Rheological,thermal, and morphological properties of ABS–PA1010 blends

Noncompatibilized and compatibilized ABS–nylon1010 blends were prepared by melt mixing. Polystyrene and glycidyl methacrylate (SG) copolymer was used as a compatibilizer to enhance the interfacial adhesion and to control the morphology. This SG copolymer contains reactive glycidyl groups that are able to react with PA1010 end groups ( NH₂ or  COOH) under melt conditions to form SG‐g‐Nylon copolymer. Effects of the compatibilizer SG on the rheological, thermal, and morphological properties were investigated by capillary rheometer, DSC, and SEM techniques. The compatibilized ABS–PA1010 blend has higher viscosity, lower crystallinity, and smaller phase domain compared to the corresponding noncompatibilized blend. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 683–688, 1999     

High‐frequency welding of thermoplastic LLDPE/PA 6/PE‐g‐MAH ternary blends

High frequency (HF) welding of linear low density polyethylene (LLDPE) melt blends with polyamide 6 (PA6) was done at 27.12 MHz using maleic anhydride grafted polyethylene (PE‐g‐MAH) as compatibilizer. HF welding was not possible for the blends at room temperature, but possible at higher temperatures (50, 80°C) although the maximum relaxation frequency was lower than the operating frequency. Greater dielectric constant, dissipation factor, and welding performance were obtained when PA 6 was premixed with PE‐g‐MAH rather than the one‐shot process where all the components were mixed simultaneously. This was interpreted in terms of lowered viscosity of PA 6 phase, which encapsulates the flow effectively and provides great skin effect. Also, the peeling force of resin–resin was greater than resin–nylon mesh due to the higher melting temperature and vacancy of nylon mesh. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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.     

PA 6/EPDM-g-MAH/HDPE三元共混物的形态与力学性能

制备了聚酰胺(PA)6/马来酸酐(MAH)接枝三元乙丙橡胶(EPDM)(EPDM-g-MAH)/高密度聚乙烯(HDPE)三元共混物,采用扫描电子显微镜观察了三元共混物的相形态,研究了注塑过程的二次剪切流动对该三元共混物相形态的影响,以及三元共混物相形态对其力学性能的影响。结果表明:二次剪切流动有利于PA 6/EPDM-g-MAH/HDPE体系向热力学最稳定的壳核结构发生转变。与PA 6/EPDM-g-MAH二元共混物相比,该三元共混物的力学性能得到较大改善,w(EPDM-g-MAH)为15%时,其Izod缺口冲击强度达85.83 kJ/m2,是纯PA 6的9倍,是同等橡胶含量的PA 6/EPDM-g-MAH二元共混物的2倍。     

Relationship between structure and properties in high‐performance PA6/SEBS‐g‐MA/(PPO/PS) blends: The role of PPO and PS

This work aimed at studying the role of poly(phenylene oxide) (PPO) and polystyrene (PS) in toughening polyamide‐6 (PA6)/styrene‐ethylene‐butadiene‐styrene block copolymer grafted with maleic anhydride (SEBS‐g‐MA) blends. The effects of weight ratio and content of PPO/PS on the morphology and mechanical behaviors of PA6/SEBS‐g‐MA/(PPO/PS) blends were studied by scanning electron microscope and mechanical tests. Driving by the interfacial tension and the spreading coefficient, the “core–shell” particles formed by PPO/PS (core) and SEBS‐g‐MA (shell) played the key role in toughening the PA6 blends. As PS improved the distribution of the “core–shell” particles due to its low viscosity, and PPO guaranteed the entanglement density of the PPO/PS phase, the 3/1 weight ratio of PPO/PS supplied the blends optimal mechanical properties. Within certain range, the increased content of PPO/PS could supply more efficient toughening particles and bring better mechanical properties. Thus, by adjusting the weight ratio and content of PPO and PS, the PA6/SEBS‐g‐MA/(PPO/PS) blends with excellent impact strength, high tensile strength, and good heat deflection temperature were obtained. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45281.     

