固相剪切碾磨制备HDPE/WTR共混体系的结构与性能

采用磨盘碾磨废旧轮胎橡胶(WTR)/乙烯-醋酸乙烯酯(EVA)复合粉体与高密度聚乙烯(HDPE)熔融共混制备HDPE/WTR共混物,研究磨盘碾磨对HDPE/WTR共混物的形貌结构、结晶行为、流变行为及力学性能的影响。结果表明:WTR与EVA经磨盘碾磨后所得的复合粉体与HDPE熔融共混过程中形成EVA包覆WTR结构,同时WTR颗粒在基体树脂中的分散性及橡塑两相界面的相容性得到改善。此外,磨盘碾磨还能提高HDPE/WTR共混物的结晶温度及结晶度,改善共混物熔体的加工流动性,同时会降低共混物的弹性与黏性。磨盘碾磨与引入的EVA之间存在显著的协效作用,二者协同使用可大幅改善HDPE/WTR共混物的力学性能,如采用碾磨32次复合粉体制备的共混物拉伸强度、断裂伸长率、缺口冲击强度相较未碾磨样品分别提高31.2%、1500%和51.8%。     

PP/SBS/滑石粉三元复合材料性能研究

通过熔融共混制备了不同滑石粉(经偶联剂KH550表面改性)用量的聚丙烯(PP)/丁苯热塑性弹性体(SBS)/滑石粉复合材料(PP与SBS的配比固定为90/10),同时研究了该复合材料的力学性能和流动性能。结果表明:随着滑石粉用量的增加,PP/SBS/滑石粉复合材料的弹性模量和拉伸强度下降;弯曲性能、冲击性能和熔体流动速率则先提高后降低,且均在滑石粉用量为10份时达到最大值;另外添加了改性滑石粉的PP/SBS/滑石粉复合材料,其拉伸强度、冲击强度和熔体流动速率均高于未改性滑石粉填充的复合材料。     

PP／SBS／纳米CaCO3复合材料结构与性能研究

研究了PP/SBS/纳米CaCO3复合材料的力学性能以及SBS分散相颗粒和纳米CaCO3粒子在PP基体中的分散状况。结果表明,纳米CaCO3粒子的加入使复合材料的缺口冲击强度、弯曲弹性模量、拉伸强度均得到提高。透射电镜观察发现,纳米CaCO3粒子的加入使复合体系的熔体黏度增大,对弹性体SBS的分散起到剪切细化、均化的作用,从而起到协同增韧效应。     

纳米CaCO3增韧聚丙烯的研究

采用熔融共混以及先混炼再熔融共混的方法制备了PP／纳米CaO3及PP聚物（PPR）／SBS／纳CaCO3和合材料。通过SEM，TEM及力学性能测试研究了复合材料的力学性能及CaCO3粒子的分散状况。结果表明，当CaCO3子的质量分数分别为4％和8％，两种共混体系的冲击强度达到最大值，分别为5.18kJ/m^2和59.14kJ/m^2;CaCO3粒子在体系中能够达到纳米级分散。复合材料的冲击断面观察证明材料的增韧是由于基体发生屈服所致。     

PP/PS/SBS共混物的性能研究

通过添加聚苯乙烯(PS)、热塑性弹性体苯乙烯-丁二烯-苯乙烯共聚物(SBS),以改善聚丙烯(PP)的性能。先采用熔融法制备PP/PS共混物,在确定PP,PS最佳配比的基础上,再添加SBS制备PP/PS/SBS共混物,确定了PP,PS及SBS的最佳配比。研究了PP/PS,PP/PS/SBS共混物的力学性能、热性能及熔体流动行为。结果表明,当PP与PS的质量比为70∶30时,PP/PS共混物的性能最好,其拉伸强度为28.5 MPa,拉伸弹性模量为1 214 MPa,弯曲弹性模量为1 752 MPa,冲击强度为14.0 kJ/m2,断裂应变为130%,维卡软化温度为143.9℃。当PP,PS及SBS的质量比为70∶30∶10时,PP/PS/SBS共混物的性能最好,其拉伸强度为23.2 MPa,拉伸弹性模量1 040 MPa,断裂应变为260%,冲击强度为18.0 kJ/m2,弯曲强度为36.5 MPa,弯曲弹性模量为1 297 MPa,定挠度弯曲应力为36.1 MPa,弯曲破坏应力为36.5 MPa,熔体流动速率为8.94 g/(10 min),维卡软化温度为139.0℃。     

