PP-g-(MAH/VAc)接枝物对PP/PA6体系的增容作用

通过扫描电镜、差示扫描量热仪和力学性能测试等方法研究了聚丙烯接枝马来酸配和酷酸乙烯酷(PP-g-MAH/VAc)对聚丙烯康酸胺6(80/20}共混体系的增容效果。结果表明,PP-g-(MAH/DAc)用于PP/PA6共混体系,分散相PA6的微区尺寸可以减小到5μm以下,相应地提高了共混物的断裂伸长率、拉伸强度和冲击强度。使用接枝率为5.3%的PP-g-(MAH/VAc)作为相容剂,当用量为8%时,体系的拉伸强度为60.88MPa,断裂伸长率为558%,冲击强度为5.28KJ/㎡.DSC分析表明,PP/PA6共混体系各组分相互促进成核,结晶度降低。FTIR结果表明,PP-g-(MAH/VAc)中的MAH上的酸配基团与PA6中的酸胺键发生了化学反应从而改善了体系的相容性。     

Preparation and characterization of syndiotactic polystyrene/ethylene‐propylene copolymer blends

The reactive compatibilization of syndiotactic polystyrene (sPS)/oxazoline‐styrene copolymer (RPS)/maleic anhydride grafted ethylene‐propylene copolymer (EPR‐MA) blends is investigated in this study. First, the miscibility of sPS/RPS blends is examined by thermal analysis. The cold crystallization peak (T_cc) moved toward higher temperature with increased PRS, and, concerning enthalpy relaxation behaviors, only a single enthalpy relation peak was found in all aged samples. These results indicate that the sPS/RPS blend is miscible along the various compositions and RPS can be used in the reactive compatibilization of sPS/RPS/EPR‐MA blends. The reactive compatibilized sPS/RPS/EPR‐MA blends showed finer morphology than sPS/EPR‐MA physical blends and higher storage modulus (G') and complex viscosity (η*) when RPS contents were increased. Moreover, the impact strength of sPS/RPS/EPR‐MA increased significantly compared to sPS/EPR‐MA blend, and SEM micrographs after impact testing show that the sPS/RPS/EPR‐MA blend has better adhesion between the sPS matrix and the dispersed EPR‐MA phase. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2084–2091, 2002     

ABS/PA6共混体系的反应性增容研究

用少量苯乙烯-马来酸酐(SMA)作为相容剂改善ABS/PA6共混体系的相容性,研究了共混体系(固定ABS/PA6质量比为70/30)中相容剂的最佳用量,以及随相容剂含量变化引起的体系形态结构和力学性能变化情况,同时探讨了体系组成与性能关系的微观机理。还研究了环境因素对ABS/PA6共混体系性能的影响。     

Toughening and compatibilization of polypropylene/polyamide‐6 blends with a maleated–grafted ethylene‐co‐vinyl acetate

In this article, maleated–grafted ethylene‐co‐vinyl acetate (EVA‐g‐MA) was used as the interfacial modifier for polypropylene/polyamide‐6 (PP/PA6) blends, and effects of its concentration on the mechanical properties and the morphology of blends were investigated. It was found that the addition of EVA‐g‐MA improved the compatibility between PP and PA6 and resulted in a finer dispersion of dispersed PA6 phase. In comparison with uncompatibilized PP/PA6 blend, a significant reduction in the size of dispersed PA6 domain was observed. Toluene‐etched micrographs confirmed the formation of interfacial copolymers. Mechanical measurement revealed that the addition of EVA‐g‐MA markedly improved the impact toughness of PP/PA6 blend. Fractograph micrographs revealed that matrix shear yielding began to occur when EVA‐g‐MA concentration was increased upto 18 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3300–3307, 2006     

