尼龙1212/66/EPDM-g-MA/DIDP/BSBA共混体系的制备与力学性能

将尼龙1212盐和尼龙66盐按照9：1（质量比）的配比合成了尼龙1212／66共聚物。选择EPDM—g—MA和两种不同的小分子增塑剂邻苯二甲酸二异癸酯／N-丁基苯磺酰胺，采用共混挤出的方法，制备了尼龙1212／66／EPDM—g—MA／DIDP／BSBA共混合金，并对其力学性能进行了研究。结果表明，随着EPDM—g—MA用量的增加，共混合金的冲击强度明显提高。当EPDM—g—MA质量系数为10％时，缺口冲击强度为86．8kJ／m^2，是尼龙1212／66共聚物的17倍左右；拉伸强度保持率是尼龙1212／66共聚物的90％左右。     

尼龙1212/SEBS-g-MA/DIDP/BSBA共混体系热行为的研究

利用差示扫描量热(DSC)、热失重(TG)和微分热失重(DTG)，研究了尼龙1212/SEBS-g-MA／DIDP／BSBA共混体系共混物的热行为和降解过程。实验结果表明，共混体系均为单一的熔融行为，加入的SEBS-g-MA使熔点和熔融热下降；热降解为二步降解过程。     

(PA1010/66)/SEBS-g-MAH/DIDP/BSBA共混物的制备与性能研究

将尼龙(PA)1010盐和PA66盐按照质量比为9∶1的比例制备了PA1010/66共聚物。选择(苯乙烯/乙烯-丁烯/苯乙烯)共聚物接枝马来酸酐(SEBS-g-MAH)和两种小分子增塑剂邻苯二甲酸二异癸酯、N-丁基苯磺酰胺(D IDP、BSBA),采用共混挤出法制备了(PA1010/66)/SEBS-g-MAH/D IDP/BSBA共混物,并对其力学性能进行了研究。结果表明,随着SEBS-g-MAH含量的增加,共混物的冲击强度明显提高。当SEBS-g-MAH质量分数为15%时,其缺口冲击强度为72.7 kJ/m2,是PA1010/66共聚物的16倍左右;拉伸强度保持率是PA1010/66共聚物的83%左右。通过SEM研究发现,SEBS-g-MAH对PA1010/66共聚物的增韧机理为银纹剪切带增韧机理。     

尼龙1212/SEBS-g-MAH/DIDP/BSBA共混体系流变性能的研究

研究了尼龙1212／SEBS-g-MAH／DIDP／BSBA共混体系的流变性能。结果表明：共混体系的非牛顿指数n小于1，且n随SEBS-g-MAH用量的增加而减少，即非牛顿性增强；共混物熔体服从假塑性流体的流动规律，表观粘度随剪切速率的增加而降低；温度升高，表观粘度降低。     

尼龙1212/MBS/环氧乙烷共混体系的制备和性能研究

采用核-壳聚合物／FIBS为增韧剂和环氧乙烷（Epoxy）为相容剂,采用共混挤出的方法,制备了尼龙1212／MBS／Epoxy共混合金,测定了力学性能。结果表明,核-壳聚合物MBS加入的质量分数为20％NEpoxy的质量分数为3％时,共混体系的拉伸强度和冲击强度都同时提高并到达最大值,其拉伸强度和冲击强度分别是64．2MPa和25．6kJ／m^2,分别是纯尼龙1212的1．33倍和6．1倍,即韧性提高了5．1倍且拉伸强度也有所提高。用SEN对共混物的表面特性进行了研究。     

尼龙1212/EPDM-g-MAH共混体系的制备及性能研究

制备了尼龙（PA）1212／EPDM－g-MAH共混物，并对其力学性能、热性能及共混形态进行了研究，结果表明，增韧剂的加入使共混物的缺口冲击强度显著增大，当增韧剂含量为20％时，缺口冲击强度为74．98kJ/m^3，是纯PA1212的13．5倍；用二甲苯处理过的共混物试样断面很不平坦，有很多孔洞和类纤维体，说明弹性体粒子以球状分散于基体树脂中。     

PA6/MPEG共混物的制备及性能研究

利用聚乙二醇(PEG)的端羟基与马来酸酐(MAH)进行化学反应，制备了聚乙二醇双马来酸酯(MPEG)。通过熔融共混的方法在PA6中混入质量分数为2％-10％的MPEG，制得PA6／MPEG共混物。MPEG的加入可起到增塑作用。随其加入量的增加，共混物的拉伸强度和洛氏硬度降低，缺口冲击强度增大，同时共混物的亲水性明显提高。     

