ABS/SBR共混体系的动态硫化技术及工艺研究

研究了动态硫化技术对丙烯腈-丁二烯-苯乙烯共聚物/丁苯橡胶(ABS/SBR)共混物性能的影响,讨论了硫化工艺条件及不同硫化剂用量对ABS/SBR共混体系的力学性能、耐热性及加工流动性的影响.结果表明,当硫化温度为180℃,螺杆转速为120 r/min时,体系混炼效果最好；在一定范围内,随着硫化剂用量的增加,体系的力学性能逐渐增强,当硫磺用量为0.6 phr时,体系的综合性能最佳.     

SBS对3D打印ABS复合材料性能的影响

用苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性苯乙烯-丁二烯-丙烯腈共聚物(ABS),制备3D打印用ABS改性复合材料,研究了SBS的用量对ABS复合材料性能的影响。采用熔体流动速率仪表征了复合材料的熔体流动速率,万能力学试验机和悬壁梁冲击试验机测试了复合材料的力学性能。研究结果表明,随SBS用量增加,复合材料的熔体流动速率增加,5%SBS的加入能使复合材料的熔体流动速率增加42.1%;随SBS用量增加,复合材料的冲击强度增加,弯曲强度降低;SBS能提高复合材料的断裂伸长率,增加其韧性,但同时也使拉伸强度降低。     

硫化剂辛基酚醛树脂对热塑性溴化丁基橡胶/聚丙烯动态硫化弹性体性能的影响

通过动态硫化的方法,以溴化丁基橡胶(BIIR)和聚丙烯(PP)为主要原料,制备热塑性BIIR/PP动态硫化弹性体。研究硫化剂辛基酚醛树脂(SP1045)的用量对BIIR/PP复合物加工性能、交联程度、力学性能和流变性能的影响。结果表明,在转矩流变仪中,当SP1045的用量从1 phr增加到5 phr时,出现动态硫化扭矩峰值的时间明显缩短,而且扭矩曲线的斜率逐渐变大。力学性能测试表明,SP1045用量从1 phr增加到3 phr时,BIIR/PP复合物的拉伸强度、硬度、100%定伸应力明显提高,但随着SP1045用量的继续增加,上述性能指标增加幅度不大。毛细管流变测试表明,BIIR/PP复合体系呈现假塑性流体特征,动态硫化使体系黏度增加,且随着SP1045用量的增加,体系黏度缓慢增大。动态流变测试表明,对于非动态硫化复合物,随着应变(γ)的增加,其储能模量(G')维持恒定;而对于动态硫化复合物,随着应变(γ)的增加,G'在一临界应变值时明显下降,进入非线性黏弹区,出现了"Payne"效应。在角频率(ω)扫描范围内,复合物的储能模量(G')、损耗模量(G″)和复数黏度(η~*)均随着硫化剂SP1045用量的增加而增加。     

硫化剂用量对低硬度动态硫化溴化丁基橡胶/聚丙烯热塑性硫化胶性能的影响

以溴化丁基橡胶(BIIR)和聚丙烯(PP)为主要原料,通过加入白油,采用动态硫化的方法制备了低硬度的BIIR/PP热塑性硫化胶,研究了硫化剂N,N'-(4,4'-亚甲基二苯基)双马来酰亚胺(BMI)的用量对其加工性能、交联程度、力学性能以及流变性能的影响。结果表明,硫化剂BMI用量为3份(质量,下同)时BIIR/PP热塑性硫化胶的综合力学性能最好;平衡转矩和交联程度都随BMI用量的增加而增大,但超过4份后的变化不大。扫描电镜分析结果显示,BMI用量为1份时BIIR/PP体系已经发生了相反转,硫化的BIIR以颗粒状分散在PP连续相中;随BMI用量增加,BIIR交联粒子被进一步细化,但大量细化的粒子出现了团聚的现象。毛细管流变测试结果表明,BIIR/PP热塑性硫化胶呈现假塑性流体特征,动态硫化使体系的黏度增加,且随BMI用量增加体系的黏度缓慢增大。     