Compatibilization of Polyamide‐6/Polyarylate Blends by Means of an Ionomer

Summary: Polyamide‐6 (PA6)/polyarylate of bisphenol A (PAr) blends rich in PA6 and modified with an additional 15% poly[ethylene‐co‐(methacrylic acid)] partially neutralized with zinc (PEMA‐Zn) as a compatibilizer were obtained by melt mixing. Their phase structure, morphology, and mechanical performance were compared with those of the corresponding binary blends. The ternary blends were composed of a PA6 amorphous matrix and a dispersed PAr‐rich phase in which reacted PA6 and PEMA‐Zn were present. Additionally, minor amounts of a crystalline PA6 phase, and a PEMA‐Zn phase were also present. The chemical reactions observed led to a clear decrease in the dispersed particle size when PEMA‐Zn was added, indicating compatibilization. Consequently, the mechanical behavior of the blends with PEMA‐Zn improved, leading, mainly in the case of the blend with 10% PAr, to significant increases in both ductility and impact strength with respect to those of the binary blends. These increases were more remarkable than the slight decrease in stiffness as a consequence of the rubbery nature of the compatibilizer.

Cryogenically fractured surface of the PA6/PAr‐PEMA‐Zn 70/30‐15 ternary blend.     

聚酰胺6—聚醚嵌段共聚物增韧改性

以聚四氢呋喃醚为软段制备大分子活化剂,引发己内酰胺阴离子聚合,合成了聚酰胺６－聚醚嵌段共聚物,并考察大分子活化剂种类、用量对聚合物力学性能的影响。结果表明,所得制品在保持一定强度、硬度的条件下,冲击性能可大幅度提高,取的了较好的增韧效果。     

Compatibilization of PA6/PPO blend with carboxylated poly(styrene) compounds

PA6/PPO 70/30 blends were reactively compatibilized using carboxylated polystyrene (PS) and poly(styrene‐block‐4‐methylstyrene) with various degrees of carboxylation. The high carboxylation of PS (up to about 50%) caused a decrease of dispersed PPO dimensions with a simultaneous deterioration of properties, especially of toughness and elongation. The best mechanical behavior was found for PS with 1% degree of carboxylation and for neat PS. On the other hand, degrees of carboxylation higher than 50% caused an increase in particle size. This was most significant for block copolymers, where a marked change in size and shape occurred, from spherical particles of about 1 μm in size to large, elongated particles about 50 μm long or a similar rough cocontinuous structure. The deteriorated mechanical behavior is tentatively explained by unsuitable properties of the reactively formed compatibilizer and thus of the interface. The enhanced rigidity of highly carboxylated poly(4‐methylstyrene) chains (and its product of grafting with PA6), causing its decreased emulsification ability together with the expected rigid interface, which probably suppresses breakup of the PPO phase, may be responsible for the increase of the dispersed PPO dimensions found. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2273–2280, 2001     

Compatibilization of polyethylene/polyamide 6 blends with oxazoline‐functionalized polyethylene and styrene ethylene/butylene styrene copolymer (SEBS)

Study was made of the compatibilization of polyethylene/polyamide 6 (PE/PA6) blends with a ricinoloxazoline maleinate grafted polyethylene and styrene ethylene/butylene styrene copolymer. The blends were prepared in a twin‐screw midiextruder, and the specimens for mechanical tests were injection molded with a mini‐injection molding machine. The effect of compatibilizing on the mechanical properties and the morphology of the blends was studied. The toughness and ductility of the blends were substantially improved as a result of the compatibilization. Simultaneously, the strength and stiffness were slightly reduced. Morphological studies showed that the particle size was reduced and the adhesion of the dispersed phase to the matrix was improved by the compatibilization. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1443–1450, 1999     

Compatibilization of nitrile‐butadiene rubber/ethylene‐propylene‐diene monomer blends by mercapto‐modified ethylene‐vinyl acetate copolymers

