微晶纤维素增强聚丙烯复合材料的制备与力学性能研究

以聚丙烯(PP)为基体、微晶纤维素(MCC)为增强材料、马来酸酐接枝聚丙烯(PP-g-MA)为相容剂,利用双螺杆挤出机制备了PP/MCC/PP-g-MA复合材料,同时研究了该复合材料的力学性能。随后分别选用三元乙丙橡胶(EPDM)和乙烯-辛烯共聚物(POE)对PP/MCC/PP-g-MA复合材料进行增韧改性,考察了两种增韧剂的增韧效果。结果表明:加入PP-g-MA后,PP/MCC复合材料的力学性能明显提高。另外,增韧剂的引入使PP/MCC/PP-g-MA复合材料的冲击性能显著改善,其中POE对复合材料的增韧效果优于EPDM。但是增韧剂的引入会造成复合材料的拉伸强度、弹性模量和弯曲强度分别出现不同程度的下降,其中EPDM增韧复合材料的上述性能下降幅度相对较小。     

阻燃ABS的增韧研究

分别以苯乙烯-丁二烯-苯乙烯共聚物(SBS)、乙烯-1-辛烯共聚物(POE)、三元乙丙橡胶(EPDM)为增韧剂,研究了它们对阻燃丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料力学性能和阻燃性能的影响。结果表明:以SBS为增韧剂所得复合材料的综合性能优于以POE或EPDM为增韧剂所得复合材料;随SBS用量的增大,复合材料的冲击强度提高,当SBS用量为15%时,其冲击强度达到15.91kJ/m2,较未经增韧改性复合材料的冲击强度提高了9.99kJ/m2;并且SBS的加入不会对复合材料的阻燃性能产生不利影响。     

不同增韧剂对玻纤增强液晶聚酯体系性能的影响

以液晶聚酯(LCP)为基体树脂,研究玻璃纤维(GF)添加比例对LCP力学性能的影响,确定LCP/GF=70/30的比例为增强效果最优一组。在LCP/GF(70/30)体系中分别加入弹性体增韧剂马来酸酐接枝三元乙丙橡胶(EPDM–g–MAH)、马来酸酐接枝乙烯–辛烯共聚物(POE–g–MAH)、马来酸酐接枝加氢苯乙烯–丁二烯–苯乙烯共聚物(SEBS–g–MAH)、韧性好模量低的增韧树脂茂金属聚乙烯(m PE)及刚性粒子Ca CO3,探索不同增韧剂体系对LCP/GF体系力学性能的影响。研究结果表明,弹性体类增韧剂对LCP/GF体系力学性能的提升效果较为显著,其次为m PE,而适当使用刚性粒子Ca CO3可起到对体系既增强又增韧的作用。当LCP/GF基体为100份,增韧剂EPDM–g–MAH添加量为15份时,其增韧效果最优,冲击性能可提升24%。     

家具用PP基木塑复合材料的制备与力学性能

以聚丙烯(PP)为木塑复合材料基体,分别加入4种增强剂和3种增韧剂,通过共混挤出制备PP基木塑复合材料,研究了4种增强剂含量和粒径以及3种增韧剂含量对复合材料力学性能的影响。结果表明,随着增强剂含量增加,复合材料的弯曲强度表现出先升后降趋势,随着增强剂粒径减小,复合材料的弯曲强度提高,增强效果从高到低依次为硅灰石、滑石粉、碳酸钙和硫酸钡;当硅灰石粒径为10μm、质量分数为15%时,复合材料具有最优的拉伸、弯曲以及缺口冲击强度。增韧剂乙烯–辛烯共聚物(POE)、三元乙丙橡胶(EPDM)和苯乙烯–丁二烯–苯乙烯共聚物(SBS)可以大幅提高复合材料的缺口冲击强度,增韧效果从高到低依次为POE,EPDM和SBS。当粒径为10μm的硅灰石和POE质量分数分别为15%和20%时,复合材料综合力学性能最好,缺口冲击强度为17.61 k J/m2、拉伸强度为27.65 MPa、弯曲强度为30.28 MPa,其弯曲强度优于目前常用木质人造板材,可满足家具行业应用。     

