PET与HDPE的共混物研究

对聚对苯二甲酸乙二醇酯(PET)与高密度聚乙烯(HDPE)共混物近十几年来的研究进展进行了综述.PET与HDPE为不相容共混物,加入增容剂后,不仅增加了体系的相容性,而且改善了体系的性能.本文介绍了PET/HDPE共混体系的增容剂和性能.     

电子束辐照HDPE及其与绢英粉共混体系流变行为的研究

采用高压毛细管流变仪及HDAKE转矩流变仪对辐照HDPE（e-HDPE）及其与绢英粉（STC）共混体系的流变行为进行了研究。结果表明：由于电子束辐照引起HDPE发生氧化降解，因此表观粘度和混炼转矩降低；与HDPE／STC共混体系相比，e-HDPE/STC体系的表观粘度和混炼矩也降低，加工性能得到改善。     

γ-辐照对HDPE/PUR-T共混体系性能的影响

以高密度聚乙烯(HDPE)和热塑性聚氨酯弹性体(PUR-T)为主要原料,以马来酸酐接枝(乙烯/乙酸乙烯酯)共聚物(E/VAC-g-MAH)为增容剂,采用双螺杆挤出熔融共混技术制备了HDPE/PUR-T和HDPE/PUR-T/(E/VAC-g-MAH)等共混材料,利用60Co-γ射线源在较低辐照剂量(小于等于25 kGy)下对共混材料进行了γ-辐照。考察了γ-辐照、增容剂E/VAC-g-MAH对共混体系的力学性能、界面形态与熔体流动性能的影响。结果表明,同时采用γ-辐照与使用增容剂E/VAC-g-MAH两种增容方法,可以有效地改善HDPE/PUR-T的力学性能和相容性。     

γ射线辐照对HDPE/PA6共混体系的影响

采用FTIR、Molau实验，SEM，力学性能及阻隔性能测试方法，研究了γ射线辐照对高密度聚乙烯（HDPE）／尼龙6（PA6）共混体系的影响，结果表明，采用γ射线对HDPE进行辐照，在其分子链上引入了含氧极性基团，增加了HDPE分子的极性，改善了HDPE／PA6共混体系的相容性，提高了该共混体系的力学性能和对二甲苯的阻隔性能。     

聚烯烃改性PET的研究

通过PET与PP、HDPE、EPDM挤出共混，注射模塑制得试样。经DTA、SEM和力学性能测试，表征了共混体系的热行为、结构形态和力学性能。结果表明，在PET/PP(EPDM、HDPE)共混体系中，加入少量的PP-g-MI(EPDM-g-MAH、PE-g-MI)，可较好地改善PEt与PP(EPDM、HDPE)之间的相容性，使分散相在PET基体连续相中分散均匀，分散相尺寸减小，增加了两相间界面的粘结力；同时对PET的结晶有较强的促进作用，使其冷结晶温度降低，改善了PET的加工性能；并且能大幅度提高共混物的冲击强度。     

HDPE熔融接枝GMA/St及其增容HDPE/PET合金性能的研究

利用HAAKE流变仪,采用熔融接枝法分别制备了甲基丙烯酸缩水甘油酯(GMA)、GMA/苯乙烯(St)接枝高密度聚乙烯(HDPE),将所得接枝物HDPE-g-GMA和HDPE-g-(GMA-co-St)作为HDPE/PET共混合金的反应性增容剂,研究了其对体系力学性能和热致形状记忆性能等的影响。结果表明:采用GMA/St双组分单体具有较高的接枝率,生成的接枝物对HDPE/聚对苯二甲酸乙二醇酯(PET)共混合金的增容效果较好;提高了体系的力学性能和热致形状记忆性能,且HDPE-g-(GMA-co-St)含量为5～10phr时,合金具有较好的综合性能。     

HDPE/mLLDPE混炼后的性能与结构

高密度聚乙烯/茂金属线性低密度聚乙烯(HDPE/mLLDPE)40/60共混物经混炼器混炼后的冲击强度比未经混炼器混炼的HDPE增加了96．2%,比未经混炼器混炼的mLLDPE增加了27．0%,其拉伸强度比未经混炼器的mLLDPE增加了49．1%。这表明在混炼器的强剪切分散作用下,HDPE,mLLDPE共混对HDPE和mLLDPE有显著的增韧作用。其微观结构测试表明,mLLDPE与HDPE形成了共晶结构,HDPE含量高的HDPE/mLLDPE共混体系试样内部的晶粒尺寸更为均一。     

