PA6/EPM/EPM-g-MAH共混物结构与性能研究

采用二元乙丙橡胶接枝马来酸酐(EPM-g-MAH)作为二元乙丙橡胶(EPM)增韧聚酰胺6(PA6)的增容剂,研究了PA6/EPM/EPM-g-MAH三元共混物的流变性能、力学性能和微观形态。结果表明,EPM-g-MAH可以与PA6发生增容反应生成接枝共聚物,改善了PA6和EPM的界面相容性。随着EPM-g-MAH含量的增加,共混物中分散相粒径更加细化,共混物的熔融峰温下降,缺口冲击强度显著提高,当EPM/EPM-g-MAH的配比为10/10时,共混物的冲击强度达到最大为47 kJ/m2,比纯PA6提高了8倍。     

Morphology—properties relationships in binary polyamide 6/rubber blends: Influence of the addition of a functionalized rubber

The modification of an amorphous random ethylene-propylene rubbery copolymer (EPM) has been accomplished by solution grafting of maleic anhydride molecules promoted by radical initiators, The resulting EPM-g-succinic anhydride (EPM-g-SA) and EPM have been used to obtain binary polyamide 6/EPM or polyamide 6/EPM-g-SA and ternary polyamide 6/EPM/EPM-g-SA blends by melt mixing. The formation of an EPM-g-PA6 graft copolymer during the blend preparation has been assumed. Different blend morphologies were observed by scanning electron microscopy (SEM) according to the nature and content of the rubber used. The tensile mechanical properties and the impact behavior of the prepared blends were investigated and correlated with the SEM analysis of the fracture surfaces. Binary and ternary blends containing 20 percent by weight of total rubber show a significant improvement of the impact properties at low temperature (?20°C) when the rubber is partly or entirely EPM-g-SA. In the case of PA6/EPM-g-SA (80/20) blend these results are related to the presence of rubbery domains of very small size strongly adherent to the PA6 matrix. In the case of 80/10/10 ternary blends, a much more complicated overall morphology is observed. Such morphology is characterized by the presence of large EPM domains, likely containing some EPM-g-PA6 graft molecules acting as an interfacial agent, and domains of EPM-g-PA6 of smaller size strongly adherent to the matrix as in the previous case.     

Reactive Compatibilization of Polyamide 6 with Isocyanate Functionalized Ethylene‐Propylene Copolymer

Reactive compatibilization of ethylene‐propylene copolymer functionalized with allyl (3‐isocyanato‐4‐tolyl) carbamate (TAI) isocyanate (EPM‐g‐TAI) and polyamide 6 (PA6) was investigated in this paper. FTIR analysis revealed the evidence of a chemical reaction between the end groups of PA6 and EPM‐g‐TAI. Thermal, rheological, morphological, and mechanical properties of the resultant system were examined. DSC analysis indicated that the crystallization of PA6 in PA6/EPM‐g‐TAI blends was inhibited, due to the chemical reaction that occurs at the interface of PA6 and EPM‐g‐TAI. Rheological measurement showed that complex viscosity and storage modulus of PA6/EPM‐g‐TAI were both dramatically enhanced compared to those of PA6/EPM at the same blending composition. After examining the morphology of both blending systems, smaller particle size, more homogeneous distribution of domains and improved interfacial adhesion between matrix and domains were observed in the compatibilized system. Mechanical properties such as tensile strength, Young's modulus, flexural strength and modulus, as well as notched and un‐notched impact strength of PA6/EPM‐g‐TAI blends were also found to improve gradually with increasing the content of grafted TAI.

Tensile modulus of the blends versus rubber content.     

马来酸酐及其酯接枝mPE增容PA 6/mPE共混物的制备

采用水相悬浮法制备了马来酸酐接枝茂金属聚乙烯(mPE-g-MAH)、马来酸二丁酯接枝茂金属聚乙烯(mPE-g-DBM),并以其为聚酰胺(PA)6/茂金属聚乙烯(mPE)共混物的增容剂,分别制备了PA 6/mPE/mPE-g-MAH,PA 6/mPE/mPE-g-DBM三元共混物。随着mPE-g-MAH,mPE-g-DBM用量的增加,三元共混物中PA 6的γ晶型增多,α晶型减少,PA 6与mPE的相容性加强,使三元共混物的韧性,特别是低温韧性提高。尽管mPE-g-DBM的接枝率比mPE-g-MAH高,但由于后者中的酸酐基团比前者的酯基更易与PA 6中的氨基、亚氨基反应,因此,mPE-g-DBM的增容、增韧效果不如mPE-g-MAH。     

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.     