增韧剂对PC/PBT合金性能的影响

研究了三种不同类型增韧剂乙烯–丙烯酸丁酯–甲基丙烯酸缩水甘油酯共聚物(PTW)、甲基丙烯酸甲酯–丁二烯–苯乙烯共聚物(MBS)和乙烯–辛烯共聚物(POE)对聚碳酸酯/聚对苯二甲酸丁二酯(PC/PBT)合金力学性能、熔体流动速率(MFR)、热性能和结晶与熔融行为的影响。结果表明:对于PC/PBT (质量比为65/35)合金,当增韧剂添加量为5份时,PC/PBT合金综合性能最优。三种类型的增韧剂都能显著改善PC/PBT合金的冲击性能,当增韧剂添加量在2～5份时,PC/PBT合金发生脆韧转变。MBS增韧PC/PBT合金的拉伸强度和弯曲强度保持率最高,分别为94.0%和92.6%,但热变形温度降低到105.7℃;PTW增韧PC/PBT合金的拉伸强度和弯曲强度保持率最低,分别为84.3%和80.7%,其优势是对热变形温度基本无影响,但对PC/PBT合金MFR的降低最严重;PTW和POE增韧PC/PBT合金的耐湿热老化性远优于MBS增韧PC/PBT合金。三种类型的增韧剂对PC/PBT合金中的PBT相结晶性均有不同程度的阻碍作用,MBS增韧PC/PBT合金的结晶度最高,为35.73%,POE增韧PC/PBT合金的结晶度为30.21%,PTW增韧PC/PBT合金的结晶度最低,为24.95%。     

HDPE增韧PP-R/石墨复合材料力学性能的研究

采用高密度聚乙烯(HDPE)为增韧剂、乙烯 丙烯 二烯三元共聚物(EPDM)、乙烯 辛烯共聚物(POE)为相容剂、石墨为功能性助剂制备了以无规共聚聚丙烯(PP R)或嵌段共聚聚丙烯(PP B)为基体的PP R或PP B／HDPE／石墨复合材料。详细研究了HDPE含量、弹性体种类及含量对PP R或PP B／HDPE／石墨复合材料力学性能的影响。结果表明HDPE用量在20%、EPDM含量为5%时,PP R或PP B复合材料力学性能优异;POE可以实现PP R或PP B／HDPE／石墨复合材料力学性能的平衡。     

耐热高韧汽车保险杠用OBC增韧PP专用料研究

以嵌段共聚聚丙烯(PP–B)为基体,乙烯–辛烯嵌段共聚物(OBC)为增韧剂,通过添加质量分数为15%的滑石粉及其它助剂,采用双螺杆挤出机制备了OBC增韧PP–B汽车保险杠专用料。研究了OBC和乙烯–辛烯无规共聚物(POE)的用量对专用料力学性能和热变形温度(HDT)的影响。结果表明,OBC可使PP–B晶区细化,与POE相比,其增韧的专用料具有更高的常、低温缺口冲击强度、弯曲强度和HDT,拉伸强度和断裂伸长率则相差不大。当OBC质量分数为20%时,其增韧的专用料在23℃和-20℃的缺口冲击强度分别为64.3,52.7 k J/m2,弯曲强度为38.8 MPa,HDT为105℃,与相同用量下POE增韧的专用料相比分别提高了28.3%,28.9%,24.4%和23.5%。     

PP/POE及PP/EPDM共混改性研究

以茂金属聚烯烃弹性体(POE,乙烯-辛烯共聚物)和三元乙丙橡胶(EPDM)作为聚丙烯(PP)的增韧剂,研究了PP/POE及PP/EPDM共混物的加工性能及力学性能。研究结果表明,POE在加工性、增韧改性等方面比EPDM更具有优势。借助扫描电子显微镜(SEM)进一步探讨了共混物的形态结构与性能的关系。     

POE与EPDM对聚丙烯增韧改性研究

以茂金属聚烯烃弹性体(POE,乙烯-辛烯共聚物)和传统三元乙丙胶(EPDM)作为聚丙烯(PP)的增韧剂,比较研究了PP/POE及PP/EPDM共混物的加工性能及力学性能。研究结果表明,POE在加工性、增韧改性等方面比EPDM更具有优势。扫描电子显微镜(SEM)进一步探讨了共混物的形态结构与性能的关系。     

不同增韧剂对丙烯腈-苯乙烯共聚物耐候性的影响

采用7种增韧剂:高胶粉、丙烯酸酯类树脂(ACR),马来酸酐接枝三元乙丙橡胶(EPDM–g–MAH),苯乙烯三元共聚物(MBS),乙烯丙烯酸丁酯(EBA),马来酸酐接枝低密度聚乙烯(PE–LD–g–MAH),乙烯–甲基丙烯酸酯(EMA)对丙烯腈-苯乙烯共聚物(SAN)进行增韧改性,通过高低温实验箱和氙灯人工气候试验箱来研究各增韧剂对SAN耐候性的影响。结果表明,添加增韧剂MBS的SAN冲击强度最高;随着温度的降低,SAN的冲击强度是下降的,EBA,EPDM–g–MAH能改善SAN的低温冲击强度;氙灯光照老化试验结果表明,SAN经过光照老化后都会出现黄变现象,而添加了EPDM–g–MAH,MBS,EBA的SAN的耐光照老化性能都有所提高,其中添加了EPDM–g–MAH的耐光照老化性最好。     

新型热塑性弹性体增韧聚丙烯的研究

以聚烯烃弹性体(POE,乙烯-辛烯共聚物)为PP的增韧性剂,利用转矩流变仪、差示量热扫描(DSC)及力学性能测试方法,比较研究了PP/POE及PP/EPDM共混物的加工性能、结晶性能及力学性能;结果表明,POE在加工性、改性效果等方面比EPDM更具优势。还探讨了POE用量对PP/CaCO     

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.     

