HMW—HDPE与LMW—HDPE的共混改性

选用一种高分子量高密度聚乙烯（ＨＭＷ－ＨＤＰＥ）和一种低分子量高密度聚乙烯（ＬＭＷ－ＨＤＰＥ），对它们的共混行为和共混物的热性能、流动性能和力学性能进行了研究。结果表明，在研究的共混比范围内，由ＤＳＣ发现双组分体系可能存在共晶相。ＨＭＷ－ＨＤＰＥ／ＬＭＷ－＝ＨＤＰＥ共混体系的熔体指数基本符合Ａｒｒｈｅｎｉｕｓ粘度加和方程：ＭＩ＝ＭＩ．ＭＩ２。在ＬＭＷ－ＨＤＰＥ质量百分含量为２０％时，共混体系的拉伸     

PP三元共混合金的力学性能及结晶行为研究

研究了不同乙烯含量的ＥＰＤＭ对ＰＰ／ＵＨＭＷＰＥ合金的增容作用,并讨论了共混体系结晶行为的变化情况。发现ＥＰＤＭ中乙烯含量的增加可提高增容效果;在ＰＰ／ＵＨＭＷＰＥ／ＥＰＤＭ为１００／１０／６时,共混物缺口冲击强度可达９１．１ｋＪ／ｍ＾２,为ＰＰ的３．５倍,此时拉伸强度仍比纯ＰＰ高４．３ＭＰａ。     

聚丙烯共混改性研究

将少量（１％）自制的甲基丙烯酸十八醇酯（ＳＭＡ）与丙烯酰胺（ＡＭ）共聚物Ｐ（ＳＭＡ－ＡＭ）添加剂聚丙烯（ＰＰ）中进行共混，能大幅度提高聚丙烯的亲水性和粘合强度。Ｐ（ＳＭＡ－ＡＭ）的加入，改善了ＰＰ的流变性能，对ＰＰ的结晶度和拉伸强度影响不大。俄歇电子能谱（ＡＥＳ）分析表明，Ｐ（ＳＭＡ－ＡＭ）在ＰＰ共混物表面富集。     

HIPS/PP反应共混物的热性能研究

研究了高抗冲聚苯乙烯（ＨＩＰＳ）／聚丙烯（ＰＰ）在过氧化二异丙苯（ＤＣＰ）存在下熔融反应共混物的热学性能,ＨＩＰＳ在ＤＣＰ存在下以ＰＤＳ的降解为主,ＰＳ的Ｔｇ明显下降,ＰＰ在ＤＣＰ存在下以降解为主,ＰＰ的结晶完善性受到破坏,分子运动的特征及热性能较前两者发生明显变化,ＰＳ的Ｔｇ略有下降,ＰＰ分子链的规整性降低,结晶粘点降低,完善性变差。     

LLDPE及VLDPE对LDPE／HDPE共混物拉伸性能的影响

研究了线性低密度聚乙烯（ＬＬＤＰＥ）和极低密度聚乙烯（ＶＬＤＰＥ）对高密度聚乙烯（ＨＤＰＥ）／低密度聚乙烯（ＬＤＰＥ）共混物拉伸性能的影响。由于ＬＬＤＰＥ或ＶＬＤＰＥ的加入，改善了ＨＤＰＥ与ＬＤＰＥ间的相互作用，提高了ＨＤＰＥ／ＬＤＰＥ共混物的拉伸性能。     

增强增韧尼龙66工程塑料结晶行为的研究

采用ＤＳＣ技术,对增强增韧尼龙６６进行了结晶行为的研究。实验结果表明,在合金化改性ＰＡ６６结晶过程中,所填充的玻纤增强剂成核剂作用,而共混低密度聚乙烯、聚丙烯及其马来酸酐接枝物等增韧剂,使成核作用下降,总的成核作用顺序是：ＰＡ／ＧＦ〉ＰＡ／ＧＦ／ＬＤＰＥ－ｇ－ＭＡＨ〉ＰＡ／ＧＦ／ＰＰ〉ＰＡ／ＧＦ／ＰＰｇ－ＭＡＨ。     

紫外线辐照HDPE与尼龙－6共混材料结构与力学性能的研究

研究了紫外线辐照ＨＤＰＥ与ＰＡ６共混材料的微观形态、结晶结构、熔融行为及力学性能。ＳＥＭ、ＷＡＸＤ、ＤＳＣ结果表明，随紫外线辐照时间的增加，共混物中ＰＡ６的粒径减小，与基体作用加强，ＨＤＰＥ晶面间距增大，熔点、结晶度降低，熔程变窄。力学性能测试结果表明，紫外线辐照能明显提高共混材料（ｕＨＤＰＥ／ＰＡ６：９０／１０）的拉伸强度、断裂伸长率、拉伸断裂能和冲击强度。当辐照时间超过１４４ｈ由于ＨＤＰＥ热稳定性明显降低，共混过程中ＨＤＰＥ热降解严重，共混物的韧性突降。     

