PET/蒙脱土纳米复合材料的增韧研究

以聚对苯二甲酸乙二酯(PET)为基体,以(甲基丙烯酸甲酯／丙烯腈／丁二烯／苯乙烯)共聚物为增韧剂,采用熔融共混法制备了PET／蒙脱土纳米复合材料。用广角X射线衍射仪、透射电子显微镜研究了复合材料的微观结构,并测试了力学性能。结果表明,所制得的纳米复合材料具有剥离型和插层型结构;增韧剂及增容剂的引入都较大程度地提高了复合材料的缺口冲击强度,而拉伸强度和弯曲强度基本不变;纳米蒙脱土及增容剂的加入提高了纳米复合材料结晶性能。     

PET石墨烯复合材料的制备及性能研究

将氧化石墨烯(GO)与精对苯二甲酸(PET)、乙二醇(EG)进行原位聚合,制备了氧化石墨烯/PET(GO/PET)复合材料,研究了氧化石墨烯对PET聚酯的热性能、结晶性能的影响,并制备复合材料纤维,测试了其力学性能.结果表明:GO的加入提高了PET的热稳定性、结晶温度及结晶速率但没有改变PET的成核方式和生长方式.与纯PET相比,加入GO后纤维的拉伸强度降低,断裂伸长率提高,但与低GO含量的PET纤维相比,GO含量较高的PET纤维的拉伸强度更高.     

成膜剂和剪切场对GF/PET结构与性能影响

采用不同的成膜剂处理玻纤(GF),改变制备试样过程中熔体流动场剪切速率来挤出制备了GF/聚对苯二甲酸乙二醇酯(PET)复合材料。通过测定PET及GF/PET复合材料试样流变性能和纵向拉伸强度,研究成膜剂和熔体剪切速率对GF/PET复合材料结构和性能的影响。结果表明,聚合物成膜剂与硅烷偶联剂并用处理GF,能提高GF/PET复合材料的力学性能,低相对分子质量PET成膜剂处理后的GF与PET的粘结性很好;在熔融成型GF/PET复合材料试样过程中,剪切速率影响GF在复合材料中取向,试样力学强度对应有最佳的熔体流动场剪切速率。     

短切玻璃纤维(GF)增强PET复合材料的研究

通过溶液法制备了短切玻璃纤维增强PET复合材料；研究了短切玻璃纤维含量和长度对PET／GF复合材料强度的影响；并对试样冲击断口的显微结构和断裂形态进行了分析。结果表明，复合材料的强度随玻璃纤维含量的增加先提高后降低，即出现极值，随玻璃纤维长度的增加其强度略有提高；且要制得玻璃纤维分布均匀的PET／GF复合材料；KH550是PET／GF复合体系的良好偶联剂。     

β成核剂和PET纤维对PP力学性能的影响

为提升聚丙烯(PP)韧性同时保持较大的刚性,以PP为基体,通过添加β-成核剂、PET纤维以及PP-gMAH制备复合材料,并研究复合材料的晶型结构及力学性能。结果表明:PP主要形成α-晶,加入β-成核剂则主要形成β-晶,且具有较大的冲击强度。加入PET纤维,可提高PP和β-PP的拉伸性能,随着PET纤维的增加,复合材料的拉伸强度逐渐提高,但冲击强度和断裂伸长率明显下降。相对而言,β-PP复合材料的冲击强度是PP复合材料的2倍,同时能保持较大的拉伸强度和弹性模量。经PP-g-MAH增容,可同时提高PP和β-PP复合材料的拉伸强度和冲击强度。因此,可在PP中添加β-成核、PET纤维和PP-g-MAH制备高强高韧的复合材料。     

具有"沙袋"结构的PP/EPDM/CB导电复合材料的增韧机理研究

研究了含"沙袋"结构的聚丙烯(PP)/(乙烯/丙烯/二烯)共聚物(EPDM)/炭黑(CB)三元导电复合材料的增韧机理.结果表明,含"沙袋"结构的导电复合材料体积电导率和缺口冲击强度同步增长的原因在于其特殊的增韧方式,在外力冲击过程中,PP基体受CB粒子的拉伸成纤以及纤维的伸长与断裂是这种特殊三元导电复合材料吸收冲击能量的主要手段之一.     

