Reactive compatibilizer precursors for LDPE/PA6 blends. II: maleic anhydride grafted polyethylenes

Several home made and commercially available polyethylene (PE) samples grafted with maleic anhydride (MA) (PE-g-MA) were used as compatibilizer precursors (CPs) for the reactive blending of low density PE (LDPE) with polyamide-6 (PA). Scope of the work was to compare the effectiveness of these CPs with that of a number of ethylene-acrylic acid copolymers (EAA), which had been employed in a previous study for the reactive compatibilization of the same blends, and to get a deeper insight into the coupling reactions producing the PA-g-CP copolymers that are thought to act as the true compatibilizers in these systems. To this end, binary CP/LDPE and CP/PA and ternary LDPE/PA/CP blends were prepared with a Brabender mixer and were characterized by DSC, SEM and solvent fractionation. The results show that the PE-g-MA copolymers react more rapidly with PA than the EAA copolymers and that their CP effectiveness depends critically on the microstructure and the molar mass of their PE backbones. In particular, the CPs produced by functionalization of LDPE were shown to be miscible with this blend component and to be scarcely available at the interface where reaction with PA is expected to occur. Conversely, the CPs prepared from the HDPE grades were immiscible with LDPE and showed better CP performance. Whereas the effectiveness of the EAA copolymers studied earlier had been shown to increase with an increase in the concentration of the carboxyl groups, the concentration of the succinic anhydride groups of the PE-g-MA CPs studied in this work was found to play a minor role, at least in the investigated range (0.3-3.0 wt% MA).     

ABS-g-MAH在PA 6/ABS合金中的应用

采用固相接枝的方法制备了马来酸酐(MAH)接枝丙烯腈-丁二烯-苯乙烯三元共聚物(ABS)(ABS-g-MAH),并以ABS-g-MAH为相容剂,制备了聚酰胺6(PA 6)/ABS合金.ABS-g-MAH能有效改善合金的相容性,提高合金的力学性能,当w(ABS-g-MAH)为10%时.合金的冲击强度与未添加相容剂的合金相比提高了30%左右,其拉伸强度、弯曲强度也显著提高.PA 6中加人ABS和ABS-g-MAH影响了其结晶形态,球晶显著减少,并出现了大量的片晶.PA 6的α松弛温度为70℃左右,而加入ABS和ABS-g-MAH后α松弛温度为115℃左右,并且出现明显的β松弛,γ松弛温度也从-50℃降到-70℃左右.     

The effect of zinc oxide addition on the compatibilization efficiency of maleic anhydride grafted high‐density polyethylene compatibilizer for high‐density polyethylene/polyamide 6 blends

A high‐density polyethylene with grafted maleic anhydride units has been investigated as a compatibilizer for high‐density polyethylene with polyamide 6. The material acts as an effective compatibilizer, causing a marked reduction in dispersed phase size as well as an increase in tensile strength and toughness. Compatibilizer also affects the glass‐transition temperature, crystallization kinetics, and amount of crystalline material for certain blend compositions. The addition of zinc cations, which are effective in increasing ethylene‐acid copolymer compatibilizer performance in low‐density polyethylene/polyamide blends, has little, if any, effect on compatibilizer performance in these high‐density polyethylene/polyamide blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3871–3881, 2007     

Non-isothermal crystallization kinetic and compatibility of PTT/PP blends by using maleic anhydride grafted polypropylene as compatibilizer

The crystallization behaviors, non-isothermal crystallization kinetics, and the morphology of poly(trimethylene terephthalate)/Polypropylene (PTT/PP) blends using a maleic anhydride grafted polypropylene (PP-g-MAH) as a compatibilizer were investigated by differential scanning calorimeter (DSC) and scanning electron microscope (SEM), respectively. The results suggested that the blends exhibited different crystallization and melting behaviors due to different content of PP-g-MAH. All of the DSC curves of the blends exhibited two exothermic peaks and endothermic peaks. The commonly used Avrami equation modified by Jeziorny, Ozawa theory and the method developed by Mo were used, respectively, to fit the primary stage of non-isothermal crystallization process. The results suggested that the crystallization rate of PTT component was increased, whereas, that of PP component was retarded with the introduction of PP-g-MAH. The effective activation energy was calculated by differential iso-conversional method developed by Vyazovkin. The SEM result suggested that the introduction of PP-g-MAH greatly improved the compatibility between PTT and PP, and decreased the size of dispersed particles.     