Mercapto‐modified ethylene‐vinyl acetate (EVASH) has been employed as a reactive compatibilizing agent for nitrile‐butadiene rubber (NBR)/ethylene‐propylene‐diene monomer (EPDM) blends vulcanized with a sulfur/2,2′‐dithiobisbenzothiazole (MBTS) single accelerator system and a (sulfur/MBTS/tetramethylthiuram disulfide (TMTD) binary accelerator system. The addition of 5.0 phr EVASH resulted in a significant improvement in the tensile properties of blends vulcanized with the sulfur/MBTS system. In addition to better mechanical performance, these functionalized copolymers gave rise to a more homogeneous morphology and, in some cases, better aging resistance. The compatibilization was not efficient in blends vulcanized with the S/MBTS/TMTD binary system, probably because of the faster vulcanization process occurring in this system. The good performance of these EVASH samples as compatibilizing agents for NBR/EPDM blends is attributed to the higher polarity of these components that is associated with their lower viscosity. Dynamic mechanical analysis also suggested a good interaction between the phases in the presence of EVASH. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1404–1412, 2004     

聚酰胺6废丝的反应挤出改性研究

通过反应挤出的方法，用环氧树脂、异氰酸酯、环氧酚醛和酚醛等多种树脂对回料聚酰胺6进行改性以提高力学性能。指出了不同体系的反应机理和优缺点。结果表明：环氧树脂对回料聚酰胺6有理想的效果：抗冲击性能提高一倍，拉伸强度也有大幅度提高。催化剂对反应挤出体系是必不可少的。差示扫描量热分析表明改性后的聚酰胺6的熔点有明显提高。结晶度有所下降。     

Compatibilization of Poly(propylene)/Polyamide 6 Blends with Functionalized Poly(propylene)s Prepared with Metallocene Catalyst

Summary: Propylene was copolymerized with 10‐undecen‐1‐ol using dimethylsilanylbis(2‐methyl‐4‐phenyl‐1‐indenyl)zirconium dichloride as catalyst and MAO and TIBA as cocatalysts. Comonomer incorporations from 0.1 to 0.9 mol‐% (0.5 to 3.6 wt.‐%) were obtained. These hydroxyl functionalized copolymers were applied as compatibilizers to PP/PA6 blend with a composition of 70/30. For comparison, hydroxyl functionalized polyethylene prepared with metallocene catalyst and commercial MAH grafted ethylene butyl acrylate (E/BA/MAH) and poly(propylene) (PP‐g‐MAH) were also used as compatibilizers. Effects of the compatibilizers on morphology and mechanical and thermal properties of the blends were studied. Enhanced adhesion between the blend components was observed in morphology and dynamic mechanical studies. Although improvement in toughness was not as pronounced as expected, there were indications that the hydroxyl functionalized propylene copolymers prepared with metallocene catalysts could serve as a new type of compatibilizer in polymer blends.

SEM micrograph (5 000×) of an PP/PA6/PP‐co‐OH4 blend.     

Morphology and mechanical properties of polyamide‐6/K resin blends

Mechanical properties and morphological studies of compatibilized blends of polyamide‐6 (PA‐6)/K resin grafted with maleic anhydride (K‐g‐MAH) and PA‐6/K resin/K‐g‐MAH were investigated as functions of K resin/K‐g‐MAH and dispersed phase K resin concentrations, and all the blends were prepared using twin screw extruder followed by injection molding. Scanning electron microscopy (SEM) were used to assess the fracture surface morphology and the dispersion of the K resin in PA‐6 continuous phase, the results showing extensive deformation in presence of K‐g‐MAH, whereas, uncompatibilized PA‐6/K resin blends show dislodging of K resin domains from the PA‐6 matrix. Dynamic mechanical thermal analysis (DMTA) test reveals the partially miscibility of PA‐6 with K‐g‐MAH, and differential scanning calorimetry (DSC) results further identified that the introduction of K‐g‐MAH greatly improved the miscibility between PA‐6 and K resin. The mechanical properties of PA‐6/K resin blends and K‐g‐MAH were studied through bending, tensile, and impact properties. The Izod notch impact strength of PA‐6/K‐g‐MAH blends increase with the addition of K‐g‐MAH, when the K‐g‐MAH content adds up to 20 wt %, the impact strength is as more than 6.2 times as pure PA‐6, and accompanied with small decrease in the tensile and bending strength less than 12.9% and 17.5%, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Toughening of Polystyrene with Ethylene‐Propylene‐Diene Terpolymer (EPDM) Compatibilized by Styrene‐Butadiene‐Styrene Block Copolymer (SBS)

