PA6/NMA共混物的制备及其性能研究

以聚酰胺6(PA6)为基体、自制N-苯基马来酰亚胺-马来酸酐二元共聚物(NMA)为耐热改性剂,通过熔融共混法制备了PA6//NMA共混材料。并采用差示扫描量热法(DSC)、热重分析(TGA)、热变形温度及力学性能测试等手段研究了NMA用量对PA6/NMA共混物熔融结晶行为、热性能及力学性能的影响。结果表明:随着NMA用量的增加,PA6/NMA共混物的熔融温度、结晶温度、结晶度以及熔融焓均逐渐降低,而且共混物的最大分解温度较纯PA6显著提高;随着NMA用量的增加,PA6/NMA共混物的力学性能及热性能均明显改善,其中当NMA用量为10份时,共混物的弯曲强度、弯曲模量、拉伸强度及热变形温度分别增至113.8 MPa、3 146 MPa、80.4 MPa以及71.5℃,较纯PA6提高了25.1%、31.9%、15.7%和27.5%;另外,随着NMA用量的增加,共混物的熔体流动速率(MFR)大幅下降,其中当NMA用量增至10份时,共混物的MFR降至5.3 g/10min。     

PA6/SMA共混物的热性能及力学性能

采用熔融共挤制备了尼龙6(PA6)/苯乙烯-马来酸酐共聚物(SMA)共混物,利用差示扫描量热法、热重分析、热变形温度测试及力学测试等手段研究了SMA含量对PA6/SMA共混物熔融结晶行为、热性能及力学性能的影响。结果表明,SMA的加入使共混物的熔融温度、结晶温度及结晶度降低;当SMA用量为5份时,共混物最大分解温度较纯PA6提高了33.5℃;共混物的弯曲强度和弯曲模量在SMA用量为2.5份时达到最大,分别为115.0、3 227 MPa,比纯PA6提高了26.4%、37.0%,拉伸强度在SMA用量为5份时达到最大87.5 MPa,比纯PA6提高了25.9%。     

PA6/SMA/LGF复合材料的制备及其性能研究

采用熔融共混法制备了聚酰胺6/苯乙烯-马来酸酐共聚物/长玻璃纤维(PA6/SMA/LGF)复合材料,利用差示扫描量热法(DSC)、热重分析(TGA)、热变形温度及力学性能测试等手段研究了LGF含量对PA6/SMA/LGF复合材料熔融结晶行为、热性能及力学性能的影响。结果表明:随着LGF含量的增加,PA6/SMA/LGF复合材料的结晶温度、结晶度以及熔融焓均先升高再降低,而且复合材料的最大分解温度较纯PA6显著提高;另外,随着LGF含量的增加,PA6/SMA/LGF复合材料的热性能及力学性能均明显改善,其中当LGF含量为27%时,复合材料的热变形温度、弯曲强度、弯曲模量、拉伸强度和冲击强度分别增至206.0℃、227.8 MPa、7 335 MPa、180.6 MPa和18.7 kJ/m2。     

聚酰胺6-聚醚胺弹性体的制备及其共混改性研究

以己内酰胺、聚醚胺为原料，采用一步法制备聚酰胺6-聚醚胺(TPAE)弹性体，并将该弹性体与聚酰胺6(PA 6)进行熔融共混制备PA 6/TPAE共混料，研究了TPAE弹性体含量对PA 6结晶性能、熔体流动性能及力学性能的影响。结果表明：制备的TPAE弹性体断裂伸长率为703.45%,常温冲击不断，热失重5%时的温度为341.3℃,具有弹性体高韧性的特征和较好的热稳定性，在高温高剪切作用下适合与PA 6共混；当共混添加质量分数为2.5%的TPAE弹性体时，PA 6/TPAE共混料的结晶度为23.07%,共混熔体压力为2.60 MPa,每10 min熔体流动速率为11.06 g,优于经螺杆剪切的PA 6,拉伸强度和弯曲强度分别为75.31,105.11 MPa,达到未经螺杆剪切的PA 6的强度，弥补了PA 6经高温剪切后的力学性能损失。     