马来酸酐接枝SEBS对尼龙6/液晶共聚酯共混物的增容作用

通过流变行为和ＤＳＣ研究,发现马来酸酐接枝ＳＥＢＳ能有效地增容尼龙６／液晶共聚酯共混物。     

马来酸酐接枝聚乙烯/石墨导电纳米复合材料的研究

用溶液插层法制备了马来酸酐接枝聚乙烯(MGPE)/膨胀石墨(EG)导电纳米复合材料,以熔体混合法作对照,通过电导率测试和X射线衍射、透射电镜、扫描电镜和光学显微分析,研究了复合材料的制备方法-形态结构-导电性能关系和导电通路形成机理。溶液插层法复合材料的逾渗阈值(1.65%体积)仅约为熔体混合法复合材料(3.03%体积)的一半。上述复合材料的导电行为和差异可用统计逾渗理论结合材料的形态结构特征来说明。     

低分子量聚乙烯熔融接枝马来酸酐的研究

研究了吉林石化高密度聚乙烯装置副产低分子量聚乙烯与马来酸酐(MAH)的融熔接枝反应,考察了单体、引发剂用量、反应时间、温度对接枝率的影响。马来酸酐接枝低分子量聚乙烯应用于PE/CaCO3体系的性能测试结果表明,接枝物可以起到偶联剂的作用,改善体系的性能。     

苯乙烯/马来酸酐接枝聚乙烯蜡的研究

用溶液法制备了马来酸酐和马来酸酐/苯乙烯双单体接枝的聚乙烯蜡,考察了反应时间、温度、引发荆、单体用量对产物接枝率的影响.结果表明二叔丁基过氧化物是一种优良的接枝反应引发剂,在ω(引发剂)=0.4%、ω(马来酸酐)=6.0%、ω(苯乙烯)=4.0%、反应温度143℃、反应时间2.5 h的条件下,聚乙烯蜡接枝率为3.4%.并对产品进行了红外光谱分析、热分析表征.     

热熔胶用马来酸酐接枝聚乙烯研究进展

通过双螺杆挤出机将马来酸酐熔融接枝聚乙烯,制备的聚乙烯热熔胶具有粘接性能强、价格低等优点,广泛地应用于钢塑复合管。本文根据近年来聚乙烯热熔胶的研究方向,综述了新型引发剂及引发方式对接枝反应的影响;比较了不同种类聚乙烯接枝效果的差异;总结了改性单体对热熔胶性能的改善以及温度、挤出机螺杆结构和转速等工艺条件对聚乙烯热熔胶的影响。分别总结了化学滴定法和红外光谱法对接枝率的表征;简述了材料表面处理和涂胶工艺对剥离强度的影响。分析了热熔胶剥离强度传统制样方法的不足,并总结了能得到稳定真实剥离强度的制样方案。展望了低马来酸酐含量、高粘接强度的绿色环保型聚乙烯热熔胶的研究前景。     

Comparative study of different maleic anhydride grafted compatibilizer precursors towards LDPE/PA6 blends: Morphology and mechanical properties

The study deals with the effectiveness of maleic anhydride grafted styrene-b-ethylene-co-propylene copolymer (SEPMA) as compatibilizer precursor (CP) for blends of low density polyethylene (LDPE) with polyamide-6 (PA). The CP was produced by grafting MA onto SEP in the melt. The specific interactions between the CP and the blends components have been investigated through characterizations of the binary LDPE/CP and PA/CP blends. The compatibilizing efficiency of the MA-grafted SEP, as revealed by the thermal properties and the morphology of the compatibilized blends, has been shown to be excellent. The morphology, as well as the mechanical properties of the compatibilized with SEPMA 75/25 w/w and 25/75 w/w LDPE/PA6 blends have been compared with those of the blends compatibilized with maleic anhydride functionalized HDPE sample (1-HDPE-g-MA) and with a commercial maleic anhydride grafted styrene-b-(ethylene-co-1-butene)-b-styrene copolymer (SEBSMA1). The results show that the strong compatibilizing efficiency of SEPMA is comparable with that of SEBSMA1, while 1-HDPE-g-MA exhibits a slightly lower activity, particularly for the blends, in which PA is the matrix phase.     

Effect of maleic anhydride grafted polybutadiene on the compatibility of polyamide 66/acrylonitrile‐butadiene‐styrene copolymer blend

The addition of maleic anhydride grafted polybutadiene (PB‐g‐MAH) can greatly improve the compatibility of polyamide 66 (PA66)/acrylonitrile‐butadiene‐styrene copolymer (ABS) blends. Unlike the commonly used compatibilizers in polyamide/ABS blends, PB‐g‐MAH is compatible with the ABS particles' core phase polybutadiene (PB), rather than the shell styrene‐acrylonitrile (SAN). The compatibility and interaction of the components in the blends were characterized by Fourier transform‐infrared spectra (FTIR), Molau tests, melt flow index (MFI), dynamic mechanical analyses (DMA), and scanning electron microscopic (SEM) observations. The results show that PB‐g‐MAH can react with the amino end groups in PA66 while entangle with the PB phase in ABS. In this way, the compatibilizer anchors at the interface of PA66/ABS blend. The morphology study of the fracture sections before and after tensile test reveals that the ABS particles were dispersed uniformly in the PA66 matrix and the interfacial adhesion between PA66 and ABS was increased significantly. The mechanical properties of the blends thus were enhanced with the improving of the compatibility. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Evaluation of polypropylene grafted with maleic anhydride and styrene as a compatibilizer for polypropylene/clay nanocomposites