Summary: Polystyrene (PS) was toughened with ethylene‐propylene‐diene terpolymer (EPDM) in the presence of styrene‐butadiene‐styrene block copolymer (SBS). Incorporation of SBS into the PS/EPDM blends clearly improved the impact properties. For PS/EPDM/SBS (mass ratio: 69/21/10) blends, the notched Charpy impact strength reached a maximum value of 26.3 kJ/m². Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that SBS was distributed on the interface between PS and EPDM. Butanone extraction and FTIR analysis found that there was a grafting reaction between PS and EPDM phase during melt compounding. Shearing and processing rheological behaviors of blends were evaluated with a Haake capillary rheometer and a torque rheometer, respectively.

     

聚酰胺6／乙烯-乙烯醇无规共聚物共混体系的相容性及性能研究

研究了不同比例乙烯-乙烯醇无规共聚物(EVOH)和聚酰胺6(PA6)共混物的相容性及性能。扫描电子显微镜下观察结果表明二者具有较好的相容性;红外光谱分析和流变实验证实了EVOH与PA6分子间氢键的存在,氢键的作用会随着EVOH含量的增加而增强;阻透性能的测试表明在PA基体中加入EVOH会极大提高基体的阻透性,在EVOH基体中加入少量的PA6对EVOH的阻透性影响很小。     

Study on morphology of compatibilized poly (vinyl chloride)/ultrafine polyamide‐6 blends by styrene–maleic anhydride

Ultrafine polyamide‐6 (UPA6) with a size of 4–8 μm was prepared via jet‐milling. Blends of poly (vinyl chloride) (PVC) and UPA6 using a reactive copolymer styrene–maleic anhydride (SMA‐18%) were prepared. The change in morphology and structure of the blends were studied using differential scanning calorimetry, scanning electron microscopy, and X‐ray diffraction. The blend behavior was also determined experimentally using dynamic mechanical analysis. Contrasted to the original PA6, the crystallinity of the UPA6 decreased, the size of its crystallites were reduced, and its melting point decreased to 175°C. In all blends, PVC formed the continuous matrix phase. SMA is miscible with PVC and tends to be dissolved in the PVC phase during the earlier stages of blending. The dissolved SMA has the opportunity to react with PA6 at the interface to form the desirable SMA‐g‐PA6 copolymer. This in situ formed SMA‐g‐PA6 graft copolymer tends to anchor along the interface to reduce the interfacial tension and results in finer phase domains. Cocrystallity existed in PVC/(UPA6/SMA) at a ratio of 82/(18/5). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 850–854, 2005     

共混方式对ABS／PA6／SMA共混体系形态和力学性能的影响

以苯乙烯-马来酸酐共聚物（SMA）为反应增容剂，研究不同共混工艺和ABS／PA6配比对三共混体系聚集态结构和力学性能的影响。结果表明：SMA对共混体系增容效果显著，并明显改善了ABS／PA6共混体系的力学性能。其中当PA6用量为30份和40份时，SMA先与ABS共混再与PA6共混的方式所生成共混物的性能优于SMA先与PA6共混再与ABS共混的方式。PA6用量为30份时性能最好，共混物的分散相尺寸达到最小值0．31μm，分散相颗粒PA6周长面积比为最大值0．46，拉伸强度和冲击强度也分别为最大值63．2MPa和8．29kJ／m^2。当PA6用量达到45份时，共混方式对共混物的力学性能影响不大。研究表明，当ABS为连续相时，共混方式可以强烈地影响ABS／PA6共混物体系的聚集态结构和力学性能，而PA6和ABS向共连续相发展时，共混方式对ABS／PA6聚集态结构和力学性能则影响不大。     