PS／PA6／SEBS-g-MA共混体系的非等温结晶行为、流变性能及力学性能的研究

聚苯乙烯（PS）／聚酰胺（PA6）共混物中加入5份的马来酸酐接枝氢化苯乙烯-丁二烯嵌段共聚物（SEBS-g—MA），提高了PA6的结晶度，但使结晶时问延长。非等温结晶动力学研究表明，在结晶前期，SEBS-g—MA可能对PS／PA6中的PA6有异相成核的作用，结晶后期，PS／PA6和PS／PA6／SEBS-g—MA的结晶方式基本一致。加入SEBS-g—MA，原位生成SEBS-g-PA6，提高了共混物的复数黏度（η^＊）和储能模量（G’），在G’相同的情况下，PS／PA6／SEBS-g-MA的损耗模量（G″）低于PS／PA6。PS／PA6／SEBS-g—MA（50／50／5）共混物的冲击强度较PS／PA6（50／50）略有降低，拉伸强度略有提高。当SEBS-g-MA的用量大于5份后，拉伸强度降低，断裂伸长率增加，共混物的冲击强度随SEBS-g—MA含量的增加不断提高，PS／PA6／SEBS-g—MA（50／50／20）的冲击强度提高了2．4倍。     

PFPA1212/SEBS-g-MAH共混合金力学性能和微观结构的研究

制备了石油发酵尼龙1212／SEBS－g-MAH共混合,工对其力学性能和微观结构进行了研究。结果表明，随着增韧剂含量的增加，共混合金的制品冲击强度显著提高，当增韧剂含量为25％时，缺口冲击强度为61.26kJ/m^2，是纯尼龙1212的15倍，拉伸强度保持率是纯尼龙1212的90％。微观结构研究表明，尼龙1212的断裂属于韧性断裂，增韧后的尼龙1212制品冲击断面有明显的应力发白现象，冲击强度提高的主要原因在于应力集中点的增多。     

超韧PA6/ABS合金的制备

以苯乙烯-马来酸酐（SMA）共聚物为增容剂，考察了ABS及SMA的含量对PA6／ABS共混体系的力学性能的影响；并利用SEM研究了PA6／ABS冲击断面的相结构。研究表明：SMA是PA6／ABS共混体系的有效增容剂。随着其含量的增加，分散相ABS粒子的尺寸减小，分散更加均匀，能显著地改善PA6／ABS共混物的冲击、拉伸和弯曲性能。在该共混体系中，ABS含量的增加能够大幅度地提高PA6／ABS共混物的冲击韧性；但当ABS含量超过10％时，将使PA6／ABS共混物的拉伸和弯曲性能明显下降。SMA的添加量为0．5％，且质量比为90／10的PA6／ABS共混体系能保持较好的加工性能，制备的PA6／ABS合金具有最佳的综合力学性能和超高韧性．Izod缺口冲击强度高达1200J／m。     

Morphology of nylon 1212 toughened with a maleated EPDM rubber

BACKGROUND: Polyamides, or nylons, are an attractive class of engineering polymers due to their excellent strength and stiffness, low friction and chemical and wear resistance. However, they are highly notch‐sensitive, i.e. they are often ductile in the un‐notched state, but fail in a brittle manner when notched. A super‐tough nylon 1212 was prepared by blending nylon 1212 with ethylene propylene diene monomer (EPDM) grafted with maleic anhydride (MA). The morphologies of Izod impact fracture surfaces as well as xylene‐etched surfaces of the nylon were thoroughly investigated using scanning electron microscopy (SEM). RESULTS: The fracture morphology and the impact strength of the nylon 1212 blends are very well correlated. The impact fracture surface of the blends exhibits certain characteristic features, such as the observation of fiber‐like sticks when etched with boiling xylene, formed during the impact fracture process. SEM images of xylene‐etched surfaces as well as the results of X‐ray energy dispersive spectroscopy suggest that the successful toughening of nylon 1212 with EPDM‐graft‐MA is due to the reaction between the anhydride of EPDM‐graft‐MA and the amine end‐groups of nylon 1212, leading to the formation of a homogenous graft copolymer system. CONCLUSION: The copolymer system, acting as a surfactant, reduces the interfacial tension between nylon 1212 and EPDM‐graft‐MA and produces a highly compatible super‐tough nylon 1212. Copyright © 2008 Society of Chemical Industry     

Effects of maleated styrene–(ethylene‐co‐butene)–styrene on the morphology and mechanical and thermal properties of polystyrene/polyamide 1212 blends

Polystyrene (PS)/polyamide 1212 (PA 1212) blends were compatibilized with a maleated triblock copolymer of styrene–(ethylene‐co‐butene)–styrene (SEBS‐g‐MA). Scanning electron microscopy revealed that the addition of SEBS‐g‐MA was beneficial to the dispersion of PA 1212 in the PS matrix because of the reaction between them. The variation of the fraction of SEBS‐g‐MA in the blends allowed the manipulation of the phase structure, which first formed a sheetlike structure and then formed a cocontinuous phase containing PA 1212/SEBS‐g‐MA core–shell morphologies. As a result, the mechanical properties, especially the Charpy notched impact resistance, were significantly improved with the addition of SEBS‐g‐MA. Differential scanning calorimetry (DSC) data indicated that the strong interaction between SEBS‐g‐MA and PA 1212 in the blends retarded the crystallization of PA 1212. The heat distortion temperature of the compatibilized blends was improved in comparison with that of the unmodified blend, probably because of the apparent increase in the glass‐transition temperature with an increasing concentration of SEBS‐g‐MA. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1354–1360, 2005     