PET/纳米硫酸钡复合材料性能研究

通过熔融共混法制备聚对苯二甲酸乙二酯(PET)/纳米BaSO4复合材料,研究了纳米BaSO4对PET结晶行为、力学性能及热性能的影响。结果表明,纳米BaSO4在PET基体中起到了成核剂的作用,明显提高了基体树脂的结晶温度和结晶速率,并使材料的DSC曲线发生了显著变化;纳米BaSO4对PET有明显的增强作用,当其质量分数为2%时,PET/纳米BaSO4复合材料的力学性能最优,对比纯PET试样,其拉伸强度和弯曲强度分别提高了16%和18.6%,拉伸弹性模量和弯曲弹性模量分别提高了32%和14%,缺口冲击强度稍有下降;纳米BaSO4也可提高PET的热变形温度。     

利用原位纳纤和长支链聚丙烯协同作用制备高熔体聚丙烯

采用挤出-拉伸-热处理成型工艺制备了聚丙烯/聚对苯二甲酸乙二醇酯(PP/PET)原位成纤复合材料,以提高PP的熔体强度。研究了PET纳米级纤维对复合材料的熔体强度、流变性能和发泡性能的影响,结果显示材料的熔体强度从9 889 kPa·s提高到55 215 kPa·s。进一步通过在PP/PET复合材料中添加长支链聚丙烯(LCBPP,熔体强度22 453 kPa·s)使材料的熔体强度提高到80 769 kPa·s,可见LCBPP与原位纳纤对提高PP的熔体具有协同作用。流变数据显示PET纳纤的引入使复合材料的储能模量和复数黏度显著升高,这是因为PET纳纤能够增加熔体的缠结程度,从而使其熔体强度得到提高。最后从模压发泡性能上也证明了PP熔体强度的提高,这也说明此方法可用于工业发泡领域以提高低熔体强度材料的发泡性能。     

原位制备GO/PET复合材料的结构与性能

采用溶剂置换法制备了分散均匀的氧化石墨烯(GO)/乙二醇(EG)溶液,进而通过原位聚合法制备了氧化石墨烯/聚对苯二甲酸乙二醇酯(GO/PET)复合材料,探讨了溶剂置换法对GO在溶剂中分散性能的影响,并研究了GO含量对PET基复合材料结构与性能的影响。结果表明,通过溶剂置换法预处理,再经原位聚合制备的GO/PET复合材料中的GO分散均匀,无明显团聚现象。随着GO含量的增加,复合材料的熔融温度和拉伸强度明显降低,但结晶温度与弹性模量明显提高。当GO含量为0. 01%时,拉伸强度最大,为52. 9 MPa,与纯PET相比,提高了12%;当GO含量为0. 5%时,弹性模量最大,为2 297. 2 MPa,比纯PET相比提高了16%。     

PET/n-SiO2复合材料力学和流变性能的实验研究

将纳米级二氧化硅和PET均匀混合制造复合材料,用万能电子拉力机对PET/n-SiO2复合材料的力学性能进行了测试。测试结果表明适当加入纳米二氧化硅,复合材料拉伸强度有明显提高,且纳米二氧化硅添加量在2.0 wt%时力学性能最佳。利用德国BRUKER公司的TENSOR27型傅立叶变换红外光谱仪(FTIR)对复合材料的结构进行分析。结果表明PET在成型过程中没有发生氧化或其它化学变化。利用转矩流变仪对复合材料的流变性能进行测试,测试结果表明其加工性能良好。     

双转子连续混炼机中PP/PET原位复合共混的研究

利用双转子连续混炼机进行了聚丙烯/聚对苯二甲酸乙二醇酷(PP/PET)原位共混实验。通过分析共混物的微观形貌,探讨了流变行为对PET原位复合材料形成微纤的影响,以及共混温度、组分含量、剪切速率等对微纤形成的作用,并研究了组分相容性与成纤的关系,最后,探讨了PET组分含量对材料拉伸强度的影响及其作用机制。研究结果表明,在双转子连续混炼机中通过控制各加工参数,PET分散相在PP基体中可以获得显著成纤,并有利于提高复合材料的拉伸性能。     