Compatibilization and Properties of EVA Copolymers Containing Surface‐Functionalized Cellulose Microfibers

Cellulose microfibers were modified with two different bi‐functional monomers. Composites of EVA copolymer with modified and unmodified cellulose were prepared by melt mixing. The samples were analyzed by SEM, XRD, FT‐IR, DSC, TGA, DMTA and tensile mechanical tests. SEM showed that the presence of reactive groups on cellulose surface enhanced the compatibility, improving the fiber/matrix interfacial adhesion. FT‐IR disclosed the occurrence of chemical reactions between the functionalized cellulose and polymer chains. The incorporation of fibers affected the crystallization behaviour and crystallinity of the polymer matrix. Composites with GMA modified cellulose displayed better compatibility, higher thermal and mechanical properties.

     

Compatibilization of polypropylene/nylon 6 blends with a polypropylene solid‐phase graft

The compatibilization of polypropylene (PP)/nylon 6 (PA6) blends with a new PP solid‐phase graft copolymer (gPP) was systematically studied. gPP improved the compatibility of PP/PA6 blends efficiently. Because of the reaction between the reactive groups of gPP and the NH₂ end groups of PA6, a PP‐g‐PA6 copolymer was formed as a compatibilizer in the vicinity of the interfaces during the melting extrusion of gPP and PA6. The tensile strength and impact strength of the compatibilized PP/PA6 blends obviously increased in comparison with those of the PP/PA6 mechanical blends, and the amount of gPP and the content of the third monomer during the preparation of gPP affected the mechanical properties of the compatibilized blends. Scanning electron microscopy and transmission electron microscopy indicated that the particle sizes of the dispersed phases of the compatibilized PP/PA6 blends became smaller and that the interfaces became more indistinct in comparison with the mechanical blends. The microcrystal size of PA6 and the crystallinity of the two components of the PP/PA6 blends decreased after compatibilization with gPP. The compatibilized PP/PA6 blends possessed higher pseudoplasticity, melt viscosity, and flow activation energy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 420–427, 2004     

EAA对PE-HD/水滑石复合材料的反应增容作用

利用熔融共混法制备了乙烯-丙烯酸共聚物（EAA）/水滑石（LDH）母粒和高密度聚乙烯（PE-HD）/LDH复合材料;研究了EAA与LDH之间的相互作用以及EAA在复合材料中的增容作用。结果表明,EAA能使LDH层间可交换的阴离子碳酸根脱出,且与LDH产生化学键作用形成羧酸金属离子键,减小LDH片层之间的相互作用;EAA能有效减小LDH的晶体衍射峰,使LDH层状堆砌、长程有序的晶体结构被打破;EAA对复合材料有很好的增容作用,能明显增强LDH与PE-HD之间的界面黏合,促进LDH在基体中的有效分散;力学性能测试表明,添加EAA的复合材料比没有添加EAA的复合材料的力学性能有明显提高,且能使强度和韧性同时提高。     

官能化接枝共聚物增容PA6/PS共混物的研究

将苯乙烯(St)和甲基丙烯酸环氧丙酯（GMA）通过乳液聚合接枝到聚丁二烯(PB)上,形成核壳结构接枝共聚物PB-g-PS和官能化接枝共聚物PB-g-(St-GMA),并考察了其对聚酰胺6/聚苯乙烯(PA6/PS)共混物相容性的影响。对共混物的流变性能、动态力学性能和形态结构进行了分析,结果表明,引入1 %官能化单体GMA后,共混物的平衡扭矩增加,PA6与PS两相的玻璃化转变温度差值变小,分散相尺寸明显减小,PB-g-(St-GMA)可以改善PA6/PS共混物的相容性。继续增加PB-g-(St-GMA)中GMA含量时,共混物相容性下降。