超韧尼龙11合金的力学性能和相态研究

研究了尼龙11和POE的共混物，制备了不同的马来酸酐接枝率的尼龙11／POE－g－MAH和尼龙11／POE／POE－g-MAH共混物，研究了共混物的力学性能和相态。结果表明，引入POE－g-MAH能够提高相容性和共混物的韧性，并且马来酸酐接枝率越高效果越为明显，与此同时，拉伸强度却降低得很少。     

增容剂对尼龙6／乙烯^=醋酸乙烯酯共聚物共混合金的亚微形态与力…

采用两种含有羟基官能团的共聚物作为增容剂，通过反应挤出法制备了尼龙６／乙烯－醋酸乙烯酯共聚物（ＥＶＡ）共混合金；并对合金的力学性能和亚微形态进行了研究，结果表明，通过挤出过程中增容剂的羧基宫能团与尼龙６反应，可提高尼龙６与ＥＶＡ的界面粘结性，从而使合金获得较高的缺口冲击强度，同时合金的断裂伸长率也显著提高，ＳＥＭ研究显示，ＥＶＡ与尼龙６的相容性较差，基体中ＥＶＡ粒子直径约为１．５－２．０ｕｍ；而添     

增容剂对尼龙6／乙烯~＝醋酸乙烯酯共聚物共混合金的亚微形态与力学性能的影响

采用两种含有羧基官能团的共聚物作为增容剂，通过反应挤出法制备了尼龙６／乙烯－醋酸乙烯酯共聚物（ＥＶＡ）共混合金；并对合金的力学性能和亚微形态进行了研究．结果表明，通过挤出过程中增容剂的羧基官能团与尼龙６反应，可提高尼龙６与ＥＶＡ的界面粘结性，从而使合金获得较高的缺口冲击强度，同时合金的断裂伸长率也显著提高ＳＥＭ研究显示，ＥＶＡ与尼龙６的相容性较差，基体中ＥＶＡ粒子直径约为１．５——２．０μｍ；而添加增容剂后，可以提高ＥＶＡ在基体中的分散性，并使分散相粒子的直径显著减小     

EVA-g-MAH对PA6/EVA共混合金原位反应增容作用的研究

用乙烯－醋酸乙烯酯共聚物（ＥＶＡ）对尼龙６（ＰＡ６）进行增韧,加入乙烯－醋酸乙烯酯共聚物与马来酸酐的接枝物（ＥＶＡ－ｇ－ＭＡＨ）进行原位反应增容,在反应型双螺杆挤出机上实现反应增容共混过程,制备出了具有超韧性的ＰＡ６／ＥＶＡ／ＥＶＡ－ｇ－ＭＡＨ三元共混合金。探讨了ＥＶＡ－ｇ－ＭＡＨ对ＰＡ６／ＥＶＡ的原位反应及增容机理,用倍高扫描电镜考察了合金材料的亚微相态。结果表明,ＥＶＡ－ｇ－ＭＡＨ的加入使合金     

HIPS-g-MA共聚物对HIPS/PC共混物相容性、形态和拉伸性能的影响

研究了HIPS／PC共混物的相容性及HIPS－MA对HIPS（30）／PC（70）共混物的相容性、形态和拉伸性能的影响。DSC研究结果表明，HIPS／PC共混物中PS的玻璃化转变温度（Tg)不随组成而变化，而PC的Tg随其质量分数的降低逐渐向低温移动，说明HIPS／PC是部分相容体系。通过DSC、扫描电镜形态观察和拉伸性能测试结果发现，当HIPS－g-MA的含量低于7．5％时，共混物的相容性改善不明显，当其含量达到7．5％时，对共混物有明显的乳化作用，说明饱和的界面浓度在7．5％左右。HIPS－g-MA接枝共聚物在HIPS（30）／PC（70）共混物中的增容作用可能是酯交换反应原位生成的嵌段共聚物所致。     