PP／POE／纳米CaCO3复合材料的制备与性能研究

采用逐级分散共混法，制备了PP/POE／纳米CaCO3复合材料，研究了其力学性能和微观结构。逐级分散法先制备纳米CaCO3母料，然后将PP分多次加入含纳米CaCO3的共混体系中，目的在于改善纳米CaCO3的分散，以提高复合材料的力学性能。研究结果表明：采用逐级分散法制备的PP/POE／纳米CaCO3复合材料的冲击强度为64．2kJ／m^2，比直接共混法高16．9％，比通常的母料法高9．7％。复合材料的微观结构研究表明：纳米CaCO3粒子基本上都分布在连续相PP中。     

SBS和纳米SiO2协同增韧增强PP复合材料的研究

将热塑性弹性体苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)及纳米Si O2同时添加到聚丙烯(PP)中,以期在熔融共混过程中发挥SBS与纳米Si O2的协同增强增韧作用,达到有效改善PP综合性能的目的。用硬脂酸(SA)对纳米Si O2粒子表面进行功能化包覆改性,再经熔融共混技术制备了PP/SBS/纳米Si O2复合材料,研究了纳米Si O2表面处理效果及其用量对复合材料力学性能、流变性能及热性能的影响。力学性能研究结果表明,纳米Si O2与SBS对PP具有明显的协同增强增韧作用。当纳米Si O2质量分数为3.84%时,PP/SBS/纳米Si O2复合材料的综合性能最佳,其拉伸强度、断裂强度和拉伸弹性模量分别为37.4,23.8,129.9 MPa,室温(25℃)断裂强度比纯PP提高了100%;其室温和–20℃下缺口冲击强度分别较纯PP提高了51.5%和66.7%。微观形貌分析表明,熔融共混过程中,纳米Si O2均匀分散于PP基体中,复合材料基体在室温冲击下发生明显塑性变形,导致其冲击韧性明显高于低温冲击韧性。与纯PP相比,PP/SBS/纳米Si O2复合材料的流动性增大,耐热变形性能提高。     

离聚体增容PA1010／SBS共混物的研究

采用磺化丁基胶锌盐(ZnSIIR)离聚体作为PA1010/SBS共混物的增容剂,研究了共混体系的结构、形态、相容性及对材料冲击性能的影响。结果表明,ZnSIIR的加入有效改善了SBS在PA1010中的相容性;对PA1010结晶起成核作用,并加快其结晶速率;共混物缺口冲击强度得到提高,且在PA1010/SBS为90/10、ZnSIIR为SBS的10％左右时效果较佳。     

PP／HDPE／弹性体三元共混体系的力学性能,形态及应用

本文叙述PP/HDPE/弹性体三元共混体系的力学性能、形态特征与组成配比的关系。研究结果表明,PP/HDPE/弹性体三元共混可以制成具有高冲击性能的PP改性材料,常温缺口冲击强度大于40kJ/m~2,其他力学性能较均衡,加工性能良好。HDPE的品种和用量以及弹性体的品种和用量对PP三元共混物的力学性能及形态有较大的影响。实验结果表明,当弹性体用量在20%范围内,组成的PP/HDPE复合基体才能获得高冲击性能的三元共混物。在PP/HDPE共混物内,HDPE对PP球晶起到插入和分割作用,使PP球晶变得不完整,被分割成晶片。当HDPE含量较高时,PP只能生成尺寸较小的结晶碎片(细化),与此形态对应,可获得高冲击强度的PP/HDPE共混物。当弹性体(Ⅰ)掺混于PP/HDPE时,弹性体起着类似于HDPE对PP晶体的插入、分割和细化作用,而且弹性体的这种作用更强于HDPE。文中还简叙了PP三元共混物的应用情况。     

