不同化学结构的PP对热塑性弹性体复合材料性能的影响

研究了不同化学结构的聚丙烯(PP)对苯乙烯-乙烯/丁烯-苯乙烯共聚物(SEBS)/白油/PP热塑性弹性体复合材料力学性能和流动性能的影响。结果表明,复合材料的力学性能与所添加PP的力学性能保持一致,按照均聚PP、无规共聚PP、共聚PP的化学结构特性,复合材料的拉伸性能、弯曲性能和硬度都依次变小;但是复合材料的流动性能不仅和PP的熔体质量流动速率(MFR)有关系,而且还与PP和SEBS的相互作用有关。在PP的MFR相同的情况下,复合材料的MFR按照均聚PP、无规共聚PP、共聚PP的不同依次降低。     

SEBS/PP热塑性弹性体的制备与性能研究

以苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)和聚丙烯(PP)为基体树脂,以碳酸钙(CaCO3)为填充材料,用氢化白油调节其硬度及加工流动性,在一定的工艺条件下添加助剂用开炼机混炼制备SEBS/PP热塑性弹性体;研究了氢化白油、CaCO3和热塑性弹性体等对SEBS/PP共混体系性能的影响。     

SEBS/PP热塑性弹性体阻尼性能研究

以苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)和聚丙烯(PP)为基体材料,采用HAAKE转矩流变仪制备SEBS/PP热塑性弹性体,利用动态热机械分析仪研究PP和填充油用量对SEBS/PP热塑性弹性体力学性能、动态力学性能的影响,进而通过添加萜烯树脂来研究提高热塑性弹性体阻尼性能的方法。结果表明:PP的加入改善了SEBS/PP共混体系的力学性能,但随着PP用量的增加,热塑性弹性体阻尼因子的峰值逐渐下降;SEBS/PP共混体系在添加20 phr PP时,综合性能最佳;随着萜烯树脂用量的增加,阻尼因子的峰值向高温方向移动,且有效温域(阻尼因子tanδ0.3)明显加宽;在添加50 phr萜烯树脂时,热塑性弹性体的tanδ峰值向高温移动20℃左右,且在tanδ0.3的范围内温域拓宽19℃,阻尼性能明显提高;随着填充油用量的增加,SEBS/PP热塑性弹性体的力学性能下降,tanδ峰值变大,阻尼温域变窄,充油比在1:1.1时SEBS/PP热塑性弹性体的综合阻尼效果更好。     

YY–503在无卤阻燃PPE/SEBS共混体系中的应用

系统研究了多功能粉体改性剂YY–503对无卤阻燃聚苯醚(PPE)/苯乙烯-乙烯/丁烯-苯乙烯嵌段共聚物(SEBS)共混体系拉伸性能、弯曲性能、加工流变性能、表面光泽度、白度和阻燃性能的影响。随着YY–503用量的增加,共混体系的拉伸强度、断裂伸长率、弯曲强度和弯曲弹性模量均呈现先增加后减小的变化趋势,其最大值分别为40.8 MPa,46.8%,62.8 MPa和2 281 MPa;共混体系的缺口冲击强度和表面光泽度随YY–503用量的增加逐步增大;共混体系的熔体黏度较高,YY–503的加入能延长塑化时间,但降低熔体黏度效果不理想;白度测试结果发现,当YY–503质量分数为1%时,共混体系的L值比与未添加时提高5.9%;当YY–503质量分数为0.5%~1%时,共混体系的阻燃等级达到V–0级。当YY–503质量分数为1%时,无卤阻燃PPE/SEBS共混体系具有良好的综合性能和较高的性价比。     