熔融法制备EPDM-g-GMA及其与PBT的共混增韧

研究了EPDM－g-GMA对PBT的增韧作用及其增韧机理，在XSS－300转矩流变仪上根据自由基聚合通过熔融反应制备了EPDM－g-GMA 及其PBT／EPDM－g-GMA，用傅立叶变换红外光谱法考察接枝反应中特征官能团的存在，根据红外工作曲线测定了改性样品的接枝率，获得了共混物的冲击强度，在扫描电子显微镜下观察了共混物断面的微观形态，实验结果表明，当接枝共聚物的接枝率为2．3，分散相粒径在0．5μm左右时，共混物的冲击强度可达49．7kJ/m^2，比纯PBT提高了30倍，接枝共聚物的存在可以改善EPDM与PBT间的相容性，EPDM对工程塑料PBT的增韧作用是通过提高两相间的界面结合，增强界面粘结作用实现的。     

马来酸酐化低分子量聚丁二烯接枝改性LLDPE的制备及增韧尼龙6的性能

在传统橡胶增韧塑料体系中,由于橡胶含量通常大于10%(质量分数,下同),不仅提高了材料的成本而且大幅降低了材料的强度和模量。文中报道了以马来酸酐化低分子量聚丁二烯(MLPB)接枝改性的线性低密度聚乙烯(LLD-PEg)为增韧剂,通过反应挤出的方法制备了LLDPEg与尼龙6(PA6)的合金。利用在反应挤出过程中LLDPEg增韧剂中马来酸酐(MAH)与PA6中端胺基的反应,在合金体系中形成以LLDPE为核,MLPB为壳的核-壳结构。结果发现体系中MLPB净含量只有3%时,核壳增韧体系的缺口冲击强度最高可达到118kJ/m2。与POE-g-MAH增韧PA6的体系相比,在相同增韧剂含量的情况下,核壳增韧体系的冲击强度和拉伸强度都更高。     

PA-6/ABS共混体系中加入SMA的反应型增容作用

加入少量苯乙烯－马来酸酐共聚物,能改善苯不相容的尼龙－６／ＡＢＳ共浊 系的相容性,提高其力学性能。文中共混物的熔体流变性能,ＤＳＣ表征及相结构观察,表明相容性的改善是在熔融共混过程中ＳＭＡ在ＰＡ－６和ＡＢＳ界面的的接枝反应得以实现。     

改性马来酸酐橡胶接枝物增韧尼龙6的制备及表征

为了促进橡胶接枝物与尼龙6(PA6)的相容性并提高增韧效果,利用马来酸酐和对苯二胺合成了一种含酰胺键的二元羧酸,命名为对苯马来二酰胺二酸(改性马来酸酐,MDMA),并将MDMA接枝到三元乙丙橡胶(EPDM)上,制备出不同接枝率的改性马来酸酐橡胶接枝物(EPDM-g-MDMA),以EPDM-g-MDMA与PA6质量比为30∶70,通过共混挤出制备了含不同接枝率接枝物的EPDM-g-MDMA/PA6共混物。通过核磁共振和红外光谱对MDMA进行了测试,表明成功合成了所需要的二元羧酸。对共混物进行了相容性测试、DSC、熔融指数(MI)、SEM、拉伸和冲击力学性能测试。结果表明:随着接枝率的增大,共混物的熔融峰温度略有降低,其熔体黏度不断增大,橡胶接枝物在PA6基体中有良好的分散性,使EPDM-g-MDMA/PA6共混物的冲击强度提高了5.5倍,说明EPDM-g-MDMA对PA6的增韧效果较为明显。     

EPDM-g-MAH对PPO/PA6共混体系结构与性能的影响

通过双螺杆熔融反应挤出,获得了马来酸酐化的三元乙丙橡胶(EPDM-g-MAH),并将其与聚苯醚(PPO)、尼龙6(PA 6)共混,制备了PPO/PA 6/EPDM三元共混合金。研究了弹性体EPDM-g-MAH中MAH用量以及EPDM-g-MAH用量对PPO/PA 6共混体系力学性能和相态结构的影响。结果表明:EPDM-g-MAH中MAH用量在1%~2%范围内,可显著改善EPDM与PPO/PA 6共混体系的相容性,大大提高共混合金的韧性;在三元共混体系中,随着弹性体EPDM-g-MAH用量的增加,冲击强度和断裂伸长率提高,但拉伸强度降低。     