辛基酚醛树脂动态硫化丁基橡胶/聚丙烯 热塑性硫化胶的性能研究

选用辛基酚醛树脂硫化剂,采用动态硫化法制备丁基橡胶(IIR)/聚丙烯(PP)热塑性硫化胶(TPV),研究辛基酚醛树脂硫化剂用量对TPV的流变性能、物理性能、动态力学性能和微观形貌的影响,并与IIR/PP简单共混胶进行对比。结果表明:随着辛基酚醛树脂硫化剂用量的增大,动态硫化过程中TPV熔体的转矩逐渐增大,TPV的储能模量和交联密度提高;橡塑简单共混胶的物理性能最差;随着辛基酚醛树脂硫化剂用量的增大,TPV的硬度增大,拉伸强度和拉断伸长率呈先提高后降低趋势,热老化后各项物理性能变化规律与老化前相同;橡塑简单共混胶以及采用少量辛基酚醛树脂硫化剂动态硫化TPV均有2个损耗峰,随着辛基酚醛树脂硫化剂用量的增大,TPV中IIR相的玻璃化转变温度向高温方向移动;橡塑简单共混胶断面比较平整,脊线少,随着辛基酚醛树脂硫化剂用量的增大,TPV断面变得粗糙且脊线有增多趋势。     

无卤阻燃PC/ABS合金形态结构和动态流变行为研究

将不同用量的有机磷系阻燃剂双酚A-双(磷酸二苯酯)(BDP)和聚碳酸酯(PC)、丙烯腈-丁二烯-苯乙烯(ABS)熔融共混制得无卤阻燃PC/ABS合金,采用扫描电镜和动态流变仪研究PC/ABS/BDP合金的微观结构和BDP用量对合金动态流变性能的影响,分析了微观结构和动态流变行为之间的关系。结果表明,随着阻燃剂用量的增加,PC/ABS合金相界面黏结性、熔体黏度呈下降趋势,且阻燃剂质量分数达到15%以后,降幅在低频时加剧;PC/ABS合金熔体在整个扫描频率区以黏性流动为主,阻燃剂的加入使其黏性特征更加明显。     

硬酯酸钙改性磷石膏对PC/ABS合金力学性能的影响

采用熔融挤出法制备聚碳酸酯（PC）/丙烯腈丁二烯苯乙烯共聚物（ABS）/硬酯酸钙改性磷石膏,讨论硬脂酸钙用量及改性磷石膏添加量对PC/ABS合金的力学性能影响。利用吸油值接触角测试磷石膏改性效果,并采用扫描电子显微镜、流变性能测试研究改性磷石膏的微观形貌和流变性能。结果表明,硬脂酸钙与磷石膏表面发生反应降低其表面亲水性,改性剂用量为0.5 %时对PC/ABS体系力学性能的提升效果最好;改性磷石膏最佳添加量为10 %时,PC/ABS/改性磷石膏的拉伸强度为45.29 MPa,较纯PC/ABS合金提升了9.10 %;弯曲强度为137.87 MPa,提高了25.27 %;冲击韧性为11.50 kJ/m2,提高了26.37 %。     

丁基橡胶/聚丙烯动态硫化热塑性弹性体的制备和性能研究

以丁基橡胶(IIR)和聚丙烯(PP)为基体材料,利用动态硫化的方法制备了丁基橡胶/聚丙烯热塑性弹性体(IIR/PP TPV),主要研究了硫化剂用量和制备工艺参数对IIR/PP TPV力学性能和动态力学性能的影响。结果表明,随着硫化剂用量的增加,IIR/PP TPV的力学性能得到提高,硫化剂用量为9 phr时,IIR/PP TPV的综合性能优异;动态硫化温度为180℃时,IIR/PP TPV有优异的力学性能和阻尼性能;随着动态硫化时间的增加,拉伸强度呈现先增加后减小而断裂伸长率呈现逐渐增大的趋势,硫化时间超过10 min之后,IIR/PP TPV的阻尼性能开始下降,当硫化时间为10 min时,IIR/PP TPV的力学性能和动态力学性能优异。     

