螺杆组合对PP改性的SEBS弹性体结构与性能的影响

通过螺杆组合设计,考察了反向螺纹元件、密炼转子对苯乙烯-乙烯/丁烯-苯乙烯(SEBS)聚/丙烯(PP)弹性体材料的力学性能、微观形态结构的影响。研究结果表明:通过设计螺杆组合,在适应于塑料加工的双螺杆组合中增加捏合块,引入密炼转子,可使SEBS/PP弹性体材料的拉伸性能、回弹性能等有明显的改善。通过力学性能与结构表征,证明了密炼转子模块对SEBS与PP均匀共混加工的作用。     

SEBS对PP耐辐射性能的影响

以共聚医用聚丙烯(PP)为基材,用氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)对其进行增韧改性,研究了在γ射线辐射下,SEBS对PP耐辐射性能的影响。材料的耐辐射性能通过辐射前后力学性能的变化来评价。研究结果表明:PP基材经过40 kGy辐射后,其断裂伸长率和冲击强度明显降低,分别从651．2％和4．35 kJ／m2下降到 189．8％和3．01 kJ／m2;SEBS的加入可以显著提高PP的耐辐射性能;不同配比的PP／SEBS体系,其耐辐射性能和后期效应不同,PP／SEBS质量配比为90:10时,共混物的耐辐射性能最佳,材料的综合性能可以满足实际应用需求。     

玻纤增强聚苯醚/聚丙烯复合材料的制备及其性能研究

研究了相容剂马来酸酐接枝苯乙烯-乙烯/丁烯-苯乙烯(SEBS-g-MAH)、马来酸酐接枝聚丙烯(PP-gMAH)、苯乙烯-乙烯/丁烯-苯乙烯(SEBS)以及三者的复配对玻纤增强聚苯醚(PPE)/PP共混物的力学性能、热性能及加工性能的影响,并用扫描电子显微镜观察了共混体系的形态结构。结果表明,PP-g-MAH与SEBS复配使用可以有效地改善PPE/PP/玻璃纤维共混体系的相容性,提高了复合材料的力学性能和加工性能,但复配相容剂的添加量不宜过大,当其质量分数为8%时,复合材料的综合性能最为优异。     

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。     

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...     

SEBS、PP与PLA的共混改性及加热不燃烧烟气降温应用

将氢化苯乙烯-丁二烯嵌段共聚物(SEBS)和聚丙烯(PP)与(聚乳酸) PLA共混改性,得到改性复合材料。分析复合材料的物理性能和力学性能,并将复合材料应用于加热不燃烧烟气降温。结果表明,两者均未改变PLA的晶型结构,且SEBS比PP更能增强PLA韧性、拉伸性能和冲击强度,但共混材料分解能力有所下降。SEBS+PLA复合材料具有更好的纺丝性能和加热不燃烧烟气降温效果。     

接枝共混物和PBT对SEBS/PP体系的复合作用

研究了马来酸酐接枝聚乙烯、乙烯-醋酸乙烯酯共混物,聚对苯二甲酸丁二醇酯(PBT)二者对苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)/聚丙烯(PP)体系的复合作用;通过扫描电子显微镜、微机控制电子万能试验机分析了材料的显微组织形貌,测试了材料的力学性能,并用一组验证试验证明了复合作用的存在。结果表明,接枝共混物和PBT二者对SEBS/PP体系产生了一种复合作用,这种复合作用能显著提高SEBS/PP体系的拉伸性能,当接枝共混物、PBT各占体系的10%时,拉伸性能最佳。     

PP/HDPE/弹性体三元共混改性的研究

用双螺杆挤出机制备了聚丙烯(PP)/高密度聚乙烯(HDPE)/弹性体三元共混物,分别探讨了3种弹性体乙烯-辛烯嵌段共聚物(OBC)、苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)、苯乙烯-乙烯/丁烯-苯乙烯嵌段共聚物(SEBS)的含量对PP三元共混物力学性能的影响,并通过扫描电子显微镜观察其脆断表面形态。结果表明,OBC、SBS、SEBS和HDPE都对PP起到了一定的协同增韧作用,SEBS对PP的增韧效果最佳;SEM表明三元共混力学性能与相形态密切相关;所制备的PP/HDPE/OBC三元共混物的加工性能较好。     