Among modified Poly(propylene)s (PPs) grafted with polar monomers, PP grafted with maleic anhydride (PP-g-MAH) is known to be the most efficient compatibilizer for PP/clay nanocomposites, since it provides well-dispersed nanostructures and yields optimal physical properties of the nanocomposites. One drawback of this material, however, is that it becomes brittle and its viscosity decreases drastically, leading to nanocomposites with low toughness as the graft degree of MAH increases. Therefore, there is a limitation to increasing both stiffness and toughness of PP/clay nanocomposites with PP-g-MAH. In this study, we investigated the performance of a PP grafted with maleic anhydride and styrene (PP-g-MAH-St) as compatibilizers in PP/clay nanocomposites. It was found that the incorporation of styrene as a comonomer prevents molecular weight reduction of the PP main chain upon high loading of a radical initiator for high graft degree of MAH. The compatibilizers (PP-g-MAH-St) thus obtained show good compatibilizing performance in PP/clay nanocomposites. The PP/clay nanocomposites compatibilized by PP-g-MAH-St show both high stiffness and toughness, which is accomplished by using a compatibilizer of higher viscosity compared with PP-g-MAH.     

马来酸酐改性氯化聚丙烯和醇酸树脂相容性的研究

研究了由70％的二甲苯、不同配比的醇酸树脂和马来酸酐改性氯化聚丙烯构成的三元体系复配互容情况。用红外表征了马来酸酐改性氯化聚丙烯与344#树脂的质量比为1／2时复配液的相容性；用光泽值表征溶剂挥发后。马来酸酐改性氯化聚丙烯与醇酸类树脂的质量比分别为2／1、l／l、1／2、1／10、0／10时二元共混涂膜的透明性。结果表明：随着改性氯化聚丙烯接枝率的提高。氯化聚丙烯和醇酸树脂的相容性明显增强。     

Synthesis of polypropylene‐graft‐maleic anhydride compatibilizer and evaluation of nylon 6/polypropylene blend properties

Polymer blends based on polyolefins are of a great interest owing to their broad spectrum of properties and practical applications. However, because of poor compatibilities of components, most of these systems generally exhibit high interfacial tension, a low degree of dispersion and poor mechanical properties. It is generally accepted that polypropylene (PP) and nylon 6 (N6) are not compatible and that their blending results in poor materials. The compatibility can be improved by the addition of a compatibilizer, and in this study PP was functionalized by maleic anhydride (MAH) in the presence of an optimized amount of dicumyl peroxide (DCP). The reaction was carried out in the molten state using an internal mixer. Then, once the compatibilizer polypropylene‐graft‐maleic anhydride (PP‐g‐MAH) was prepared, it was added at various concentrations (2.5–10 wt%) to 30/70 glass fibre reinforced N6 (GFRN6) PP, and the mechanical properties were evaluated. It was found that the incorporation of the compatibilizer enhanced the tensile properties (tensile strength and modulus) as well as the Izod impact properties of the notched samples. This was attributed to better interfacial adhesion as evidenced by scanning electron microscopy (SEM). The optimum in these properties was achieved at a critical PP‐g‐MAH concentration. Copyright © 2005 Society of Chemical Industry     

Polyethylene grafted maleic anhydride to improve wettability of liquid on polyethylene films

Blends of linear low density polyethylene (LLDPE) and LLDPE grafted maleic anhydride (LLDPE‐g‐MA) were prepared by melt mixing. The surface of cast films with different contents and types of maleated PE were characterized through contact angle and wetting tension measurements, as well as attenuated total reflection IR spectroscopy. The tensile properties and light transmission of extruded films, as well as the performance of these films compared with commercial “antifog” films, for greenhouses were determined. The carbonyl polar groups on the surface of LLDPE/LLDPE‐g‐MA blends increased, and the equilibrium contact angles of water and dimethylformamide decreased when the content of maleated PE increased. Films made with these blends showed a noticeable reduction in water drop formation as the MA content was increased and when using LLDPE‐g‐MA of lower molecular weight. The light transmission through these films under condensation was improved when using increased contents of MA, which promotes better wetting of the water on the surface. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1802–1808, 2001     

Effect of maleic anhydride grafted polypropylene compatibilizer on the morphology and properties of polypropylene/multiwalled carbon nanotube composite