Toughening of recycled poly(ethylene terephthalate) with a maleic anhydride grafted SEBS triblock copolymer

Toughening of recycled poly(ethylene terephthalate) (PET) was carried out by blending with a maleic anhydride grafted styrene‐ethylene/butylene‐styrene triblock copolymer (SEBS‐g‐MA). With 30 wt % of the SEBS‐g‐MA, the notched Izod impact strength of the recycled PET was improved by more than 10‐fold. SEM micrographs indicated that cavitation occurred in just a small area near the notch root. Addition of 0.2 phr of a tetrafunctional epoxy monomer increased the recycled PET melt viscosity by chain extension reaction. Different from the positive effect of the epoxy monomer in toughening of nylon and PBT with elastomers, the use of the epoxy monomer in the recycled PET/SEBS‐g‐MA blends failed to further enhance dispersion quality and thus notched impact strength. This negative effect of the epoxy monomer was attributed to the faster reactivity of the epoxy group with maleic anhydride of the SEBS‐g‐MA than with the carboxyl or hydroxyl group of recycled PET. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1462–1472, 2004     

Toughening and compatibilization of polyphenylene sulfide/nylon 66 blends with SEBS and maleic anhydride grafted SEBS triblock copolymers

In this study, styrene‐b‐ethylene/butylene‐b‐styrene triblock copolymer (SEBS) and maleic anhydride grafted SEBS (SEBS‐g‐MA) were used as compatibilizers for the blends of polyphenylene sulfide/nylon 66 (PPS/PA66). The mechanical properties, including impact and tensile properties and morphology of the blends, were investigated by mechanical properties measurements and scanning electron microscopy. Impact measurements indicated that the impact strength of the blends increases slowly with elastomer (SEBS and SEBS‐g‐MA) content upto 20 wt %; thereafter, it increases sharply with increasing elastomer content. The impact energy of the elastomer‐compatibilized PPS/PA66 blends exceeded that of pure nylon 66, implying that the nylon 66 can be further toughened by the incorporation of brittle PPS minor phase in the presence of SEBS or SEBS‐g‐MA. The compatibilization efficiency of SEBS‐g‐MA for nylon‐rich PPS/PA66 was found to be higher than SEBS due to the in situ forming SEBS interphase between PPS and nylon 66. The correlation between the impact property and morphology of the SEBS‐g‐MA compatibilized PPS/PA66 blends is discussed. The excellent impact strength of the nylon‐rich blends resulted from shield yielding of the matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Effect of nylon 6 on fracture behavior and morphology of tough blends of poly(2, 6‐dimethyl‐1,4‐phenylene oxide) and maleated styrene‐ethylene‐butadiene‐styrene block copolymer

Ternary blends of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO), nylon 6, and styrene‐ethylene‐butadiene‐styrene block copolymer grafted with maleic anhydride (SEBS‐g‐MA) were prepared via a melt extrusion, and the fracture behavior, morphology, mechanical properties, and rheology were studied. The compatibilization of the blended components was confirmed by differential scanning calorimetry (DSC) analysis. Mechanical properties evaluation demonstrated that incorporation of nylon 6 resulted in an improvement of the tensile strength, but reduction of both the notched Izod impact strength and elongation at break. Transmission electron microscopy (TEM) observation revealed that the network structure of SEBS‐g‐MA domain was gradually destroyed by incorporating the nylon 6. A conversion of SEBS‐g‐MA domain from the network to the irregular dispersed phase took place when the nylon 6 content reached 20 wt %, which resulted in a reduction of the impact strength. Fracture morphology implied that increase of the tensile strength was caused by the plastic deformation of matrix. Rheology investigation indicated that the melt viscosities could be reduced significantly with increasing the content of nylon 6; thus, the processability was improved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3336–3343, 2006     

Modification of tensile and impact properties of poly(butylene terephthlate) by incorporation of styrene‐ethylene‐butylene‐styrene and maleic anhydride‐grafted‐SEBS (SEBS‐g‐MA) terpolymer

Tensile behavior and impact strength of poly(butylene terephthlate) (PBT)/styrene‐ethylene‐butylene‐styrene (SEBS) copolymer blends were studied at SEBS volume fraction 0–0.38. Tensile modulus and strength decreased, whereas breaking elongation increased with SEBS content. Predictive models are used to evaluate the tensile properties. Strength properties were dependent on the crystallinity of PBT and phase adhesion. The normalized notched Izod impact strength increased with the SEBS content; at Φ_d = 0.38, the impact strength enhanced to five times that of PBT. Scanning electron microscopy was used to examine phase morphology. Concentration and interparticle distance of the dispersed phase influenced impact toughening. In the presence of maleic anhydride‐grafted SEBS (SEBS‐g‐MAH), the tensile modulus and strength decreased significantly, while normalized relative notched Izod impact strength enhanced to 7.5 times because of enhanced interphase adhesion. POLYM. ENG. SCI., 53:2242–2253, 2013. © 2013 Society of Plastics Engineers