超高韧半晶聚合物PP多相体系的结构及脆韧转变的研究

通过严格控制工艺条件，得到了不同分散相含量和不同粒径的ＰＰ／ＥＰＤＭ／ＨＤＰＥ和ＰＰ／ＥＰＤＭ共混体。利用ＳＥＭ分析了ＰＰ／ＥＰＤＭ／ＨＤＰＥ的结构特点，通过测量Ｉｚｏｄ缺口冲击强度，得到了ＰＰ／ＥＰＤＭ／ＨＤＰＥ的脆韧转变主曲线，证明其符合脆韧性转变规律；同时利用ＳＥＭ照片，分析了主曲线不同区域的增韧机理。     

HPVC／PP共混改性研究：IV共混物的流变特性

研究了ＨＰＶＣ／ＰＰ共混物的流变性能，结果表明，ＣＰＥ，ＡＢＳ对ＨＰＶＣ／ＰＰ有增粘作用，随着ＣＰＥ用量增加，共混物熔体粘度（η）增加。ＣＰＥ或ＡＢＳ先与ＨＰＶＣ共混后再与ＰＰ共混的共的的η高于ＣＰＥ或ＡＢＳ先与ＰＰ共混后再与ＨＰＶＣ共混的共混物ηＨＰＶＣ／ＰＰ，ＨＰＶＣ／ＰＰ／ＭＡＨ２．５ＨＰＶＣ／ＰＰ／ＣＰＥ１０，ＨＰＶＣ／ＡＢＳ１０共混物的η～组成（Ｃ）的关系均属于正－负偏离共混物（Ｐ－ＮＤ     

HDPE,LLDPE及EPDM对PP非等温结晶行为的影响

采用等速率温ＤＳＣ法研究了ＨＤＰＥ、ＬＬＤＰＥ及ＥＰＤＭ对ＰＰ非等温结晶行为的影响。结果表明，ＰＥ的加入使用ＰＰ的结晶峰温度升高，熔点下降，且使结晶速率加快，球晶细化。ＨＤＰＥ先先ＰＰ结晶，燕促使ＰＰ／ＨＤＰＥ共混物中的ＰＰ异相成核。     

Effect of high density polyethylene addition and testing temperature on the mechanical and morphological properties of polypropylene/ethylene-propylene diene terpolymer binary blends

High density polyethylene (HDPE) was added to the polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM) binary blend, and the effect of testing temperatures on the modulus of elasticity, impact behavior and corresponding fracture morphology was analyzed. Modulus of elasticity generally decreased as the EPDM content increased regardless of the testing temperatures. However, it was found that the modulus of elasticity of PP/EPDM/HDPE ternary blend increased compared to PP/EPDM binary blend when tested at –30 and –60 °C. Notched Izod impact strength changed depending on the testing temperatures, however, there was not much difference between binary and ternary blends up to 20 wt% EPDM. However, at more than 30 wt% EPDM content, ternary blends showed higher impact strength compared to binary blends. Especially, at –30 °C, brittle-ductile transition was observed between 20 and 30 wt% EPDM. Subsurface morphology was also analyzed, and the relationship between the impact strength and the stress whitening zone was investigated. Scanning electron microscopy observation of impact fractured surfaces was conducted, and overall morphology was analyzed with respect to HDPE addition and testing temperature change.     

Elastomer modified polypropylene–polyethylene blends as matrices for wood flour–plastic composites

Blends of polyethylene (PE) and polypropylene (PP) could potentially be used as matrices for wood–plastic composites (WPCs). The mechanical performance and morphology of both the unfilled blends and wood-filled composites with various elastomers and coupling agents were investigated. Blending of the plastics resulted in either small domains of the minor phase in a matrix of major phase or a co-continuous morphology if equal amounts of HDPE and PP were added. The tensile moduli and yield properties of the blends were clearly proportional to the relative amounts of HDPE and PP in the blends. However, the nominal strain at break and the notched Izod impact energies of HDPE were greatly reduced by adding as little as 25% of the PP. Adding an ethylene–propylene–diene (EPDM) elastomer to the blends, reduced moduli and strength but increased elongational properties and impact energies, especially in HDPE-rich blends. Adding wood flour to the blends stiffened but embrittled them, especially the tougher, HDPE-rich blends, though the reductions in performance could be offset somewhat by adding elastomers and coupling agents or a combination of both.     

水镁石短纤维增强HDPE/EPDM 无卤阻燃复合材料的研究

本文着重研究了水镁石短纤维增强HDPE/E PDM 复合材料的力学性能、介电性能以及水镁石短纤维的阻燃效果, 对水镁石短纤维和粒状无卤阻燃剂填充HDPE/E PDM 复合体系的拉伸性能、介电性能和阻燃效果进行了对比研究。并采用动态力学谱、SEM 等方法对该体系的微观结构进行了分析, 结果表明, 水镁石短纤维对复合体系除具阻燃作用外, 还具有显箸的增强作用。     

采用β成核动态硫化PP/EPDM共混物增韧聚丙烯

采用β成核的动态硫化iPP/EPDM共混物即热塑性硫化胶(TPV)改性聚丙烯,并与通用增韧剂聚烯烃弹性体(POE)、三元乙丙橡胶(EPDM)增韧聚丙烯进行比较,考察了增韧体系的力学性能、热性能和相形态.结果表明,随增韧剂含量的增加,增韧体系的拉伸屈服强度和弯曲模量均有所下降,而冲击强度提高.TPV改性体系的强度、模量和...     