超分散剂改性滑石粉填充PP复合材料的性能研究

研究了YB超分散剂改性滑石粉填充聚丙烯(PP)复合材料的流变行为及力学性能.结果表明,复合材料的熔体质量流动速率(MFR)明显提高,且随着超分散剂用量的增加,MFR增大;复合材料的表观黏度随着剪切速率增大而降低;随着滑石粉用量的增加,体系表观黏度对温度的敏感性越来越小.滑石粉用量及超分散剂用量的增加对复合材料的拉伸强度、弯曲强度以及弯曲模量都有一定的改善和提高,而对其冲击强度的影响则是先增大后降低.     

改性氢氧化钙填充硅橡胶的制备与性能研究

通过添加改性氢氧化钙降低硫化剂双25硫化硅橡胶的气味等级,并研究改性氢氧化钙对硅橡胶硫化特性、动态力学性能和物理性能等的影响。结果表明：改性氢氧化钙会影响硅橡胶的硫化过程,吸收硫化过程中产生的副产物,促进硫化反应,增大硅橡胶的交联密度、邵尔A型硬度、定伸应力和拉伸强度;当改性氢氧化钙用量为2份时,硅橡胶的综合性能最好。     

Influence of rheological properties on the sagging of polypropylene and abs sheet for thermoforming applications

The isothermal sagging resistance of different grades of conventional and a high melt strength (HMS) PP has been correlated with the rheological characteristics of the polymers, such as dynamic shear properties, melt strength, and zero shear viscosity. A thermoforming grade of acrylonitrile‐butadiene‐styrene (ABS) was used as a reference material. At 190°C, ABS had the highest viscosity and elastic modulus in the frequency range measured, showing that this polymer is highly elastic. HMS PP had a greater shear thinning behavior than conventional PP because of its broader molecular weight distribution. The tan δ of the polymers showed that conventional PP had a higher tendency to flow than HMS PP and ABS when heated above 172°C. This was confirmed with sagging experiments performed in an air circulating oven, where the rate of sagging decreased as the melt strength and the zero shear viscosity of the polymer increased.     

Effects of acrylonitrile content on PC/ABS alloy systems with a flame retardant

To investigate the effect of a flame retardant on PC/ABS alloy systems, a reactive‐type brominated epoxy resin was used as a flame retardant, and mixed with PC/ABS at various amount using a twin‐screw extruder. The rheological, morphological, mechanical, and thermal properties were investigated as a function of acrylonitrile (AN) content in ABS. The shear viscosity of the PC/ABS blend increased as the AN content in ABS increased. Temperature drastically affected the shear viscosity in the ABS matrix, but not as much in the PC matrix. A blend of PC 50% containing AN 22% is suitable to process because its shear viscosity is low in the high shear rate region and its mechanical properties drastically increase in the beginning of the PC matrix. In addition, gradual increases of heat distortion temperature were observed in the entire range of the PC content. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 417–423, 2000     

POE/硅橡胶热塑性弹性体的力学性能及加工性能研究

采用动态硫化方法制备了乙烯-丙烯共聚物(POE)/硅橡胶热塑性弹性体。考察了共混比和交联剂含量对POE/硅橡胶热塑性弹性体的力学性能以及流变加工特性的影响。结果表明,m(硅橡胶)/m(POE)为60/40,交联剂质量分数为2.5%时表现出优越的力学性能,拉伸强度达到9.8MPa,断裂伸长率达到740%。制备出的POE/硅橡胶在流变测试中表现出优越的流变性能,具有高剪切粘度低,低剪切粘度高的特点。     