Fractionated crystallization of dispersed PA6 phase of PP/PP‐g‐MAH/PA6 blends

Fractionated crystallization behavior of dispersed PA6 phase in PP/PA6 blends compatibilized with PP‐g‐MAH was investigated by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), polarized light microscopy (PLM), and wide‐angle X‐ray diffraction (WAXD) in this work. The lack of usual active heterogeneities in the dispersed droplet was the key factor for the fractionated crystallization of PA6. The crystals formed with less efficient nuclei might contain more defects in the crystal structures than those crystallized with the usual active nuclei. The lower the crystallization temperature, the lesser the perfection of the crystals and the lower crystallinity would be. The fractionated crystallization of PP droplets encapsulated by PA6 domains was also observed. The effect of existing PP‐g‐MAH‐g‐PA6 copolymer located at the interface on the fractionated crystallization could not be detected in this work. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3742–3755, 2004     

Polymer blends of PA6 and PPE compatibilized by phenolic novolac epoxy coupler

A commercially available multi-functional epoxy monomer, phenolic novolac epoxy (PNE) resin, has demonstrated to be an effective reactive compatibilizer for the blends of polyamide-6 (PA6) and poly(2,6-dimethyl-1,4-phenylene ether) (PPE). It requires about 1/10 by weight relative to a typical conventional reactive compatibilizer to achieve same level of compatibilization in terms of mechanical property improvements. By acting as a coupler, this multi-functional epoxy can react with PA6 and PPE during melt blending and produces the desirable PA6-co-PNE-co-PPE mixed copolymers at the interface. This in situ-formed copolymer containing PA6 and PPE segments tends to reside at the interface between PA6 and PPE domains to reduce melt interfacial tension and enhance interface adhesion as an efficient compatibilizer of the PA6/PPE blends.     

Preparation and properties of compatibilized PVC/SMA‐g‐PA6 blends

The morphology and mechanical properties of PVC/SMA‐g‐PA6 blends were investigated in this paper. Graft to polymer SMA‐g‐PA6 was prepared via a solution graft reaction between SMA and PA6. FTIR test evidences the occurrence of the graft reaction between SMA and PA6. DSC analysis shows that SMA‐g‐PA6 has a lower melting point of 187°C, which may result in a decrease in crystallinity of PA6 and thus enable efficient blending of SMA‐g‐PA6 and PVC. Compatibilization was evidenced by the dramatic increase in mechanical properties, the smaller particle size and finer dispersion of PA6 in PVC matrix, and, further, a cocontinuous morphology at 16 wt % SMA‐g‐PA6 content. SMA‐g‐PA6 from the solution graft reaction can toughen and reinforce PVC material. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 432–439, 2004     

Effects of olefin‐based compatibilizers on the morphology,thermal and mechanical properties of ABS/polyamide‐6 blends

In this study, commercially available epoxidized and maleated olefinic copolymers, EMA‐GMA (ethylene‐methyl acrylate‐glycidyl methacrylate) and EnBACO‐MAH (ethylene‐n butyl acrylate‐carbon monoxide‐maleic anhydride), were used at 0, 5, and 10% by weight to compatibilize the blend composed of ABS (acrylonitrile‐butadiene‐styrene) terpolymer and PA6 (polyamide 6). Compatibilizing performance of these two olefinic polymers was investigated from blend morphologies, thermal and mechanical properties as a function of blend composition, and compatibilizer loading level. Scanning electron microscopy (SEM) studies showed that incorporation of compatibilizer resulted in a fine morphology with reduced dispersed particle diameter at the presence of 5% compatibilizer. The crystallization behavior of PA6 phase in the blends was explored for selected blend compositions by differential scanning calorimetry (DSC). At high compatibilizer level a decrease in the degree of crystallization was observed. In 10% compatibilizer containing blends, formation of γ‐crystals was observed contrary to other compatibilizer compositions. The behavior of the compatibilized blend system in tensile testing showed the negative effect of using excess compatibilizer. Different trends in yield strengths and strain at break values were observed depending on compatibilizer type, loading level, and blend composition. With 5% EnBACO‐MAH, the blend toughness was observed to be the highest at room temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 926–935, 2007     

Morphological and mechanical properties of PP/ABS blends compatibilized with PP‐g‐acrylic acid

Polypropylene (PP) and acrylonitrile–butadiene–styrene (ABS) blends were prepared by a melt extrusion process. PP‐g‐acrylic acid was used as a compatibilizer. Blends with various compositions of PP, compatibilizer, and ABS were prepared and studied for morphological and mechanical properties. PP‐rich ternary blends showed good morphological and mechanical properties. The use of 5 wt % PP‐g‐acrylic acid as a compatibilizer resulted in a fine and homogeneous dispersion of the ABS phase in the PP phase. The experimental data of the tensile modulus showed good agreement in PP‐rich compositions with that generated from Kerner's model with perfect adhesion. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1731–1741, 2001     