聚丙烯／镧化合物改性超细碳酸钙复合材料的研究

采用熔融共混法制备了聚丙烯/镧化合物改性超细碳酸钙(PP/UCaCO3-La^3 )和聚丙烯/超细碳酸钙(PP/UCaCO3)两种复台材料.力学性能测试表明：复合材料的冲击强度随着填料用量的增加先增后减，拉伸强度则递减.PP/UCaCO3-La^3 的冲击强度高于PP/UCaCO3，可提高至PP的3倍以上?透射电镜和扫描电镜分析表明：UCaCO3-La^3 在PP中具有很好的分散性，随着镧化合物用量的增加而进一步改善.DSC分析表明，UCaCO3-La^3 可显著提高复合材料的结晶温度和结晶度，结晶性能的改善是材料冲击强度提高的重要原因.热重分析结果表明：与UCaCO3相比，UCaCO3-La^3 对提高PP热稳定性的贡献更为显著.     

Compatibilization of polypropylene/polystyrene blends with poly(styrene-b-butadiene-b-styrene) block copolymer

The compatibilizing effect of the triblock copolymer poly(styrene-b-butadiene-b-styrene) (SBS) on the morphology and mechanical properties of immiscible polypropylene/polystyrene (PP/PS) blends were studied. Blends with three different weight ratios of PP and PS were prepared and three different concentrations of SBS were used for investigations of its compatibilizing effects. Scanning electron microscopy (SEM) showed that SBS reduced the diameter of the PS-dispersed particles as well as improved the adhesion between the matrix and the dispersed phase. Transmission electron microscopy (TEM) revealed that in the PP matrix dispersed particles were complex “honeycomblike” aggregates of PS particles enveloped and joined together with the SBS compatibilizer. Wide-angle X-ray diffraction (WAXD) analysis showed that the degree of crystallinity of PP/PS/SBS slightly exceeded the values given by the addition rule. At the same time, addition of SBS to pure PP and to PP/PS blends changed the orientation parameters A₁₁₀ and C significantly, indicating an obvious SBS influence on the crystallization process in the PP matrix. SBS interactions with PP and PS influenced the mechanical properties of the compatibilized PP/PS/SBS blends. Addition of SBS decreased the yield stress and the Young's modulus and improved the elongation at yield as well as the notched impact strength in comparison to the binary PP/PS blends. Some theoretical models for the determination of the Young's modulus of binary PP/PS blends were used for comparison with the experimental results. The experimental line was closest to the series model line. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 2625–2639, 1998     

Blends of i‐PP and SBS. II. Influence of in situ compatibilization on the mechanical properties

This article concerns the in situ compatibilization of immiscible isotatic polypropylene/styrene–butadiene–styrene triblock copolymer blends (i‐PP/SBS) by use of a reactive mixture. For this purpose, maleated PP (PP–MAH) and SBS (SBS–MAH) were used as functionalized polymers and 4,4′‐diaminediphenylmethane was used as a coupling agent between maleated polymers, resulting in a graft copolymer. Binary blends of i‐PP/SBS, nonreactive ternary blends of i‐PP/PP–MAH/SBS, and reactive ternary blends of i‐PP/PP–MAH/SBS–MAH with varying diamine/anhydride molar ratios were prepared. The mechanical properties of the blends were determined by tensile and impact‐resistance tests. The optimum improvement in the mechanical properties was found when the diamine/anhydride molar ratio in the ternary reactive blends was 0.5/1. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 516–522, 2003     

SIS/SBS/PP共混改性的研究

研究了新型聚丙烯(PP)合金材料的配方、制备、工艺及性能。分别讨论了不同用量的三元乙丙橡胶 (EPDM)、苯乙烯与异戊二烯嵌段共聚物(SIS)及苯乙烯与丁二烯嵌段共聚物(SBS)与PP组成的二元和三元共混体系对材料力学性能的影响。结果表明:SIS为PP较好的增韧剂,PP／SIS/SBS三元共混体系具有较好的协同效应,在某种程度上可以代替EPDM改性PP,共混改性后拉伸强度、扯断伸长率等性能优良。     

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     

Effect of styrene–isoprene–styrene,styrene–butadiene–styrene,and styrene–butadiene–rubber on the mechanical,thermal, rheological,and morphological properties of polypropylene/polystyrene blends