TDI/BPO改性PBS的力学性能研究

本文采用扩链手段和交联手段对PBS进行改性研究。分别选用甲苯2,4-二异氰酸酯(TDI)为扩链剂,过氧化苯甲酰(BPO)为交联剂。使用乌氏黏度计、索氏抽提器对改性体系的特性黏数和交联度进行测定;使用哈克转矩流变仪、毛细管流变仪、差示扫描量热仪、万能拉力测试机等手段测试了改性体系的加工性能,流变性能,结晶与热性能,以及力学性能等。研究了扩链剂和交联剂用量对改性体系性能的影响。结果表明,随着TDI用量的增加,PBS改性体系的特性黏数逐渐增大,加工体系的平衡扭矩提高,熔体黏度呈现出增大的趋势,从而熔体强度增大。通过扩链反应,结晶温度提高,结晶度降低,熔点升高,拉伸强度变化不大,当TDI用量为1.0%时,拉伸强度最大。随着BPO用量的增加,PBS改性体系的交联度逐渐增大,加工性能得到改善,熔体黏度大幅提高,从而熔体强度增大。交联度的增大使得改性体系的结晶温度提高,结晶度和熔点均降低,拉伸强度呈现出先增大后减小的趋势。     

Recycled polycarbonate/acrylonitrile–butadiene–styrene reinforced and toughened through chemical compatibilization

To improve the utilization efficiency of recycled polycarbonate/acrylonitrile–butadiene–styrene (R-PC/ABS), we studied the mechanical, morphological, and rheological properties of R-PC/ABS with styrene–butadiene–glycidyl methacrylate (SBG), which was used to reinforce and toughen the R-PC/ABS through chemical compatibilization. Fourier transform infrared spectroscopy demonstrated that carboxyl and hydroxyl groups in R-PC/ABS reacted with epoxy groups in SBG to produce ester and ether groups. The results of scanning electron microscopy show that the domain sizes of the ABS particles decreased when the SBG content was 6 wt %; this demonstrated that the compatibility of the polycarbonate (PC) and ABS was improved after the addition of SBG. The results of the loss modulus of dynamic mechanical analysis were consistent with the morphological results, which reflected a better compatibility of PC and ABS in the modified samples. The introduction of SBG increased the molecular weight and entanglements; this improved the viscosity and storage modulus in the modified samples, as demonstrated by the rheological results. Furthermore, the mechanical properties were obviously enhanced, especially the impact strength, when the SBG content was 6 wt %; this was ascribed to the chemical reactions and improved compatibility after melt extrusion with SBG. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47537.     

Melt rheology and morphology of LLDPE/EVA blends: Effect of blend ratio,compatibilization, and dynamic crosslinking

The melt rheological properties of linear low‐density polyethylene (LLDPE)/ethylene vinyl acetate (EVA) blends were investigated with special reference to the effect of blend ratio, temperature, shear rate, compatibilization, and dynamic vulcanization. The melt viscosity of the blends determined with a capillary rheometer is found to decrease with an increase of shear rate, which is an indication of pseudoplastic behavior. The viscosity of the blend was found to be a nonadditive function of the viscosities of the component polymers. A negative deviation was observed because of the interlayer slip between the polar EVA and the nonpolar LLDPE phases. The melt viscosity of these blends decreases with the increased concentration of EVA. The morphology of the extrudate of the blends at different shear rates and blend ratios was studied and the size and distribution of the domains were examined by scanning electron microscopy. The morphology was found to depend on shear rate and blend ratio. Compatibilization of the blends with phenolic‐ and maleic‐modified LLDPE increased the melt viscosity at lower wt % of compatibilizer and then leveled off. Dynamic vulcanization is found to increase the melt viscosity at a lower concentration of DCP. The effect of temperature on melt viscosity of the blends was also studied. Finally, attempts were made to correlate the experimental data on melt viscosity and cocontinuity region with different theoretical models. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3210–3225, 2002     

Morphological,thermal, and rheological properties of nylon/acrylonitrile-butadiene-styrene alloys