液体冷却温度对PP/PP-g-马来酸酐/PA6共混单丝结构与性能的影响

采用一定比例的聚己内酰胺(PA6)及增容剂对聚丙烯(PP)进行共混改性,纺制大直径单丝。通过对共混单丝的力学性能、扫描电子显微镜及热性能测试分析,研究了液体冷却成形温度对共混单丝拉伸强度、勾结强度的影响。结果表明:液体冷却温度对PP/PP-g-MAH/PA6共混单丝的力学性能具有很大的影响。随着液体冷却温度的下降,共混纤维的拉伸强度及勾结强度都得到不同程度的提高。     

PA6/NMA/EP共混物的热性能及其力学性能研究

采用熔融共混法制备PA6/NMA/EP共混物;利用差示扫描量热法(DSC)、热重分析(TGA)、热变形温度测试仪、微机控制电子万能试验机等对其性能进行测试,并研究了EP与PA6的质量比对PA6/NMA/EP共混物的结晶行为、热性能及力学性能的影响。结果表明:随着EP与PA6的质量比的增加,PA6/NMA/EP共混物的结晶度先减小后增加,但热稳定性呈现先增加后减小的趋势;当EP与PA的质量比为2%时,PA6/NMA/EP共混物的热变形温度和拉伸强度均达到最大值72.8℃和77.7 MPa,分别较纯PA6的提高了37.6%和11.8%;而弯曲强度随EP与PA6的质量比的增加呈现逐渐增大的趋势。     

超支化聚合物对PA6及其纤维性能的影响

将聚己内酰胺(PA6)与超支化聚合物(HBP)共混造粒、纺丝,研究了PA6/HBP共混物的流变性能及共混纤维的力学性能。结果表明:PA6/HBP共混物为非牛顿性假塑性流体,其表观黏度随着剪切速率的增大而减小;随着HBP含量增大,共混物非牛顿流动指数降低,剪切速率上升,加工温度降低;共混物黏流活化能随着HBP含量的增大而增大;PA6/HBP共混物较PA6结晶度提高,球晶明显细化;当w(HBP)为1.0%时,PA6/HBP共混纤维的断裂强度较纯PA6纤维略有降低,随着HBP含量的增加,共混纤维的力学性能明显降低。     

PA6/SMA/N-PMI复合材料的热性能和力学性能研究

采用熔融共混法制备了聚酰胺6/苯乙烯-马来酸酐共聚物/N-苯基马来酰亚胺复合材料(PA6/SMA/N-PMI),利用差示扫描量热法(DSC)、热重分析(TGA)及力学性能测试等手段研究了N-PMI用量对PA6/SMA/N-PMI复合材料熔融结晶行为、热性能以及力学性能的影响。结果表明:复合材料的最大分解温度较纯PA6有所提高;随着N-PMI用量的增加,复合材料的结晶温度、结晶度以及熔融焓均逐渐降低;当N-PMI用量为15份时,复合材料的弯曲强度、弯曲模量、拉伸强度以及热变形温度均达到最大值,分别为101.0、2 892、71.6 MPa以及56.6℃,较纯PA6分别提高了11.0%、21.3%、3.1%和10.0%。     

纳米复合金属氧化物/聚酰胺6复合纤维的制备及性能

用共沉淀法制备了锌铝、锌镁铝及镁铝层状双氢氧化物(LDHs),将LDHs经过500℃煅烧后,得到相应的纳米复合金属氧化物(MMO)。MMO经偶联剂表面改性后,与聚酰胺6(PA6)切片共混造粒、熔融纺丝制备MMO/PA6复合纤维,并织造了MMO/PA6织物。用差示扫描量热仪(DSC)、扫描电子显微镜(SEM)以及红外成像仪等研究了MMO/PA6复合纤维的热性能、横截面形貌及MMO/PA6织物的红外辐射性能。结果表明:MMO/PA6复合纤维的可纺性好;加入MMO后,PA6复合纤维的强度下降约10%,但对PA6纤维的熔融温度没有影响;MMO的加入显著提高了PA6纤维的红外辐射性能,60℃保温的MMO/PA6织物,当MMO的质量分数为2.0%时,其温度高于空白PA6织物约2.0℃,具有优异的远红外辐射性能。     