Impact fracture behaviour of nylon 6-based ternary nanocomposites

This study focuses on achieving high stiffness/strength and high fracture toughness in nylon 6/organoclay nanocomposites prepared via melt compounding by incorporating a maleic anhydride grafted polyethylene–octene elastomer (POE-g-MA) as a toughening agent. Mechanical test results indicated that the ternary nanocomposites exhibited higher stiffness than nylon 6/POE-g-MA binary blends at any given POE-g-MA content. More importantly, the brittle–ductile transition of nylon 6/POE-g-MA blends was not impaired in the presence of organoclay for the compositions prepared in this study. TEM analysis shows that organoclay layers and elastomer particles were dispersed separately in nylon 6 matrix. In the binary nanocomposite, no noticeable plastic deformation was observed around the crack tip. In the ternary nanocomposites, the presence of organoclay in the matrix provided maximum reinforcement to the polymer, while their absence in the elastomer particles allowed the latter to promote high fracture toughness via particle cavitation and subsequent matrix shear yielding. The partially exfoliated clay layers also delaminated and hence, adding to the total toughness of the nanocomposites.     

极性可调高聚物接枝氧化石墨烯相容剂的制备及在MC尼龙中的应用

设计制备了极性可调控的反应型相容剂乙烯-辛烯共聚物-甲醛缩多乙烯多胺-g-氧化石墨烯(POE-TEPAF-GO),并将其应用于铸型尼龙(MC尼龙)/马来酸酐接枝乙烯-辛烯共聚物(MAPOE)共混体系中。同时,调节TEPAF相对分子质量大小,考察不同极性的相容剂对共混材料MC尼龙/MAPOE的影响。研究结果表明,POE-TEPAF-GO对MC尼龙/MAPOE共混体系增容效果较为理想,并且可作为多功能填料对共混材料实现增韧和增强,其中共混材料韧性提高最为显著,较纯MC尼龙提高93%,拉伸强度、热稳定性也有所改善,此外在一定程度上改变了晶型。当TEPAF的Mw=931时,材料的综合性能最优。     

POE-g-MAH反应性增容HDPE/PA6共混合金的热致形状记忆性能

采用乙烯-辛烯共聚物接枝马来酸酐(POE-g-MAH)作为高密度聚乙烯(HDPE)/尼龙6(PA6)共混体系的反应性增容剂,通过熔融挤出制备出固定相具有物理交联结构的热致形状记忆合金。研究了组分含量,拉伸比和形变回复温度对合金的形变回复率和回复速率的影响。结果表明,POE-g-MAH的添加显著提高了共混合金的形状记忆性能,当组分配比为80/20/10(HDPE/PA6/POE-g-MAH),形变回复温度为135℃,拉伸比为75%时,试样形变回复率达到96.5%。     

Morphological, mechanical and rheological properties of nylon 6/acrylonitrile-butadiene- styrene blends compatibilized with MMA/MA copolymers

The morphological, mechanical and rheological properties of nylon 6/acrylonitrile- butadiene-styrene blends compatibilized with MMA-MA [poly(methyl methacrylate-co- maleic anhydride)] copolymers were studied. A twin screw extruder was used for melt-blended the polymers and the injection moulding process was used to mold the samples. The main focus was on nylon 6/ABS blends compatibilized with one MMA-MA copolymer. This copolymer has PMMA segments that appear to be miscible with the styrene-acrylonitrile (SAN) phase of ABS and the anhydride groups can react with amine end groups of the nylon 6 (Ny6) to form graft copolymers at the interface between Ny6 and ABS rich phases. Tensile and impact and morphological properties were enhanced by the incorporation of this copolymer. Transmission electron microscopy (TEM) observations revealed that the ABS domains are finely dispersed in nylon 6 matrix and led to the lowest ductile-brittle transition temperatures and highest impact properties. It can be concluded that the MMA-MA copolymer is an efficient alternative for the reactive compatibilization and can be used as a compatibilizer for nylon 6/ABS blends.     