低光泽ASA材料研究

研究了不同流动性苯乙烯–丙烯腈塑料(SAN)、填料、弹性体和消光剂对丙烯腈–苯乙烯–丙烯酸酯塑料(ASA)材料光泽度及其它性能的影响。结果表明,降低SAN的流动性对ASA材料光泽度降低很小。添加填料可明显降低ASA材料的光泽度,但会降低ASA材料悬臂梁缺口冲击强度。添加片状滑石粉和云母对ASA材料光泽度的降低最明显。选用氢化苯乙烯–丁二烯–苯乙烯嵌段共聚物(SEBS)和马来酸酐接枝聚乙烯–辛烯共聚物(POEg-MAH)弹性体可大幅降低ASA材料的光泽度,而且添加SEBS弹性体还能提高材料的悬臂梁缺口冲击强度。添加交联苯乙烯–丙烯腈无规共聚物消光剂可显著降低ASA材料的光泽度,且对材料的悬臂梁缺口冲击强度影响较小。     

充油SEBS/PP热塑性弹性体的制备及性能研究

采用HAAKE转矩流变仪制备了充油苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物/聚丙烯(SEBS/PP)热塑性弹性体,利用热重分析(TG)、差示扫描量热法(DSC)等研究了填充油对SEBS/PP加工性能、热稳定性和力学性能的影响,并考察了该充油SEBS/PP中PP的结晶行为。结果表明:填充油的加入可以明显改善SEBS/PP的加工性能。在各种充油SEBS/PP体系中,添加了石蜡油KP6030的SEBS/PP体系具有最优综合力学性能,而且该体系的热分解温度最高、失重率最低、热稳定性能最好。另外在充油SEBS/PP体系中,PP的结晶温度降低、结晶度基本不变、结晶速率加快。     

适用于3D打印技术的ABS/SEBS复合材料制备

采用热塑性弹性体苯乙烯–乙烯–丁烯–苯乙烯嵌段共聚物(SEBS)对丙烯腈–丁二烯–苯乙烯塑料(ABS)进行改性,制备3D打印ABS/SEBS复合材料,研究了SEBS的用量对3D打印ABS/SEBS复合材料流动性能、力学性能与热降解行为的影响。结果表明,随SEBS用量的增加,ABS/SEBS复合材料的熔体流动速率先增加后降低;随SEBS用量增加,ABS/SEBS复合材料的冲击强度增加,SEBS能提高ABS/SEBS复合材料的断裂伸长率,但同时也使拉伸强度和弯曲强度降低;随SEBS用量的增加,ABS/SEBS复合材料的热稳定性增加;当SEBS质量分数为15%时,ABS/SEBS复合材料在3D打印中的综合性能最好。     

弹性非织造布用SEBS/PP共混料的制备及其可纺性研究

以低相对分子质量苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)和聚丙烯(PP)为原料,制得SEBS/PP共混料,然后通过熔融纺丝制备弹性非织造布用SEBS/PP纤维,研究了SEBS/PP共混体系的流变性能、热学性能和力学性能,并对其可纺性进行了探索.结果表明:在低相对分子质量SEBS中添加高熔体流动指数PP后,可在保...     

低挤出加工温度耳机线专用热塑性弹性体复合材料的制备及性能研究

系统研究了不同化学结构的聚丙烯(PP)、苯乙烯-乙烯/丁烯-苯乙烯共聚物(SEBS)和碳酸钙对热塑性弹性体复合材料挤出加工温度的影响。实验结果表明,PP的化学结构和PP的添加量是影响复合材料的挤出加工温度的两个最重要因素,低熔点的无规共聚PP和低PP添加量可以有效降低材料的挤出加工温度;SEBS的摩尔质量和碳酸钙的含量对材料的加工温度无劣化作用。     

黑滑石粉在SEBS/PP热塑性弹性体中的应用

表征了黑滑石粉的基本物理性能,并将其填充改性在苯乙烯-乙烯/丁烯-苯乙烯/聚丙烯(SEBS/PP)热塑性弹性体中,测试了SEBS/PP热塑性弹性体的力学性能、密度、硬度及熔融指数,并分析了黑滑石粉颗粒在SEBS/PP热塑性弹性体中的分散情况。结果表明,随着黑滑石添加量的逐渐增大,SEBS/PP热塑性弹性体的拉伸强度、断裂伸长率和熔融指数均表现出先增大后下降趋势,SEBS/PP热塑性弹性体的密度和硬度均表现出逐渐增大趋势,黑滑石粉粒径越小,SEBS/PP热塑性弹性体拉伸强度、断裂伸长率和硬度越大,熔融指数越低。     