Melt blends of nylon-6/modified ABS (acrylonitrile-butadiene-styrene terpolymer) have been prepared using a single screw extruder. Electron microscopic observations revealed that the rubber particles are as finely dispersed as in ABS. Both the heat of fusion and the dynamic storage modulus of the blends were linear functions of the blend composition. The melting point of nylon crystallites and glass transition temperatures of poly(acrylonitrile-co-styrene) (AS) and the rubber phase in ABS and the amorphous phase in nylon were almost independent of the composition. Very high Izod impact strength was achieved over a broad compositional range. These facts suggest that the nylon and the modified ABS are not mixed on a molecular level although there must be sufficient interaction between them. The melt viscosities were increased with an increase in the ABS component. In the region of less than 65% ABS, the viscosities bend off to the zero-shear viscosity at low shear rates. Above 65% ABS, the viscosity curves were expressed by a power law fluid. The power law index decreased with an increase in the ABS content. The activation energy of flow vs. composition curve indicated a discontinuous point between 60% and 70% ABS. The phase inversion takes place at about 65% ABS, judging from the rheological point of view.     

Melt viscoelasticity of polyethylene terephthalate resins for low density extrusion foaming

The rheological properties of conventional polyethylene terephthalate (PET) resins are not particularly suitable for low density extrusion foaming with physical blowing agents; as a result, chemically modified resins through chain extension/branching reactions are often used. Such resins have overall higher melt viscosity and higher melt strength/melt “elasticity” than unmodified materials. In this work, following a review of the prior art on PET chemical modification, an unmodified and a chemically modified resin were selected and characterized for their melt viscoelastic properties including shear and dynamic complex viscosity over a broad shear rate/frequency range, storage and loss modulus, and die swell. Certain rheological models were found to provide better fits of the entire viscosity curve for the unmodified vs. the modified resin. Foamed extrudates having variable densities (from about 1.2 to 0.2 g/cc), were prepared by carbon dioxide injection in monolayer flat sheet extrusion equipment. Foams with increasingly lower density, below 0.5 g/cc, were obtained by increasing gas pressure only in the case of the chemically modified resin. The effects of variables such as concentration of the physical blowing agent, resin rheology, resin thermal properties and choice of process conditions are related to product characteristics including density, cell size and crystallinity.     

Influences of the phenolic curative content and blend proportions on the properties of dynamically vulcanized natural rubber/acrylonitrile–butadiene–styrene blends

The vulcanization of natural rubber (NR)‐blended acrylonitrile–butadiene–styrene (ABS) was carried out with a phenolic curing agent by a melt‐mixing process. The NR compound was first prepared before blending with ABS. The effects of the phenolic curative contents (10, 15, and 20 phr) and blend proportions (NR/ABS ratio = 50 : 50, 60 : 40, and 70 : 30) on the mechanical, dynamic, thermal, and morphological properties of the vulcanized NR/ABS blends were investigated. The tensile strength and hardness of the blends increased with increasing ABS content, whereas the elongation at break decreased. The strength property resulting from the thermoplastic component and the vulcanized NR was an essential component for improving the elasticity of the blends. These blends showed a greater elastic response than the neat ABS. The thermal stability of the blends increased with increasing ABS component. Scanning electron micrographs of the blends showed a two‐phase morphology system. The vulcanized 60 : 40 NR/ABS blend with 15‐phr phenolic resin showed a uniform styrene‐co‐acrylonitrile phase dispersed in the vulcanized NR phase; it provided better dispersion between the NR and ABS phases, and this resulted in superior elastic properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42520.     

过氧化物硫化体系对AEM/三元尼龙TPV性能的影响

采用过氧化物F40和DCP两种类型的硫化体系,同比改变过氧化物硫化体系中助硫化剂和硫化剂的用量,探究硫化剂添加量对AEM/PAM15动态硫化体系的影响。结果表明,随硫化剂添加量的增加,硫化程度先增加后减小;F40与DCP相比,对材料的性能影响相似,但DCP硫化过程中伴有刺激性气味且速率过快;动态硫化后的TPV[1]与硫化前相比,多了一个界面玻璃化温度,显示了两种基料良好的结合性能。