methacrylic monomer systems

An exploratory study on physical and mechanical properties—transmittance, pendulum hardness, dynamic‐mechanical, and tensile—of photopolymerized styrene–butadiene–styrene block copolymer (SBS)–methacrylic monomer systems at different compositions was carried out. The insoluble and crosslinked polymerized systems prepared exhibit a high transmittance along the visible light region and retain the regular structure corresponding to the matrix (SBS), that is, the dynamic‐mechanical spectra show the two peaks corresponding to the PS and PB phases in the tan δ–temperature plot. Trapped radicals remain in the photopoymerized SBS–methacrylic monomer (tetra or hexafunctional) system, so when these systems are heated above their vitreous transition temperature, a postpolymerization reaction is produced that gives rise to an increase of both the crosslinking density and the storage modulus. The modulus and ultimate tensile strength of the polymerized SBS–hexanediol dimethacrylate (HDDMA) systems increase with increasing initial proportions of the dimethacrylate monomer; on the contrary, the percent elongation at break and toughness decrease with increasing proportions of initial dimethacrylate monomer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2857–2864, 2003