The mechanical, thermal, rheological, and morphological properties of polypropylene (PP)/polystyrene (PS) blends compatibilized with styrene–isoprene–styrene (SIS), styrene–butadiene–styrene (SBS), and styrene–butadiene–rubber (SBR) were studied. The incompatible PP and PS phases were effectively dispersed by the addition of SIS, SBS, and SBR as compatibilizers. The PP/PS blends were mechanically evaluated in terms of the impact strength, ductility, and tensile yield stress to determine the influence of the compatibilizers on the performance properties of these materials. SIS‐ and SBS‐compatibilized blends showed significantly improved impact strength and ductility in comparison with SBR‐compatibilized blends over the entire range of compatibilizer concentrations. Differential scanning calorimetry indicated compatibility between the components upon the addition of SIS, SBS, and SBR by the appearance of shifts in the melt peak of PP toward the melting range of PS. The melt viscosity and storage modulus of the blends depended on the composition, type, and amount of compatibilizer. Scanning electron microscopy images confirmed the compatibility between the PP and PS components in the presence of SIS, SBS, and SBR by showing finer phase domains. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 266–277, 2003     

Studies on dynamically vulcanized polypropylene (PP)/butadiene styrene block copolymer (SBS) blends: Crystallization and thermal behavior

Crystallization of polypropylene (PP) in unvulcanized blends of PP with the butadiene–styrene block copolymer (SBS) was studied through differential scanning calorimetry (DSC) and X‐ray diffraction measurements in the composition range of 0–40 wt % SBS content. Analysis of the crystallization exotherms revealed variation in the crystallization behavior, crystallinity, and crystalline morphology of the PP component in the blends at various levels of SBS concentration. The crystallinity determined by X‐ray diffraction and DSC showed identical variations with the blend composition. The tensile and thermal properties of the blends were studied in the entire composition range. Correlations of the tensile properties with the crystallization parameters of the PP component in the blends are also presented. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 151–161, 1999     

顺丁烯二酸钾基(苯乙烯-丁二烯-苯乙烯)嵌段共聚物离聚体的力学性能及其应用

用环氧化(苯乙烯-丁二烯-苯乙烯)嵌段共聚物(SBS)开环反应合成了含顺丁烯二酸钾基的SBS离聚体,考察了离子基团不同含量对含顺丁烯二酸钾基的SBS离聚体力学性能的影响,研究了离聚体/聚丙烯(PP)共混物的力学性能和耐溶剂性能,以及离聚体对氯醇橡胶(CHR)/SBS共混物的增容效果。结果表明,该离聚体呈现热塑性弹性体行为;随着离子基团含量的增加,离聚体的拉伸强度及扯断伸长率增大,但当离子基团含量超过1.69mmol/g时,离聚体的力学性能又有所下降,离子基团最佳含量为1.23~1.69mmol/g;该离聚体与PP共混,在拉伸强度方面呈现协同效应;离聚体作为增容剂提高了SBS与CHR的相容性,当离聚体质量分数为3%时,力学性能达到最佳,共混物的耐溶剂性能也得到了改善。     

PP／PE-LLD／SBS共混交联体系的结构与性能研究

采用两步交联法制备PP/PE-LLD/SBS交联共混物。DSC和WAXR测试结果表明,交联作用对共混物组分的结晶度无明显影响;从维卡软化点和TG、DTG曲线可以看出,交联提高了共混物的耐热温度,热稳定性增强;通过DMA测试发现,交联后共混物组分的玻璃化转变温度Tg无明显变化,交联作用对分子链段的运动影响不大;但交联共混物的内耗角tanδ、存储模量Ε′和损耗模量Ε″都有很大提高,刚、韧性增强。交联使共混物的熔体流动速率减小,流动性下降,但仍保持假塑性流体行为,随剪切速率增大出现剪切变稀;交联作用增大了共混物的活化能,分子链间作用力加强,刚性增大,黏度对温度变化更为敏感。     

PP／HDPE／SBS三元共混物的研究——形态结构与性能

研究了PP/HDPE/SBS三元共混物的性能及形态结构特征。研究结果表明,PP三元共混物的冲击韧性除与SBS的含量密切相关外,还与HDPE的含量有关,HDPE起到了与SBS相似的增韧作用。由于HDPE的掺入,减少了SBS的含量,制成了一种力学性能均衡的超高韧性PP三元共混材料。形态结构的研究表明,共混物中,SBS呈颗粒状分布,另外SBS还与HDPE组成了具有包藏结构的复合粒子。     

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