HDPE-g-GMA对PA6/UHMWPE共混物性能的影响

采用自制甲基丙烯酸缩水甘油酯接枝高密度聚乙烯(HDPE-g-GMA)作为增容剂来增容尼龙6/超高分子量聚乙烯(PA6/UHMWPE)共混物。通过Molau试验、红外光谱分析、扫描电子显微镜观察和物理力学性能测试,研究了HDPE-g-GMA在熔融共混过程中对PA6/UHMWPE共混物的增容作用。结果表明,HDPE-g-GMA与PA6发生化学反应所生成的接枝聚合物对PA6/UHMWPE共混物有较好的增容作用;PA6/UHMWPE共混物的界面形态和力学性能均有较大改善．吸水率也有所降低。     

Effect of EPDM‐g‐MAH on the morphology and properties of PA6/EPDM/HDPE ternary blends

The formation of core‐shell morphology within the dispersed phase was studied for composite droplet polymer‐blend systems comprising a polyamide‐6 matrix, ethylene‐propylene‐diene terpolymer (EPDM) shell and high density polyethylene (HDPE) core. In this article, the effect of EPDM with different molecular weights on the morphology and properties of the blends were studied. To improve the compatibility of the ternary blends, EPDM was modified by grafting with maleic anhydride (EPDM‐g‐MAH). It was found that core‐shell morphology with EPDM‐g‐MAH as shell and HDPE as core and separated dispersion morphology of EPDM‐g‐MAH and HDPE phase were obtained separately in PA6 matrix with different molecular weights of EPDM‐g‐MAH in the blends. DSC measurement indicated that there may be some co‐crystals in the blends due to the formation of core‐shell structure. Mechanical tests showed that PA6/EPDM‐g‐MAH/HDPE ternary blends with the core‐shell morphology exhibited a remarkable rise in the elongation at break. With more perfect core‐shell composite droplets and co‐crystals, the impact strength of the ternary blends could be greatly increased to 51.38 kJ m^?2, almost 10 times higher than that of pure PA6 (5.50 kJ m^?2). POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Morphology,thermal behavior,and mechanical properties of PA1010/PP and PA 1010/PP-g-GMA blends

The modification of polypropylene (PP) was accomplished by melt grafting glycidyl methacrylate (GMA) on its molecular chains. The resulting PP-g-GMA was used to prepare binary blends of polyamide 1010 (PA1010) and PP-g-GMA. Different blend morphologies were observed by scanning electron microscopy (SEM) according to the nature and content of PA1010 used. Comparing the PA1010/PP-g-GMA and PA1010/PP binary blends, the size of the domains of PP-g-GMA were much smaller than that of PP at the same compositions. It was found that mechanical properties of PA1010/PP-g-GMA blends were obviously better than that of PA1010/PP blends, and the mechanical properties were significantly influenced by wetting conditions for uncompatibilized and compatibilized blends. A different dependence of the flexural modulus on water was found for PA1010/PP and PA1010/PP-g-GMA. These behaviors could be attributed to the chemical interactions between the two components and good dispersion in PA1010/PP-g-GMA blends. Thermal and rheological analyses were performed to confirm the possible chemical reactions taking place during the blending process. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1489–1498, 1997     

The Effect of Compatibilizer on Morphology and Mechanical Properties of PA6/UHMWPE Blends

Abstract

This work deal with the effect of compatibilizer on the morphological and mechanic properties of polyamide 6 and ultrahigh molecular weight polyethylene (PA6/UHMWPE) blends. The blends were prepared by means of a twin-screw extruder. The compatibilizer was produced by grafting maleic anhydride (MAH) onto high density polyethylene (HDPE). The resulting HDPE-g-MAH was used to prepare ternary blends of PA6/HDPE-g-MAH/UHMWPE by melt mixing. The size of domain of UHMWPE in PA6/HDPE-g-MAH/UHMWPE blends is much smaller than that in PA6/UHMWPE blends. It was found that mechanical properties of PA6/HDPE-g-MAH/UHMWPE blends obviously surpassed that of PA6/UHMWPE blends. These behavior could be attributed to chemical reactions between MAH in HDPE-g-MAH and terminal amino groups of PA6. Thermal analysis were performed to confirm the possible chemical reactions taken place during the blending process.     