Improvement of impact property of natural fiber–polypropylene composite by using natural rubber and EPDM rubber

In this research, vetiver grass was used as a filler in polypropylene (PP) composite. Chemical treatment was done to modify fiber surface. Natural rubber (NR) and Ethylene Propylene Diene Monomer (EPDM) rubber at various contents were used as an impact modifier for the composites. The composites were prepared by using an injection molding. Rheological, morphological and mechanical properties of PP and PP composites with and without NR or EPDM were studied. Adding NR or EPDM to PP composites, a significant increase in the impact strength and elongation at break is observed in the PP composite with rubber content more than 20% by weight. However, the tensile strength and Young’s modulus of the PP composites decrease with increasing rubber contents. Nevertheless, the tensile strength and Young’s modulus of the composites with rubber contents up to 10% are still higher than those of PP. Moreover, comparisons between NR and EPDM rubber on the mechanical properties of the PP composites were elucidated. The PP composites with EPDM rubber show slightly higher tensile strength and impact strength than the PP composites with NR.     

Ionomer Toughened Polyolefine

The morphology and properties of HDPE blends with Zn-SEPDM and GR were studied through SEM and mechanical property test. The results show that as Zn-SEPDM/GR content amounts to 20%, the blend becomes an IPN in structure, and that a rather high impact and tensile strength of HDPE may be obtained after blending. The antistatic effect, the softening point,and HDT of the blend are higher as compared to HDPE/Zn-SEPDM/ZnSt (zinc stearate).The effect of Zn-SEPDM on the compatibility the morphology and properties of IPP blends were studied by DSC, TEM and mechanical properties test. The results show that as Zn-SEPDM content exceeds 20%. Zn-SEPDM in the blend becomes continuous and an abrupt change in impact strength is incurred there from. Owing to the incorporation of ionic groups into EPDM.the strong interactions betWeen the chains make both the impact and the tensile strength of IPP remarkably higher     

Dimensional stability and mechanical behaviour of wood–plastic composites based on recycled and virgin high-density polyethylene (HDPE)

This paper investigated the stability, mechanical properties, and the microstructure of wood–plastic composites, which were made using either recycled or virgin high-density polyethylene (HDPE) with wood flour (Pinus radiata) as filler. The post-consumer HDPE was collected from plastics recycling plant and sawdust was obtained from a local sawmill. Composite panels were made from recycled HDPE through hot-press moulding exhibited excellent dimensional stability as compared to that made from virgin HDPE. The tensile and flexural properties of the composites based on recycled HDPE were equivalent to those based on virgin HDPE. Adding maleated polypropylene (MAPP) by 3–5 wt% in the composite formulation significantly improved both the stability and mechanical properties. Microstructure analysis of the fractured surfaces of MAPP modified composites confirmed improved interfacial bonding. Dimensional stability and strength properties of the composites can be improved by increasing the polymer content or by addition of coupling agent. This project has shown that the composites treated with coupling agents will be desirable as building materials due to their improved stability and strength properties.     

Effect of material and processing parameters on mechanical properties of Polypropylene/Ethylene–Propylene–Diene–Monomer/clay nanocomposites

Polypropylene/Ethylene–Propylene–Diene–Monomer (PP/EPDM) blends are well known for having a combination of favourable mechanical properties. In this paper, addition of organoclay to PP/EPDM to make PP/EPDM nanocomposites with enhanced mechanical properties is studied. PP/EPDM/organoclay nanocomposites were prepared using a lab scale twin-screw extruder. Maleic anhydride grafted polypropylene (PP-g-MA) was used to enhance the intercalation/exfoliation process and to create good adhesion at the polymer/polymer and polymer/filler interfaces. Taguchi method was employed to deign the experiments and optimize material and processing parameters for optimized mechanical properties. Organoclay (NC) and compatibilizer content were selected as material parameters and the main processing variables were feeding rate and average shear rate (RPM). X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to study the microstructure of the nanocomposites samples. It was observed that NC content and shear rate in extruder improved the tensile strength and modulus. Another important result was the insignificant effect of NC content on impact strength while increasing shear rate first increased and then decreased the impact strength.     

EPDM磺酸镁盐对HDPE填充体系力学性能影响的研究

合成了三元乙丙橡胶磺酸镁盐（Ｍｇ－ＳＥＰＤＭ）离聚体，测定了该离聚体的磺化度，研究了ＨＤＰＥ／Ｍｇ－ＳＥＰＤＭ／金属氢氧化物三元体系的力学性能，通过ＳＥＭ和多功能内耗仪对该体系的形态结构和动态力学性能进行了探讨。结果表明，Ｍｇ－ＳＥＰＤＭ中的离子基团通过物理交联可以增加ＨＤＰＥ的韧性，增强ＨＤＰＥ与金属氢氧化物的界面强度，提高体系的综合力学性能。