Compatibilizing effect of maleated polypropylene on the mechanical properties and morphology of injection molded polyamide 6/polypropylene/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP=70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic modified montmorillonite (organoclay) were prepared using twin screw extruder followed by injection molding. Maleated polypropylene (MAH-g-PP) was used to compatibilize the blend system. The mechanical properties of PA6/PP nanocomposites were studied through tensile and flexural tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the fracture surface morphology and the dispersion of the organoclay, respectively. X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The thermal properties were characterized by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dynamic mechanical properties of PA6/PP nanocomposites were analyzed by using dynamic mechanical thermal analyzer (DMTA). The strength and stiffness of PA6/PP nanocomposites were improved significantly in the presence of MAH-g-PP. This has been attributed to the synergistic effect of organoclay and MAH-g-PP. The MAH-g-PP compatibilized PA6/PP nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PA6, PP and organoclay. TEM and XRD results revealed the formation of nanocomposites as the organoclay was intercalated and exfoliated. A possible chemical interaction between PA6, PP, organophilic modified montmorillonite and MAH-g-PP was proposed based on the experimental work.     

Effects of clay on phase morphology and mechanical properties in polyamide 6/EPDM-g-MA/organoclay ternary nanocomposites

In this study, both organoclay and EPDM-g-MA rubber were used to simultaneously improve the toughness and stiffness of polyamide 6 (PA6). We first prepared PA6/EPDM-g-MA/organoclay ternary nanocomposites using melt blending. Then the composites were subjected to traditional injection molding and so-called dynamic packing injection molding. The dispersion of clay, phase morphology, crystallinity and orientation of PA6 as well the mechanical properties were characterized by WAXD, SEM, DSC, 2D-WAXS and mechanical testing, respectively. The effects of clay on phase morphology and mechanical properties of PA6/EPDM-g-MA blends could be summarized as follows: (1) weakening interphase adhesion between PA6 and EPDM-g-MA rubber particles, resulted in increasing of rubber particle size, as the clay and rubber contents are low; (2) preventing coalescence of rubber domains, arisen in decreasing of rubber particle size, as the clay and rubber contents are high; (3) the blocking effect on the overlap of stress volume around rubber particles caused broadening of the brittle-ductile transition region and decrease of toughness, and (4) the effective stress transfer leading a better reinforcement when the interparticle distance is smaller than the critical value.     

接枝率对PVC/PA6-g-SMA共混物结构与性能的影响

采用熔融共混方法制备了聚氯乙烯（PVC）与不同接枝率苯乙烯-马来酸酐共聚物(SMA）接枝改性聚酰胺6（PA6-g-SMA）的共混物,研究了PA6-g-SMA接枝率对PVC/PA6-g-SMA共混物力学性能及凝聚态结构的影响。结果表明,接枝率越高,PA6-g-SMA与PVC的相容性越好,在PVC基体中能以更小的相畴均匀分散,对PVC的增韧增强作用越明显;当PA6-g-SMA的接枝率为5.12 %,添加量为15 ％（质量分数,下同）时,共混物的冲击强度为64.7 kJ/m2,拉伸强度为55 MPa。     

Ternary nylon-6/rubber/modified rubber blends: Effect of the mixing procedure on morphology, mechanical and impact properties

Ternary polyamide-based blends have been prepared by adding to nylon-6 (PA6) an ethylene-propylene random copolymer (EPM) and the same EPM functionalized by inserting onto its backbone maleic anhydride groups (EPM-g-SA). Two kinds of processing have been used: (a) one-step mixing in which the three components were simultaneously introduced in the mixer; (b) two-step mixing in which the two rubbers EPM and EPM-g-SA were separately premixed before the final mixing with PA6. Also binary PA6/EPM-g-SA blends have been prepared to compare their properties with those of the ternary one.

Mechanical tensile characterization at room temperature and impact Izod tests at different temperatures as well as a morphological analysis of smoothed samples have been performed on all the blends. It has been shown by a model reaction that both in binary and ternary blends an EPM-g-PA6 graft copolymer is formed, which acts as an interfacial agent between the rubbery dispersed phase and the polyamide matrix. The blends obtained by the one-step mixing showed a gross morphology and a very poor impact resistance, whereas the ones prepared by the two-step mixing exhibited very fine morphologies and excellent impact performances. In addition, as shown at least in the case of one ternary blend, there seems to be good morphological stability of these materials after a second processing. This has been attributed to the influence of the interfacial agent formed during the melt mixing of the two premixed rubbers with PA6.     