The effect of maleic anhydride grafted polypropylene (MA‐g‐PP) compatibilizer on the mechanical and electrical properties of a polypropylene‐carbon nanotube composite is presented. Commercially available grades of polypropylene homopolymer (PP) and multiwalled CNT (MCNT) were used to prepare composites (PP/MCNT) by melt compounding. The effects of maleic anhydride graft level and loading on material properties were investigated. The addition of MCNT without compatibilizer enhanced the mechanical properties of PP, whereas addition of both grades of MA‐g‐PP alone had a detrimental effect. When MA‐g‐PP was added as a compatiblizer to the PP/MCNT composite, flexural and tensile moduli increased, indicating that enhanced levels of MCNT dispersion within PP had been achieved. Strength of the nanocomposite decreased with the addition of both grades of MA‐g‐PP, possibly due to the deterioration of the mechanical properties of the polymer in the presence of lower molecular weight MA‐g‐PP. Electrical resistivity improved with both grades of MA‐g‐PP, with higher maleic anhydride graft levels having the most significant effect. Scanning electron microscopy analysis confirmed that the optimum state of dispersion was for the nanocomposite prepared with MA‐g‐PP with highest grafting level. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Structural characterization of maleic anhydride grafted polyethylene by C NMR spectroscopy

Maleic anhydride grafted polyethylene, [2,3-¹³C₂] MA-g-PE, which was synthesized with ¹³C labeled maleic anhydride [2,3-¹³C₂] MA in solution, was characterized by ¹³C NMR spectroscopy in order to make clear the structure of graft groups. The results reveal that [2,3-¹³C₂] MA-g-PE has succinic anhydride oligomeric grafts with a terminal unsaturated MA ring in addition to well-known saturated succinic anhydride oligomeric grafts and that the former grafts are longer but fewer than the latter.     

弹性体接枝马来酸酐对PP/PA6 的增容作用

以4种弹性体接枝马来酸酐(MAH)共聚物作为聚丙烯/聚酰胺6(PP/PA6)共混体系的增容剂,从界面相互作用、形态结构和力学性能等方面比较了它们的增容作用。乙烯-辛烯共聚物接枝马来酸酐(POE-g-MAH)和乙丙三元共聚物接枝MAH(EPDM-g-MAH)使PP与PA6两相间的界面相互作用增强,增容效果较好;POE-g-MAH为增容剂时,PA6粒子分布较均匀,粒径约为1μm。POE-g-MAH能明显改善PP/PA6共混体系的韧性和强度,具有良好的增容作用。当w(POE-g-MAH)为10%时,w(PA6)为60%的共混体系拉伸强度最高,达到53.4MPa;适当增加PA6用量,可明显改善共混体系的流动性。     

A novel preparation method of maleic anhydride grafted syndiotactic polystyrene and its blend performance with nylon6

Summary This work is intended to provide a method for the preparation of maleic anhydride grafted syndiotactic polystyrene (sPS-g-MA). In particular, a novel solid reaction method by a radical grafting approach is investigated. The grafting reaction is performed at a solid state, where the syndiotactic polystyrene (sPS) is swollen in solvent at relatively low temperature compared to the conventional melt modification method. The formation of sPS-g-MA is directly confirmed by Fourier transform infrared spectroscopy and by the morphology observation of sPS/polyamide-6 (Nylon6) blends, when sPS-g-MA is used as a reactive compatibilizer. Received: 27 February 2002 / Revised version: 26 April 2002 / Accepted: 30 April 2002     

Improved compatibility between polyamide and polypropylene by the use of maleic anhydride grafted SEBS

Blends containing equal weight fractions of polypropylene (PP) and polyamide (PA-6 and PA-6.6) and up to 25% of a compatibilizing thermoplastic elastomer, either polystyrene-block-poly(ethylene-stat-butylene)-block-polystyrene (SEBS) or SEBS modified by maleic anhydride (SEBS-MA), were prepared by melt mixing. In all these blends, PP formed the continuous matrix phase. Even at high concentrations, unmodified SEBS was found to be a poor compatibilizer, affecting mainly the properties of the matrix. The graft copolymer formed, by reaction between SEBS-MA and polyamide during melt mixing, strongly influenced the blend morphology, by forming an interphase, separating the PA phase domains from the matrix. The crystallization behaviour of PP indicated that full coverage required between 3% and 5% SEBS-MA at the intense mixing conditions used. Above this level, the total surface area of the polyamide domains seemed to increase in direct proportion to the concentration of SEBS-MA. The thickness of the interphase layer was estimated to be about 15 nm. At high concentrations of SEBS-MA, the PA domains agglomerated and formed extended structures held together by the interphase polymer. This was reflected by the stress–strain and rheological behaviour of the blends. In blends with PA domains of small volume, crystallization of PA was delayed. The rate of water absorption was very low in blends containing SEBS-MA, much lower than in corresponding blends containing SEBS.