纳米OMMT对PA6/PET共混体系结晶性能的影响

采用熔融共混法,以PA6/PET(30/70)和PA6/PET(70/30)合金为研究对象,利用差示扫描量热法(DSC)探讨纳米有机OMMT对PA6/PET共混物结晶性能的影响,结果表明:PA6/PET共混物中,PA6相和PET相均能各自结晶,且PA6相阻碍PET相的结晶,而PET相对PA6相的结晶性能没有影响。引入纳米OMMT后,体系中PA6相和PET相的结晶温度均降低,并缩短半结晶时间,加剧两组分结晶温度对降温速率的依赖性。用莫志深方法处理纯PA6/PET共混物和PA6/PET/OMMT纳米复合材料的非等温结晶动力学,结果表明:在PA6/PET(30/70)共混体系中引入纳米OMMT后,F(T)值均增大,而在PA6/PET(70/30)共混体系中引入纳米OMMT,F(T)值减小。     

Fibers spun from blends of different molecular weights of polypropylene

Fibers spun from blends of small percentage of plastic grade polypropylene (HMPP) with fiber grade polypropylene (PP) are studied for drawing behavior. A factorial design of experiment is used for a two-stage drawing process with variables, such as percent of HMPP component, first stage draw ratio and temperature, and second stage temperature. Optimization is carried out for breaking stress and modulus of drawn filaments. Breaking stress of up to 0.74 GPa and initial modulus of 7.34 GPa is possible by such an optimization process. These properties are observed for 6% HMPP blend composition. Heat setting of drawn filaments show little changes up to 140°C heat-setting temperature. Large scale structural changes with rapid drop in mechanical properties is observed for 150-160°C heat-set samples.     

Correlation between creep and dyeability of fibers

The dye uptake and creep deformation of commercial and heat-set poly(ethylene terephthalate) and nylon 6 fibers have been studied. On heat-setting, both dye uptake and creep are seen to decrease in the case of PET but show an increase in the case of nylon 6 fibers. This indicates that the rate-controlling factor for both these processes may be the same, and it is suggested that this factor could be sample morphology, in particular, the size and distribution of the amorphous volume in the fiber.     

Investigation on the multiwalled carbon nanotubes reinforced polyamide 6/polypropylene composites

Multiwalled carbon nanotubes (MWNTs) reinforced polyamide 6/polypropylene (PA6/PP = 70/30) composites were prepared by melt compounding. Maleated polypropylene (MPP) was used as a compatibilizer for the composites. The morphology, mechanical properties, thermal stability, rheological properties and crystallization behavior of the composites were investigated. It was found that the addition of MWNTs to PA6/PP blend resulted in decrease in the size of the dispersed particles. Most of MWNTs were selectively dispersed in the PA6 phase and a small amount of MWNTs were located in the interphase between PA6 matrix and PP phase as characterized by scanning electric microscopy. The strength and stiffness of the PA6/PP blend were greatly improved by the addition of MWNTs. The MPP and MWNTs had a synergistic effect on the improvement ofthe thermal stability. In addition, the complex viscosity, storage modulus and loss modulus of the composites increased with the addition of MWNTs or MPP. MWNTs could induce the formation of α crystalline form of PA6. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Heat setting of stretched and microvoided PE/CaCO3 films

Calcium-carbonate-filled linear low-density polyethylene (LLDPE) films play an important role in the hygienics market because these materials allow for the diffusion of water vapor (breathability) and retain a liquid barrier while providing a barrier to liquids. This is achieved when properly formulated composites are stretched to create pores. There are many important issues surrounding this technology; this report focuses on the effects of poststretching heat-set treatment on moisture vapor transmission rate (MVTR), dynamical mechanical thermal analysis (DMTA), tensile heat distortion temperature (THDT), and differential scanning calorimetry (DSC) thermal transitions of the porous film properties. Eastman personnel provided the LLDPE/CaCO₃ breathable films for this study. In general, the film properties were insensitive to heat-setting time beyond that of 1 min. This result suggests that the molecular reorientation and recrystallization associated with the changes in film properties occur rapidly. Properties were, however, strongly sensitive to the heat-set temperature when MVTR decreased and DMTA properties [specifically storage modulus (E′) and the α-transition temperature] increased as the heat-set temperature increased. This is believed to have been mainly caused by pore closure and the annealing of crystalline regions. The heat-set temperature was easily detectable by DSC techniques when a thermal transition was apparent at the applied temperature, and changes in the heat of fusion for the sample could be observed. Ultimately, the changes in the properties of these porous films were related to changes in the molecular orientation and crystallinity of the matrix in combination with changes in the void structure of the composite. In particular, changes in E′ could be related to these separate effects. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2454–2471, 2001     