Influence of Grafting Degree on the Morphology and Mechanical Properties of PA6/POE-g-GMA Blends

Poly(ethylene-1-octene) (POE) was functionalized to varying degrees with glycidyl methacrylate (GMA) by melt grafting processes. Fourier transform infrared spectra (FT-IR) and ¹H NMR spectra confirmed that glycidyl methacrylate was successfully grafted onto the POE. The data from GPC measure demonstrated that POE chains degraded during grafting process. The POE-g-GMA elastomers were used to toughen nylon. The mechanical properties, fracture surface morphology and the dispersal phase size were investigated. Results showed that the grafting degree strongly influenced the morphology, mechanical properties and the dispersal phase size of PA6/POE-g-GMA blends.     

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.     

EPM-g-MAH及玻璃纤维对聚酰胺6的增韧增强研究

采用二元乙丙橡胶接枝马来酸酐(EPM-g-MAH)及玻璃纤维(GF)对聚酰胺6(PA6)进行共混改性,并对复合材料的力学性能和微观结构进行了表征。结果表明:PA6/EPM/EPM-g-MAH复合材料的形态结构得到明显改善,弹性体分散相粒径细化且分布均匀;增韧PA6所用的EPM-g-MAH适宜的粒径范围是0.2～0.7μm;当PA6/EPM/EPM-g-MAH/GF为80/10/10/(30～40)时,复合材料的缺口冲击强度可达到25.4 kJ/m2,拉伸强度可达到73 MPa。     

The Improvement of Compatibility in Glass Fiber Reinforced PA6/PP Blends

Abstract

Rheological properties (melt flow index and melt stability), mechanical properties (tensile strength, flexural strength and impact) of polyamide (PA6) polypropylene (PP) blends were investigated. Influence of potential compatibilizors: 4,4′-diphenyhnethane carbodiimide (OCDI), 4,4′-diphenylmethane bismaleimide (BMI) and 2,2′-(1,4-pheaylene)-bisoxazoline (OX) on mechanical properties and thermostability of initial and glass reinforced polymer blends was also investigated too. We tried to study the structure of glass fiber reinforced composites by mercury intrusion porosimitry. The influence of compatibilizors on molecular weight of PA6 was studied by GPC, on chemical structure of blends was investigated by NMR and IR-spectroscopy. Addition of OCDI and OX (chain extenders) preserves the product formation as the react with the active and carbonyl groups of PA6. BMI has lower reactivity. Grafting of BMI to PP chains improves compatibility in PA6/PP blend and increases PP adhesion to glass fiber.     

PA6/ABS/PC合金的研制

以PA6，ABS，PC为基础树脂，ABS-g-MAH为增容剂，二叔丁基过氧化物为引发剂，并加入改性剂等助剂，制备了PA6／ABS／PC合金，研究了增容剂的种类及含量，引发剂的种类，PA6的粘度，ABS的牌号及改性剂的含量对PA6／ABS／PC合金性能的影响。结果表明，采用1．0％－1．2％的ABS-g-MAH,30%的相对粘度2．8－3．0的PA6，40％的1300型PC，28％的ABS及0．5％的改性剂制得的PA6／ABS／PC合金优于日本孟山都公司的PA6／ABS合金。     

Investigation on the polyamide 6/organoclay nanocomposites with or without a maleated polyolefin elastomer as a toughener

Polyamide 6 (PA 6)-based nanocomposites were prepared using a melt-mixing technique in this study. One commercial organoclay (denoted 30B) and one maleated polyolefin elastomer (denoted POEMA) served as the reinforcing filler and toughener, respectively. The X-ray diffraction (XRD), scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS) and transmission electron microscopy (TEM) results confirmed the nano-scaled dispersion of 30B in the composites. Different mixing sequences presented similar phase morphology for the same formulated nanocomposites. XRD results also revealed that both 30B and POEMA would induce the formation of γ form PA 6 crystal, with 30B exhibiting a higher efficiency. Differential scanning calorimetry (DSC) results indicated that the addition of 30B altered the crystallization kinetics of PA 6, which was mainly attributed to the prevailing formation of γ form crystal. Complex melting behaviors were observed for neat PA 6 and the nanocomposites. These complex behaviors are associated with different polymorphs and the ‘melting-recrystallization-remelting’ phenomenon. Moderate thermal stability enhancement of PA 6 after adding 30B and/or POEMA was confirmed using thermogravimetric analysis (TGA). The storage modulus, Young's modulus and tensile strength of PA 6 were increased after adding 30B. However, these properties declined after further incorporation of POEMA. The different-processed PA 6/30B/POEMA nanocomposites displayed balanced tensile properties and toughness between those of neat PA 6 and PA 6/30B nanocomposite.     