充油SEBS/HDPE/CaCO_3复合材料加工性能及力学性能的研究

采用转矩流变仪共混方法研究充油SEBS/HDPE/CaCO_3复合材料不同CaCO_3组分量、充油比、不同HDPE用量对复合材料加工性能、拉伸性能、硬度的影响。结果表明:随着CaCO_3的增加复合材料的加工性能变差、邵氏A硬度增加、拉伸强度降低、断裂伸长率降低。随着HDPE的增加复合材料的加工性能变好、邵氏A硬度增加、拉伸强度增加、断裂伸长率减小。随着充油比的增加共混物体系的加工性能变好、拉伸强度减少、断裂伸长率增加。     

PP/HDPE/滑石粉复合材料微孔发泡实验研究

为了改善聚丙烯(PP)的微孔发泡性能,将PP与高密度聚乙烯(HDPE)共混,提高其熔体强度;然后在PP/HDPE共混体系中加入少量滑石粉,研究滑石粉的用量对共混体系熔体强度及微孔发泡过程的影响。研究结果表明,滑石粉的加入使体系的熔体强度提高,发泡样品的泡孔结构变得更均匀。而且,随着滑石粉用量的增加,泡孔尺寸减小,泡孔密度增加。     

反应挤出HDPE/PET共混合金结构与性能研究

采用DSC、WAXD、SEM及TGA等方法研究了HDPE/PET共混合金在增容剂E/VAC或E/AA作用下的结晶性、形态结构及热稳定性。结果表明,E/VAC或E/AA的加入,使HDPE/PET体系中HDPE组分的熔融热焓降低,结晶度下降,但熔融峰位置和晶胞结构基本保持不变;从SEM照片可以观察到E/VAC、E/AA对共混体系具有一定的增容作用,E/AA的效果优于E/VAC;共混体系的热稳定性随E/VAC、E/AA的加入有所下降,E/AA的下降幅度则远远小于E/VAC。     

Dynamic Mechanical Properties of Compatibilized PET with Radiation Oxidized HDPE

Summary Binary blends of HDPE/PET exhibit poor mechanical properties because of their non compatibility. In this work, HDPE was oxidized by gamma-ray preirradiation in air, subsequently heated to destroy peroxides formed by this irradiation and to form polar groups in the HDPE, and then extruded with PET as a compatibilizing method of the blend. The dynamic mechanical properties were studied, and an improvement was observed when the PET content was increased while the HDPE used was irradiated. The largest increase in the mechanical properties was observed for PET contents between 10 and 20% (w/w). The improvement in the dynamic mechanical properties is believed to occur because of a percolation effect of the PET in the HDPE matrix and the radiation-improved compatibility by means of polar groups formed in the polyethylene.     

原位增容HDPE／PET共混体系反应挤出形态结构的研究

通过扫描电镜照片（ＳＥＭ）研究了ＨＤＰＥ／ＰＥＴ共混体系在双螺杆反应挤出过程中,共混合金冲击断面的形态特征。结果表明,增容剂ＥＶＡ或ＥＡＡ均对ＨＤＰＥ／ＰＥＴ共混体系具有一定的增容作用;使分散相颗粒减小,且变得较为均匀,两相界面变得模糊,界面粘结力增强。其中,ＥＡＡ的增容效果优于ＥＶＡ。在此增容的基础上,选用有机化合物Ｄ作为催化剂,在熔融加工的过程中,使ＰＥＴ与ＥＶＡ或ＥＡＡ发生酯交换或酸－酯交换反应,生成ＰＥＴ－ＥＶＡ或ＰＥＴ－ＥＡＡ接枝共聚物,达到了原位增容ＨＤＰＥ／ＰＥＴ共混体系的目的,从而进一步改善了体系的相容性,共混体系的力学性能也得到了有效的提高     