Morphology and properties of PBT/nylon 6/EVA‐g‐MAH ternary blends prepared by reactive extrusion

Morphology and properties of poly(butylene terephthalate) (PBT)/nylon 6 (PA6)/EVA‐g‐MAH ternary blends were investigated. The blends were prepared in a corotating, intermeshing, twin‐screw extruder. The incorporation of maleic anhyride (MAH) grafted onto ethylene‐vinyl acetate copolymer (EVA) (EVA‐g‐MAH) in the PBT/PA6 binary blends decreased the tensile and flexural strength but increased the impact strength, while the mechanical properties of the PBT/PA6 blends were decreased with increasing PA6 content regardless of the presence or absence of the EVA‐g‐MAH. The morphology studies of the ternary blends showed gross phase separation. The rheological properties of the ternary blends suggested that excessively high reactivity between amine end groups of PA6 and MAH grafted onto EVA makes the compatibility between PBT and PA6 worse, although EVA‐g‐MAH was expected to work as a compatibilizer for PBT/PA6 blends. The degree of reactivity between functional groups in PBT, PA6, and EVA‐g‐MAH was also examined by investigating the effect of blending sequence on the properties of the ternary blends.     

Morphology evolution of miscible blends between crystalline PA6 and amorphous PA6IcoT

The morphology evolution of miscible blends of a semicrystalline polyamide 6 (PA6) and an amorphous polyamide 6Ico6T (PA6IcoT) was investigated using an internal Brabender mixer at a temperature range 220–260°C. Morphology of the blends was characterized by scanning electron microscopy (SEM) and laser particle analysis. Temperature rising dissolution was used to separate the different phases of the blends and the phase compositions were determined by Fourier transform infrared (FTIR) spectroscopy. The particle size evolution of the dispersed phase (PA6) was calculated and agreed well with experimental observation. It was found that the particle size was quickly reduced to nanometer scale after several minutes of processing. A convection‐diffusion model was adopted to study the phase evolution during melt–melt mixing stage and compute the dimension of each phase. The results strongly support the notion of existence of distinct phases during blending, whose development can be well described by the model. The dispersed phase is reduced mainly by stretching of flow, while the broadening of the blending phase can be primarily attributed to molecular diffusion. The study also suggests the possibility to prepare novel polymer blends with nanometer sized domain of high uniformity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Studies on fracture behavior of tough PA6/PP blends

Fracture toughness of injection-molded PA6/PP blends compatibilized with SEBS-g-MA was studied using deeply double-edge notched tension (DDENT) specimens according to the essential work of fracture procedure. The fracture mechanical studies also included tensile impact tests on the DDENT specimens and characterization of the fracture surfaces by electron microscopy. The results were compared with those of traditional tensile tests and Izod impact tests on single-edge notched samples, and the sensibility of the methods was evaluated. Effects of sample position, ligament length, testing direction, and test speed were studied as well. It was found that the essential work of fracture concept, earlier applied to thin sheets, can also be applied to injection-molded tough blends. High deformation of the skin may, however, interfere with the measurements and cause a “tail” in the load-deformation curves. The plastic work of fracture (w_p) was found to correlate with the impact strength, and thus, it described the toughness. The highest values for work of fracture were recorded for the compatibilized blend with a PA6/PP ratio of 80/20. The essential work of fracture (w_e) in turn increased with increasing PA6 content and behaved like tensile strength. The test speed was found to affect the fracture behavior substantially: differences between the materials were more pronounced in high-speed tensile impact tests, which revealed signs of cavitation in addition to large-scale plastic deformation for the tough PA6-rich blend compositions. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2209–2220, 1997     

Crystallization behavior of PP/PP‐g‐MAH/GFR PA66 blends: Establishment of their continuous‐cooling‐transformation of relative crystallinity diagrams

Polypropylene/polypropylene‐grafted‐maleic anhydride/glass fiber reinforced polyamide 66 (PP/PP‐g‐MAH/GFR PA 66) blends‐composites with and without the addition of polypropylene‐grafted‐maleic anhydride (PP‐g‐MAH) were prepared in a twin screw extruder. The effect of the compatibilizer on the thermal properties and crystallization behavior was determined using differential scanning calorimetry analysis. The hold time was set to be equal to 5 min at 290°C. These conditions are necessary to eliminate the thermomechanical history in the molten state. The crystallization under nonisothermal conditions and the plot of Continuous‐Cooling‐Transformation of relative crystallinity diagrams of both PP and PA 66 components proves that PP is significantly affected by the presence of PP‐g‐MAH. From the results it is found that an abrupt change is observed at 2.5 wt % of PP‐g‐MAH as a compatibilizer and then levels off. In these blends, concurrent crystallization behavior was not observed for GFR PA66. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1620–1626, 2007