PES/PA6的共混纺丝及其性能研究

将不同质量比的聚醚砜(PES)与聚酰胺6(PA6)共混进行熔融纺丝制得PES/PA6共混纤维;研究了共混物的流动性及其纺丝工艺,以及PES/PA6共混纤维的热稳定性和力学性能。结果表明:PA6的加入显著提高了PES的流动性,降低了纺丝温度,改善了PES的可纺性;与纯PES纤维相比,PES/PA6共混纤维的起始热分解温度有所降低,PES/PA6质量比为70/30～30/70的PES/PA6共混物的纺丝温度为320～340℃,卷绕速度为100～400 m/min,纤维的断裂强度为0.71～2.25 cN/dtex。     

Preparation and properties of novel epoxy composites containing electrospun PA6/F‐MWNTs fibers

The Nylon 6 (PA6)/the functionalized multiwalled carbon nanotubes (F‐MWNTs) fibrous membranes were fabricated by electrospinning, and then incorporated into an epoxy matrix. Their morphology, thermal stability, mechanical properties, thermal conductivities, and electrical resistivity were investigated. The electrospun PA6/F‐MWNTs fibers performed as a skeleton in the epoxy matrix, and the well interfacial adhesion between the epoxy matrix and the PA6/F‐MWNTs fibers leads to high mechanical properties of composites. The PA6 serves as an intermediate layer and alleviates the modulus mismatch between the stiff MWNTs and the soft epoxy matrix. The thermal conductivities of the epoxy composites increase by 27.3, 35.0, and 36.1%, respectively, with 0.5, 1 and 1.5 wt% F‐MWNTs loading in the PA6/F‐MWNTs fibers. At the same time, the PA6 simultaneously retains the high electrical resistivity of these epoxy composites. POLYM. ENG. SCI., 56:1259–1266, 2016. © 2016 Society of Plastics Engineers     

生物可降解PBST共聚酯FDY的工艺探讨

介绍了运用热辊纺牵一步法纺制聚丁二酸-共-对苯二甲酸丁二醇酯(PBST)全拉伸丝的工艺。采用干燥温度110℃,纺丝温度257℃,侧吹风温度25℃,拉伸倍数1.8倍,定型温度120℃,可生产出具有良好物理机械性能的PBST FDY。     

热定型温度对芳纶Ⅲ结构与性能的影响

研究了不同热定型温度对芳纶Ⅲ的力学性能、结晶度、取向度及热性能的影响。结果表明:随着热处理温度的提高,芳纶Ⅲ弹性模量增大,而拉伸强度和断裂伸长率则增大到峰值后开始逐步下降;纤维结晶度随温度升高而增大;纤维取向度在经过热定型后有小幅度提高;不同热定型处理温度下,纤维的热分解温度均为533℃,分解速率差别较小。     

呋喃/环氧/胺类固化剂共混体系的固化反应机理及性能研究

采用溶液法制备了呋喃/环氧树脂/胺类固化剂的共混物。采用粘度测试仪、DSC、FT-IR、力学测试仪、SEM对共混体系的加工性、固化反应机理及固化后样品的力学性能及机理进行了研究。研究结果揭示了共混体系的固化反应机理,发现在共混体系中呋喃树脂与部分环氧树脂可以在180℃附近反应,剩余部分环氧树脂需要在更高的温度下才能进一步完全反应。共混体系具有优异的力学性能,且随着共混体系中环氧树脂含量的增多在逐渐升高,其中弯曲强度最高达到113 MPa,弯曲模量最高达到4129 MPa,冲击强度最高达到19.1kJ/m~2。对冲击断口形貌进行观察,发现共混体系浇铸体具有相分离结构是性能优异的主要原因。     

后处理对PLLA/PDLA共混纤维结构和性能的影响

采用聚L-乳酸(PLLA)与聚D-乳酸(PDLA)共混熔融纺丝,初步研究了后处理条件对纤维结构与性能的影响。结果表明:通过PDLA与PLLA的共混熔融纺丝,形成了立体复合型PLA晶体(sc-PLA);随着热处理温度的提高,纤维中sc-PLA晶体的含量增加,纤维力学性能下降;拉伸温度为75℃时所得纤维的力学性能最好,随着拉伸倍数的增加,纤维力学性能提高,纤维中sc-PLA晶体的含量变化不大。