Improved compatibility of high‐density polyethylene/poly(ethylene terephthalate) blend by the use of blocked isocyanate group

The blocked isocyanate group (BHI) was synthesized to improve the storage stability of HI (2‐hydroxyethyl methacrylate combined with isophorone diisocyanate) and characterized by Fourier transform infrared spectroscopy (FTIR). High‐density polyethylene grafted with the blocked isocyanate group (HDPE‐g‐BHI) was used as a reactive compatibilizer for an immiscible high‐density polyethylene/poly(ethylene terephthalate) (HDPE/PET) blend. A possible reactive compatibilization mechanism is that regenerated isocyanate groups of HDPE functionalized by BHI react with the hydroxyl and carboxyl groups of PET during melt blending. The HDPE‐g‐BHI/PET blend showed the smaller size of a dispersed phase compared to the HDPE/PET blend, indicating improved compatibility between HDPE and PET. This increased compatibility was due to the formation of an in situ graft copolymer, which was confirmed by dynamic mechanical analysis. Differential scanning calorimetry (DSC) analysis represented that there were few changes in the crystallinity for the continuous PET phase of the HDPE‐g‐BHI/PET blends, compared with those of the HDPE/PET blends at the same composition. Tensile strengths and elongations at the break of the HDPE‐g‐BHI/PET blends were greater than those of the HDPE/PET blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1017–1024, 2000     

Study of masterbatch effect on miscibility and morphology in PET/HDPE blends

The present work studies the morphology in poly(ethylene-terephthalate)/polyethylene (PET/HDPE) polymer blends and its impact on blend properties. Mixing process in blend preparation is the important parameter for the type of obtained blend morphology and final blend properties, so two different mixing processes were used. In the first one, all components are mixed together while another one includes two step mixing procedure using two different types of masterbatch as compatibilizers for PET/HDPE system. Such blends can be considered in terms of PET polymer recycling in the presence of HDPE impurities in order to find suitable compatibilizers, which will enhance the interactions between these two polymers and represents the possible solution in recycling of heterogeneous polymer waste. The morphology of the studied PET/HDPE blends was inspected by scanning electron microscopy to examine the influence of the mixing process and various compositions on blends morphology, and interactions between PET and HDPE. The surface properties were characterized by contact angle measurements. The effect of the extrusion on the samples thermal behaviour was followed by DSC measurements. FTIR spectroscopy was used for the determination of interactions between blend constituents. It can be concluded that the type of mixing process and the carefully chosen compatibilizer are the important factors for obtaining the improved compatibility in PET/HDPE blends.     

Rheological behavior comparison between PET/HDPE and PC/HDPE microfibrillar blends

The rheological behaviors of in situ microfibrillar blends, including a typical semicrystalline/semicrystalline (polyethylene terephthalate (PET)/high‐density polyethylene (HDPE)) and a typical amorphous/semicrystalline (polycarbonate (PC)/HDPE) polymer blend were investigated in this study. PET and PC microfibrils exhibit different influences on the rheological behaviors of microfibrillar blends. The viscosity of the microfibrillar blends increases with increased PET and PC concentrations. Surprisingly, the length/diameter ratio of the microfibrils as a result of the hot stretch ratio (HSR) has an opposite influence on the rheological behavior of the two microfibrillar blends. The stretched PET/HDPE blend exhibits higher viscosity than the unstretched counterpart, while the stretched PC/HDPE blend exhibits lower viscosity than the unstretched blend. The data obtained in this study will be helpful for constructing a technical foundation for the recycling and utilization of PET, PC, and HDPE waste mixtures by manufacturing microfibrillar blends in the future. POLYM. ENG. SCI., 45:1231–1238, 2005. © 2005 Society of Plastics Engineers     

SEBS/HDPE共混物加工性能及力学性能的研究

以苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物（SEBS）／高密度聚乙烯（HDPE）为共混改性的研究对象，采用哈克转矩流变仪进行共混，讨论了不同用量、不同类型的HDPE对共混物加工流变性能、冲击性能和拉伸性能的影响。结果表明，当添加的HDPE份数达到20phr时，能显著提高共混物的冲击性能和拉伸性能，同时共混物的加工流变性能也有了很大的改善。因此质量比为100／20的SEBS／HDPE体系是一个比较理想的共混体系。     