PP/丙烯基弹性体/SEBS医用热塑性弹性体的性能

以聚丙烯(PP)、丙烯基弹性体和苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)为主要原材料,采用熔融共混改性方法制备PP/丙烯基弹性体和PP/丙烯基弹性体/SEBS两种热塑性弹性体。采用转矩流变仪、拉伸试验机、硬度计和雾度计分别对共混体系的流变性能、拉伸性能、硬度和透光率进行分析与表征。结果表明,随着PP/丙烯基弹性体配比的增加,二元共混体系的平衡扭矩降低、硬度(邵A)提高、透光率变好、断裂伸长率增加,当其配比为1∶1时,共混体系的拉伸强度达到最大值(34.2 MPa);当PP与丙烯基弹性体配比为1:1不变时,随着SEBS含量增加,三元共混体系的平衡扭矩增大、硬度(邵A)减小、透光率变差、断裂伸长率提高;当PP、丙烯基弹性体和SEBS配比为47.5∶47.5∶5时,共混体系的透光率可达87%,硬度(邵A)为87,拉伸强度为35.2 MPa,断裂伸长率为750%,100%定伸强度为11.8 MPa,可满足医疗输液器械的要求。     

Rheological behaviors of glass bead‐ and wollastonite‐filled polypropylene composites modified with thermoplastic elastomers

Steady‐ and oscillatory‐shear rheological behaviors of polypropylene/glass bead (PP/GB) and PP/wollastonite (PP/W) melts modified with thermoplastic elastomers, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and the corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were examined by means of a parallel‐plate rheometer. With adding the elastomers (SEBS and SEBS‐g‐MA) and fillers (spherical GB and acicular W) to PP, viscosity especially at low shear rates and shear‐thinning flow behavior at high shear rates were pronounced as evidenced quantitatively by Carreau–Yasuda (CY) parameters, but Cox–Merz analogy became weakened. Besides, melt‐elasticity in terminal region and relaxation time (t_c) in crossing point increased, indicating an enhancement in quasi‐solid behavior of molten PP. Comparing with the elastomers, rheological behaviors of molten PP were more influenced with adding the rigid fillers, especially with W due to distinct acicular shape of W particles. SEBS‐g‐MA elastomer more affected rheological behaviors of the ternary composites than SEBS elastomer, implying that SEBS elastomer and the filler particles behaved individually (i.e., development of separate microstructure) in (PP/GB)/SEBS and (PP/W)/SEBS ternary composites, but core‐shell microstructure developed with strong interfacial adhesion by adding SEBS‐g‐MA elastomer, and the filler particles encapsulated with the thick SEBS‐g‐MA elastomer interlayer (i.e., core‐shell particles) acted like neither big elastomer particles nor like individual rigid particles in melt‐state. Moreover, effects of SEBS‐g‐MA elastomer reached a maximum on rheological behaviors of (PP/W)/SEBS‐g‐MA ternary composite, indicating a synergy between core‐shell microstructure and acicular W particles. Correlations between oscillatory‐shear flow properties and microstructures of the blends and composites were evaluated using Cole–Cole (CC), Han–Chuang (HC), and van Gurp–Palmen (vGP) plots. COMPOS., 2012. © 2012 Society of Plastics     