EPDM/POE/PP热塑性硫化橡胶材料的制备及性能研究

以三元乙丙橡胶(EPDM)/乙烯-辛烯共聚物(POE)/聚丙烯(PP)为原料,在PP含量固定的情况下,将POE部分取代EPDM,采用动态硫化技术制备出EPDM/POE/PP三元热塑性橡胶材料(TPV),研究不同含量的POE对材料力学性能、流变性能和微观形貌的影响。结果显示,随着POE含量的增加,三元TPV材料的硬度和熔体质量流动速率不断增大;拉伸强度和断裂伸长率呈线性增大,当EPDM/POE/PP比例为45/40/15时,材料力学性能达到最大值。流变性能和微观形貌分析结果表明,EPDM/POE/PP三元TPV材料具有良好的综合性能。     

Effect of SEBS on morphology, thermal, and mechanical properties of PP/organoclay nanocomposites

A simultaneously increase in stiffness and toughness is needed for improving polypropylene (PP) competitiveness in automotive industry. The aim of this paper is to investigate the effects of styrene-(ethylene-co-butylene)-styrene triblock copolymer (SEBS) on mechanical and thermal properties of PP, in the presence and the absence of nanoclay. The amount of SEBS in PP was ranged to obtain the matrix with the most favorable stiffness–toughness balance. For this purpose, SEBS domain size and distribution in PP/SEBS blends was determined by means of atomic force microscopy and correlated with mechanical properties. The influence of SEBS on the crystalline structure of PP in PP/organoclay nanocomposites was investigated by X-ray diffraction and differential scanning calorimetry, a synergistic effect of SEBS and nanoclay being pointed out. Moreover large improvement in the impact strength (almost 22 times) was obtained in the case of SEBS-containing nanocomposite in comparison with the composite without SEBS.     

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     

不同弹性体增韧聚丙烯的研究

通过双螺杆挤出机制备了三种不同的弹性体EPR、EPDM、POE与PP的共混物,测试了共混物的力学性能, 比较了三种弹性体的增韧效率。结果表明:三种弹性体都是PP有效的增韧剂,其中POE的增韧效率最高,其冲击强度是纯PP的25倍。通过扫描电镜观察了弹性体在PP中的分散,发现POE在基体中相区尺寸最小,其冲击强度最大;EPDM相区尺寸最大,其冲击强度最小,这意味着共混物的相形态与性能有很好的相关性,三种弹性体在PP中分散尺寸不同的主要原因是由于弹性体与PP的黏度比不同引起的。DMA分析表明低模量的弹性体有利于提高共混物的韧性。     

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     

PP/POE/CaCO_3复合材料的性能研究

采用熔融共混工艺制备了聚丙烯/聚烯烃弹性体/碳酸钙(PP/POE/CaCO3)复合材料,研究了POE及CaCO3用量对复合材料力学性能、流变性能及热性能的影响。结果表明:随着POE含量的增加,复合材料的冲击强度显著增大,当POE含量为12%时,冲击强度较纯PP增加233%;同时拉伸强度随POE含量的增加缓慢下降。随着CaCO3含量增加,冲击强度先增加后缓慢下降。     

玻纤增强聚丙烯复合材料性能研究

研究了玻纤(GF)、SEBS和聚丙烯接枝马来酸酐(PP-g-MAH)用量对GF增强聚丙烯复合材料性能的影响,以及PP/GF(65/35)、PP-g-MAH/PP/GF(15/65/35)的微观形态。结果表明:随着GF用量的增加,复合材料的拉伸强度、弯曲强度和弯曲模量增加,断裂伸长率降低,冲击强度先减小后增大,PP/GF复合材料断面呈脆性断裂;在PP/GF中添加增韧剂SEBS可以提高复合材料的冲击强度,但拉伸强度、断裂伸长率、弯曲强度和弯曲模量均减小;在PP/GF中添加增容剂PP-g-MAH,可使其拉伸强度、断裂伸长率、弯曲强度、弯曲模量和冲击强度均得到提高,当PP-g-MAH/PP/GF为15/65/35时,复合材料性能优异,材料断面呈韧性断裂。