Radiation effects on HDPE/EVA blends

In this article, we discuss the radiation effects of high‐density polyethylene (HDPE)/ethylene–vinyl acetate (EVA) copolymer blends. In comparison with the low‐density polyethylene/EVA blends, the EVA content in the HDPE/EVA blends had a lower enhancement effect on radiation crosslinking by γ‐ray irradiation in air. The phenomenon is discussed with the compatibility, morphology, and thermal properties of HDPE/EVA blends. The HDPE/EVA blends were partly compatible in the amorphous region, and radiation crosslinking of the HDPE/EVA blend was less significant, although increasing the amorphous region's content of the HDPE/EVA blends and the vinyl acetate content of EVA were beneficial to radiation crosslinking. The good compatibility was a prerequisite for the enhancement effect of EVA on the radiation crosslinking of the polyethylene/EVA copolymer. The radiation crosslinking and the degradation mechanism of HDPE/EVA blends were examined quantitatively by a novel method, the step analysis process of irradiated HDPE/EVA blends with a thermal gravimetric analysis technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 553–558, 2002     

Development of isotropic compatible HDPE/PP blends for structural applications

In an attempt to provide superior products for the structural applications, this study aimed at preparing isotropic compatible high density polyethylene (HDPE)/ polypropylene (PP) blends without the use of the expensive compatibilization technique. Morphological and structural characterizations of the homopolymers and blends were carried out. In addition, some of the structurally important mechanical and thermal properties were characterized. Such characterizations were performed to investigate whether or not the blends are compatible and therefore acceptable for the structural applications. Scanning electron microscope (SEM) micrographs of the blend samples indicate that the interfacial adhesion between HDPE and PP phases is intimate in the 5/95 HDPE‐PP, good in the 85/15 HDPE‐PP and 95/5 HDPE‐PP, fair in the 30/70 HDPE‐PP and very poor in the 50/50 HDPE‐PP. Similarly, mechanical and thermal responses of the first three blends are remarkable. The 30/70 HDPE‐PP blend displays a fairly good performance. Whereas, the properties of the 50/50 HDPE‐PP blend are very poor. This decides that the first three blends are compatible and, therefore, structurally attractive materials. The fourth is partially compatible and, as a consequence, can be rather acceptable for the structural applications. However, the fifth is incompatible and, of course, is not acceptable for such applications. On the other hand, SEM micrographs and differential scanning calorimetry results indicate that the crystalline structures of individual polymers are appreciably affected by blending. Additionally, the study reveals that the end use performance of blends is strongly dependent on the crystalline structure changes occurring in each component due to blending as well as the compatibility between the blend components. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

UHMWPE/HDPE共混物的流动性及力学性能的研究

采用不同MFR的HDPE与UHMWPE进行熔体共混。结果表明UHMWPE／HDPE共混物流动性和力学性能的变化受体系组成、熔体粘度比等因素的影响较大。HDPE的MFR过高、过低或用量过多，均不利于共混物流动性及综合力学性能的改善。当HDPE作为分散相时，易于实现向UHMWPE高粘弹粒子的渗透、分散及结合，共混物的．MFR及拉伸屈服强度、断裂强度、断裂伸长率均比UHMWPE有提高，共混物表现出协同效应；当UHMWPE为分散相或二者熔体粘度比差异过大时，混合效果变差，共混物综合力学性能下降；在某些中间配比下，二者表现出增链缠结效应，共混物MFR明显降低。     

POM共混增韧改性研究

研究了POM COPA、POM LDPE和POM HDPE三种共混体系,测试了不同配比共混物的冲击强度,对POM COPA及紫外线辐射的HDPE进行了红外光谱(FT IR)分析。结果表明:(1)在三种共混体系中,COPA对POM的增韧效果最佳,且COPA与POM分子间有氢键作用;(2)EVA在POM LDPE及POM HDPE共混体系中起相容剂的作用;(3)HDPE经紫外线辐射后,由于在其分子链上引入了极性羰基,从而大大提高了对POM的增韧效果。