PP／Exact共混体系耐辐射性能的研究

以共聚医用聚丙烯(PP)为基材,用茂金属催化的多功能性乙烯和α烯烃共聚物弹性体(Exact)对其进行增韧改性,研究了在γ射线辐射条件下,Exact对PP耐辐射性能的影响,并比较了PP/Exact和PP/SEBS两种共混体系的耐辐射性能,材料的耐辐射性能通过辐射前后材料力学性能的变化来评价。结果表明：添加Exact后,PP的耐辐射性能和后期效应有明显提高。为了保证材料的使用性能,PP/Exact共混体系中Exact含量为25%时,PP的耐辐射效果最佳；SEBS对PP的耐辐射改性效果优于Exact。     

共混顺序对石墨烯微片在PP/PA6/SEBS共混物中的选择性分布和迁移的影响

研究了聚丙烯(PP)/聚酰胺6(PA6)/氢化苯乙烯-丁二烯嵌段共聚物(SEBS)/石墨烯微片(GNPs)纳米复合材料在不同共混顺序下的微观形貌、导电及导热性能,分析了GNPs在复合体系中的选择性分布和迁移及其对复合材料性能的影响.结果表明,在PP/PA6/SEBS/GNPs共混体系中,GNPs在界面张力的作用下趋向于...     

The influence and mechanism of elastomer types on electrical and mechanical properties of polypropylene insulation materials for high voltage cables

Polypropylene (PP) becomes a superior candidate material for new environmentally friendly cable main insulation with its excellent heat resistance, electrical properties, and degradability. However, in practical application, PP material is aging and vulnerable and its toughness is poor. The mechanical properties of PP material can be improved by elastomer modification, but the effects of different elastomers on the comprehensive properties of composite specimens are quite different. In this paper, the electrical and mechanical properties of different types of elastomer-modified PP composites are compared and analyzed by combining experimental and molecular simulation (MS) methods. The experimental results show that the SEBS/PP composite material has the lowest trap energy levels among all kinds of composite materials, its space charge accumulation is 1.96 × 10⁻⁹C, and the mechanical and rheological properties improvement of the composite is the most remarkable. Meanwhile, the volume resistivity is reduced by two orders of magnitude compared with pure PP. However, the breakdown strength of all kinds of composite materials decreases by different degrees after the modification. The solubility parameters (δ) and the free volume are further investigated by the molecular simulation, which shows that the δ of SEBS is similar to that of PP, which represents the best compatibility. Moreover, the SEBS/PP composite material has the strongest inter-molecular force and the most excellent toughness improvement for PP. This work provides a theoretical basis for elastomer selection in PP modification.     

Toughening of polypropylene with styrene/ethylene‐butylene/styrene tri‐block copolymer: Effects of mixing condition and elastomer content

The effect of processing conditions and elastomer content on the toughening of Polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene tri‐block copolymer (SEBS) in a twin‐screw extruder has been investigated. The parameters analyzed were: temperature profile, screw speed, and feed rate of the blend components. Their effect was evaluated through the mechanical properties (tensile strength and Izod impact resistance at room temperature) as well as the morphology of the dispersed phase by means of scanning electron microscopy (SEM). The results showed that the impact resistance increases with increasing rotor speed and feed rate and decreases when the temperature profile is increased. The parameter with the greatest effect on the mechanical properties was the variation in rotor speed. Despite the fact that impact resistance as high as 25 times that of neat PP has been achieved with blends containing 20 wt % SEBS, no significant modification in phase morphology has been observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2185–2193, 2001     

聚乙二醇共混体系的研究进展

综述了近年来聚乙二醇（PEG）共混改性体系的研究进展以及应用情况,对其发展前景进行了展望。PEG与高分子材料混容性好,是应用很广的共混改性材料。PEG共混材料大多采用溶液共混法、熔融共混法和化学交联法制备。采用PEG共混改性其他材料一方面可改善脆性,提高抗冲击性能,另一方面也可提高材料的亲水性和水溶性。     