尼龙—6／PP—g—MAH共混体系的结构及流变行为

本文通过Ｍｏｌａｕ实验，二甲苯萃取抽出物的ＩＲ分析，ＤＳＣ，ＳＥＭ测定了尼龙－６／ＰＰ－ｇ－ＭＡＨ的结构，发现尼龙－６与ＰＰ－ｇ－ＭＡＨ的酸酐或羧酸发生了化学反应，生成的接枝共聚物起到了共混体系增容剂的作用，改善了共混物的微观结构形态。流变学测定表明，体系假塑性增加，熔体粘度上升，共混物的成型加工性能较之纯尼龙有所改善。     

CSW/POE-g-MA/PA6三元复合材料的结构和性能

采用马来酸酐接枝乙烯一辛烯共聚物(POE-g-MA)对CaS04晶须/尼龙6(CSW/PA6)共混物增韧改性,研究了csw/PA6和CSW/POE-g-MA/PA6复合材料的力学性能、热性能、形貌和加工性能.适量添加CSW可同时提高PA6的刚性和韧性.与纯PA6性能比较,10％CSW/PA6的拉伸强度、弯曲强度、弯曲模量和冲击强度分别增大7.5％、9.1％、21.1％和11.6％;当CSW含量增至30％,CSW/PA6的韧性明显降低.POE-g_MA可促进PA6基体中csw的均匀分散,增强CSW与PA6的界面粘附,提高CSW/PA6 (30/70)的冲击韧性.源于CSW和POE-g-MA的协同作用,CSW/POE-g-MA/PA6 (30/5/65)的冲击强度和弯曲模量与纯PA6相比较,分别提高了36.8％和22.1％,拉伸和弯曲强度接近纯PA6.     

Natural silica fiber as reinforcing filler of nylon 6

Short silica fiber (SF) content on the mechanical and morphological properties of composites based on nylon 6 and rubber-toughened nylon 6 matrices was examined. Binary nylon 6/SF and ternary [nylon 6/EPDM-g-MA (ethylene–propylene–diene grafted with maleic anhydride)/SF] composites containing 0–20 wt% SF were formulated. The flexural modulus increased with the SF content at all fiber compositions investigated; however, the value of this property gradually diminished when 20 wt% rubber was added to the polymer. Notched Izod impact strength of 80/20 nylon 6/EPDM-g-MA blend was reduced up to 50% with the addition of 5 wt% SF. However, these composites still retained good stiffness and toughness and presented a good interfacial adhesion between the phases. The results suggest that silica fibers can be employed as an alternative reinforcement of nylon 6 matrices, resulting in materials with useful properties.     

Thermal properties of nylon6/ABS polymer blends: Compatibilizer effect

Nylon6/ABS binary blends are incompatible and need to be compatibilized to achieve better performance under impact tests. Poly(methyl methacrylate/maleic anhydride) (MMA-MA) is used in this work to compatibilize in situ nylon6/ABS immiscible blends. The MA functional groups, from MMA-MA copolymers, react with NH₂ groups giving as products nylon molecules grafted to MMA-MA molecules. Those molecular species locate in the nylon6/ABS blend interfacial region increasing the local adhesion. MMA-MA segments are completely miscible with the SAN rich phase from the ABS. The aim of this work is to study the effects of ABS and compatibilizing agent on the melting and crystallization of nylon6/ABS blends. This effect has been investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). Incorporation of this compatibilizer and ABS showed little effect on the melting behavior of the PA6 crystalline phase, in general. DMTA analysis confirmed the system immiscibility and showed evidence of compatibility between the two phases, nylon6 and ABS, produced by MMA-MA copolymer presence. The nylon6/ABS blend morphology, observed by transmission electron microscopy (TEM), changes significantly by the addition of the MMA-MA compatibilizer. A better dispersion of ABS in the nylon6 phase is observed.