SBS and SEBS block copolymers as impact modifiers for polypropylene compounds

Blends of polypropylene (PP) and thermoplastic elastomers (TPE), namely SBS (styrene‐butadiene‐styrene) and SEBS (styrene‐ethylene/1‐butene‐styrene) block copolymers, were prepared to evaluate the effectiveness of the TPE type as an impact modifier for PP and influence of the concentration of elastomer on the polymer properties. Polypropylene homopolymer (PP‐H) and ethylene–propylene random copolymer (PP‐R) were evaluated as the PP matrix. Results showed that TPEs had a nucleating effect that caused the PP crystallization temperature to increase, with SBS being more effective than SEBS. Microstructure characterization tests showed that in most cases PP/SEBS blends showed the smallest rubber droplets regardless of the matrix used. It was seen that SEBS is a more effective toughening agent for PP than SBS. At 0°C the Izod impact strength of the PP‐H/SEBS 30% b/w blend was twofold higher than the SBS strength, with the PP‐R/SEBS 30% b/w blend showing no break. A similar behavior on tensile properties and flexural modulus were observed in both PP/TPE blends. Yield stress and tensile strength decreased and elongation at break increased by expanding the dispersed elastomeric phase in the PP matrix. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 254–263, 2005     

mPE弹性体增韧改性PP力学性能的研究

用茂金属聚乙烯（mPE)弹性体代替传统的弹性体,对聚丙烯（PP）的增韧改性进行了研究。探讨了橡塑比和mPE的牌号对共混物力学性能的影响;并对不同的弹性体的增韧效果做了对比研究。结果表明,与传统的弹性体相比,mPE增韧改性的PP显示出卓越的低温冲击性能。     

Melt rheological properties of polypropylene/SEBS (styrene–ethylene butylene–styrene block copolymer) blends

Study of melt rheological properties of the blends of polypropylene (PP) with styrene–ethylene butylene–styrene block copolymer (SEBS), at blending ratios 5–20% SEBS, is reported. Results illustrate the effects of (i) blend composition and (ii) shear rate or shear stress on melt viscosity and melt elasticity and the extrudate distortion. In general, blending of PP with SEBS results in a decrease of its melt viscosity, processing temperatures, and the tendency of extrudate distortion. However, the properties depend on blending ratio. A blending ratio around 5–10% SEBS seems optimum from the point of view of desirable improvement in processability behavior.     

Mechanical properties and morphology of impact modified polypropylene–wood flour composites

The mechanical properties and morphology of polypropylene/wood flour (PP/WF) composites with different impact modifiers and maleated polypropylene (MAPP) as a compatibilizer have been studied. Two different ethylene/propylene/diene terpolymers (EPDM) and one maleated styrene–ethylene/butylene–styrene triblock copolymer (SEBS–MA) have been used as impact modifiers in the PP/WF systems. All three elastomers increased the impact strength of the PP/WF composites but the addition of maleated EPDM and SEBS gave the greatest improvements in impact strength. Addition of MAPP did not affect the impact properties of the composites but had a positive effect on the composite unnotched impact strength when used together with elastomers. Tensile tests showed that MAPP had a negative effect on the elongation at break and a positive effect on tensile strength. The impact modifiers were found to decrease the stiffness of the composites. Scanning electron microscopy showed that maleated EPDM and SEBS had a stronger affinity for the wood surfaces than did the unmodified EPDM. The maleated elastomers are, therefore, expected to form a flexible interphase around the wood particles giving the composites better impact strength. MAPP further enhanced adhesion between WF and impact-modified PP systems. EPDM and EPDM–MA rubber domains were homogeneously dispersed in the PP matrix, the diameter of domains being between 0.1–1 μm. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1503–1513, 1998     

Microstructural characteristics of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers

Microstructural characteristics of isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and dynamic mechanical analyses (DMA) showed that the iPP/SEBS and iPP/SEBS‐g‐MA blends were partially compatible two‐phase systems. Well‐dispersed spherical GB and acicular W particles without evidence of interfacial adhesion were observed in the iPP/GB and iPP/W binary composites respectively. Contrary to the blends, melt flow rates of the iPP/GB and PP/W composites decreased more with SEBS‐g‐MA than with SEBS because of enhanced interfacial adhesion with SEBS‐g‐MA elastomer. The SEM analyses showed that the ternary composites containing SEBS exhibited separate dispersion of the rigid filler and elastomer particles (i.e., separate microstructure). However, SEBS‐g‐MA elastomer not only encapsulated the spherical GB and acicular W particles completely with strong interfacial adhesion (i.e., core‐shell microstructure) but also dispersed separately throughout iPP matrix. In accordance with the SEM observations, the DSC and DMA revealed quantitatively that the rigid filler and SEBS particles in iPP matrix acted individually, whereas the rigid filler particles in the ternary composites containing SEBS‐g‐MA acted like elastomer particles because of the thick elastomer interlayer around the filler particles. The Fourier transform infrared analyses revealed an esterification reaction inducing the strong interfacial adhesion between the SEBS‐g‐MA phase and the filler particles. POLYM. COMPOS., 31:1265–1284, 2010. © 2009 Society of Plastics Engineers     

Effect of maleated polypropylene and impact modifiers on the morphology and mechanical properties of PP/Mica composites

Composites of polypropylene (PP) with mica powder and impact modifiers were produced by internal mixer. A major drawback in the use of mica‐filled PP is its low impact resistance. In the present study, the effect of the maleated PP (MAPP) and impact modifiers was evaluated on the composite properties separately and together. Thus, two different styrene‐ethylene/butylene‐styrene triblock copolymers (SEBS) and one ethylene‐propylene‐diene terpolymer (EPDM) have been used as impact modifiers in the PP‐mica composites. Addition of MAPP had a negative effect on the composite notched impact strength and elongation at break but had a positive effect on tensile strength when used together with impact modifiers. All three elastomers increased the impact strength of the PP‐mica composites but the addition of maleated SEBS (SEBS‐MA) granted the greatest improvement in impact strength. It was inferred from the scanning electron microscopy that SEBS‐MA had a stronger interaction with mica surface than the other impact modifiers. POLYM. COMPOS., 27:614–620, 2006. © 2006 Society of Plastics Engineers     

Highly transparent thermoplastic elastomer from isotactic polypropylene and styrene/ethylene‐butylene/styrene triblock copolymer: Structure‐property correlations

Polypropylene (PP) is one of the most useful general purpose plastics. However, the poor transparency and brittleness of PP restricts its applications in the field of medical and personal care where silicone and polyvinyl chloride (PVC) are presently used. This work concentrates on developing highly transparent elastomeric PP blends and also thermoplastic elastomer by blending isotactic polypropylene (I‐PP) with styrene/ethylene‐butylene/styrene (SEBS) triblock copolymer. PP/SEBS blend derived from high melt flow index (MFI) PP and high MFI SEBS exhibit remarkable transparency (haze value as low as 6%) along with good percentage of elongation and processability. The reduction in difference of refractive index (RI) between PP and SEBS has been observed by blending SEBS with PP. The wide angle X‐ray diffraction studies show that there is significant reduction in the percentage crystallinity of PP by the addition of SEBS block copolymer. Temperature‐dependent polarized light microscopy studies reveal the reduction in spherulites size by the addition of SEBS block copolymer. Transmission electron micrographs show that the SEBS polymer forms a fine lamellar structure throughout the PP matrix with phase inversion at higher SEBS concentration. Development of phase morphology, crystalline morphology, and crystallinity in different blends has been analyzed and microstructure‐haze correlations have been developed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

充油SEBS/PP/PS力学性能的研究

以PP、PS为改性剂对充油SEBS进行了改性。研究结果表明:加入PP时,材料的拉伸强度、熔体流动速率和压缩永久变形增大,但其断裂伸长率迅速下降,回弹性逐渐降低;加入PS时,材料的最佳综合性能为硬度54A,拉伸强度16.75MPa,断裂伸长率740%,熔体流动速率0.159g/10min,回弹性64%。