酚醛摩擦材料研究进展

通过化学改性和共混改性的方法,可有效提高酚醛树脂的耐热性、韧性和摩擦性,从而使酚醛制品满足摩擦材料的多种应用需要。从化学改性、共混改性及多种组分改性等方面对酚醛摩擦材料的研究进展进行了综述。并指出多种组分改性(包括化学改性剂、塑料、橡胶、纤维、金属粉体、无机物纳米粉体等)是今后的研究趋势,在提高酚醛材料摩擦性能的同时对其耐高温性、力学性能等同时进行改良是今后的发展方向。     

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.     

PA／PP／SEBS三元合金的结构与性能

本文作者采用氢化ＳＢＳ（ＳＥＢＳ）三嵌段热塑性弹性体增韧ＰＡ／ＰＰ共混体系，应用挤出反应技术在双螺杆挤出机内就地产生相容剂，可改善体系的相容性，从而获得了超高韧性的尼龙合金，还采用ＳＥＭ和ＴＥＭ技术研究了此类体系的形态结构特征，这些形态结构为进一步研究结构与性能关系提供了丰富的资料。     

天然杜仲胶的改性及应用研究进展

杜仲胶（EUG）主要由反式聚异戊二烯组成,是一种具有良好生物相容性、橡塑二重性和优异力学性能的天然高分子材料。近年来,EUG在新型生物基材料领域备受瞩目。EUG在室温下结晶度高,表现为刚性塑料状态,极大程度限制了其在功能材料领域的应用。因此,将EUG进行物理或化学改性,进而拓宽其应用范围已成为近年来的研究热点。本文详细介绍了EUG分子链结构特点,随后从物理改性和化学改性两个方面系统论述了EUG常见的改性方法及机理,如通过与其它材料共混或环氧化改性、硫化改性等改变EUG的硬度及弹性。对EUG在绿色轮胎与公路建设、形状记忆与自修复材料、减震与吸声材料、医用材料、生物降解复合材料等新型功能材料领域的最新研究进展进行了综述,并在此基础上展望了EUG在生物基高性能材料领域的发展前景。     

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     

SEBS在PP共混物中的研究进展

综述了氢化苯乙烯－丁二烯－苯乙烯嵌段共聚物作为塑料改性剂和共混相容剂，在聚丙烯及其共混物中对共混体系的屈服，冲击，断裂力学等性能的影响及研究进展。     

Evaluation of mechanical properties of polypropylene/polycarbonate/SEBS ternary polymer blends using Taguchi experimental analysis

In this work, ternary polymer blends based on polypropylene (PP)/polycarbonate (PC)/poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) (SEBS) triblock copolymer and a reactive maleic anhydride grafted SEBS (SEBS‐g‐MAH) at fixed compositions are prepared using twin‐screw extruder at different levels of die temperature (235‐245‐255°C), screw speed (70‐100‐130 rpm), and blending sequence (M1‐M2‐M3). In M₁ procedure, all of the components are dry blended and extruded simultaneously using Brabender twin‐screw extruder, whereas in M₂ procedure, PC, SEBS, and SEBS‐g‐MAH minor phases are first preblended in twin‐screw extruder and after granulating are added to PP continuous phase in twin‐screw extruder. Consequently, in M₃ procedure, PP and SEBS‐g‐MAH are first preblended and then are extruded with other components. The influence of these parameters as processing conditions on mechanical properties of PP/PC/SEBS ternary blends is investigated using L9 Taguchi experimental design. The responding variables are impact strength and tensile properties (Young's modulus and yield stress), which are influenced by the morphology of ternary blend, and the results are used to perform the analysis of mean effect as well. It is shown that the resulted morphology, tensile properties, and impact strength are influenced by extrusion variables. Additionally, the optimum processing conditions of ternary PP/PC/SEBS blends were achieved via Taguchi analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010