尼龙1010／乙丙共聚物共混体系形态与性能研究

在过氧化二异丙苯（ＤＣＰ）的引发下，用反应挤出的方法制备了乙丙共聚物接枝甲基丙烯酸环氧丙酯（ＥＰＭ－ｇ－ＧＭＡ）。用Ｂｒａｂｅｎｄｅｒ单螺杆挤出机制备了不同组成的ＥＰＭ／尼龙１０１０及ＥＰＭ－ｇ－ＧＭＡ／尼龙－１０１０的共混物，用电子显微镜观察了不同共混组成的形态，与ＥＰＭ／尼龙１０１０共混体系相比，ＥＰＭ－ｇ－ＧＭＡ／尼龙１０１０体系中ＥＰＭ在尼龙１０１０中分散相尺寸明显降低，ＥＰＭ－ｇ－ＧＭＡ     

PA6/PP/SEBS-g-MAH共混物的相容性研究

采用马来酸酐接枝(氢化苯乙烯/丁二烯/苯乙烯)共聚物(SEBS-g-MAH)作为增容剂,研究了增容剂用量对尼龙6/聚丙烯(PA6/PP)共混体系相态结构、力学性能的影响,以及在相同增容剂用量下不同PA6、PP配比对体系相形态的影响。结果表明,SEBS-g-MAH中的酸酐基团能与PA6末端的氨基发生化学反应,在PA6和PP的内表面形成PA6-SEBS接枝共聚物,明显改善了两相的界面相容性,并使共混物的力学性能得到显著提高。共混物冲击断面形貌的分析表明,共混物发生了明显的脆韧转变。     

马来酸接枝PP增容PA6/PP合金的研究

研究了马来酸接枝聚丙烯(MAC-g-PP)的熔体流动速率(MFR)、接枝率与接枝配方的关系,PA6/接枝PP/PP合金的力学性能与接枝PP的特征参数、用量,以及PA6/(PP 接枝PP)配比的关系。结果表明,合金的力学性能随接枝PP的MFR增加而提高,与接枝率无关,接枝PP用量有一最佳值,高MFR的MAC-g-PP能显著改善合金的冲击韧性。     

相容剂C的辐射合成及在PA6／ABS合金中的应用

本工作采用SAN粉料作基材、甲基丙烯酸缩水甘油酯（GMA）作接枝单体,运用辐射接枝技术合成了相容剂C并应用于PA6／ABS合金。考察了GMA质量分数、辐射剂量对接枝率的影响,以及相容剂C、助剂D和PA6质量分数等对合金性能的影响。通过测试结果和透射电子显微镜（TEM）照片分析表明：用辐射法合成相容剂C是成功的,能有效地提高PA6／ABS合金性能,表现出优良的增容效果。     

A new method of preparation of a rubber-modified polyamide directly during caprolactam polymerization

A new method to obtain a rubber-modified polyamide 6 (PA6) directly during the polymerization of the caprolactam (CL) is described. Binary and ternary blends containing ethylene-propylene random copolymers (EPM) and/or a fictionalized EPM rubber (EPM-g-SA) were prepared and their morphology as well as their mechanical properties were investigated as function of composition and reaction conditions. It was found that the morphology of the blends is strongly dependent on the method of preparation. More complex structures are observed in blends obtained with the “Solution” preparation. For a better resolution of the morphology, the smooth ultramicrotomed surfaces were exposed to boiling xylene before SEM (scanning electron microscopy) examination. The rubbery phases are selectively dissolved whereas the PA6 matrix is left. The tensile mechanical properties and the Izod impact behavior are related to the mode and state of dispersion of the rubbery components. The impact properties of ternary PA6/EPM/EPMg-SA (80/18/2) and (80/15/5) blends, prepared during the CL polymerization are comparable to those of similar blends obtained by usual melt mixing procedures.