Surlyn对PET及其共混体系流变与结晶性能的影响

通过熔融共混法制备了聚对苯二甲酸乙二醇酯 (PET)/聚酰胺6 (PA6)/Surlyn与PET/均苯四甲酸酐 (PMDA)/Surlyn共混材料,研究了Surlyn对共混体系的形貌以及共混体系中PET流变性能与结晶性能的影响。并使用扫描电子显微镜 观察了PET/PA6/Surlyn共混物的低温淬断断面,使用旋转流变仪与差示扫描量热仪研究共混物的流变性能与结晶性能。结果表明,Surlyn可以提高PET/PA6/Surlyn共混体系的熔体强度,促进共混体系中PET的结晶,使PET结晶温度提高10 ℃,过冷度与结晶半高宽显著下降,明显改善PET的流变性能与结晶性能,而对于PMDA扩链后的PET,Surlyn对其结晶性能的影响影响较小;Surlyn可以降低PA6分散相的粒径,提高PET与PA6两相之间的相容性。     

Morphological,mechanical, and physical properties of composites made with wood flour‐reinforced polypropylene/recycled poly(ethylene terephthalate) blends

Wood flour (WF)‐filled composites based on a polypropylene (PP)/recycled polyethylene terephthalate (r‐PET) matrix were prepared using two‐step extrusion. Maleic anhydride grafted polypropylene (MAPP) was added to improve the compatibility between polymer matrices and WF. The effects of filler and MAPP compatibilization on the water absorption, mechanical properties, and morphological features of PP/r‐PET/WF composites were investigated. The addition of MAPP significantly improved mechanical properties such as tensile strength, flexural strength, tensile modulus, and flexural modulus compared with uncompatibilized composites, but decreased elongation at break. Scanning electron microscopic images of fracture surface specimens revealed better interfacial interaction between WF and polymer matrix for MAPP‐compatibilized PP/r‐PET/WF composites. MAPP‐compatibilized PP/r‐PET/WF composites also showed reduced water absorption due to improved interfacial bonding, which limited the amount of absorbable water molecules. These results indicated that MAPP acts as an effective compatibilizer in PP/r‐PET/WF composites. POLYM. COMPOS., 38:1749–1755, 2017. © 2015 Society of Plastics Engineers     

纳米CaCO3对PET／M-POE体系力学性能的影响

采用马来酸酐接枝乙烯-辛烯共聚弹性体(M-POE)和纳米CaCO3协同增韧聚对苯二甲酸乙二酯(PET)。结合复合材料的室温缺口冲击断面扫描电镜照片、淬断刻蚀照片和宏观力学性能,分析了复合体系发生脆-韧转变对应的微观形貌特征。结果表明,直接将M-POE、纳米CaCO3与PET熔融共混并不能起到协同增韧效果,随着纳米CaCO3含量的增加,三元复合体系的缺口冲击强度逐渐降低。纳米CaCO3经过不同表面处理后,在复合体系中的微观分布不同,从而导致体系力学性能变化。不同的加工工艺可以制得纳米CaCO3分布不同的复合材料。研究发现,纳米CaCO3分布于PET基体中会引起复合材料冲击强度的下降。而纳米CaCO3分布于弹性体中,即形成所谓的“沙袋结构”,不仅可以明显提高复合材料的冲击强度,还可降低橡胶用量。     

Effect of short polyethylene terephthalate fibers on properties of ethylene-propylene diene rubber composites

The alteration in some properties of electron beam (EB) cured ethylene-propylene diene rubber (EPDM) reinforced by polyethylene terephthalate (PET) fiber was investigated in this study. Bonding system Resorcinol/Hexamethylenetetramine/Silica (RHS) was used to enhance the fiber/EPDM adhesion and to maintain optimum composite strength properties. Mechanical properties of composites namely; tensile strength, hardness and modulus at 100 % elongation have been enhanced by adding PET fibers and increasing irradiation dose. Moreover, the effect of fiber loading and irradiation dose on the soluble fraction behavior of the composite in benzene was also investigated. The soluble fraction of the composites decreased with increasing the fiber loading and irradiation dose. The extent of fiber alignment and strength of fiber-rubber interface adhesion were analyzed from the anisotropic swelling measurements. In addition, thermal stability of the composites was increased. Besides, the mechanical properties like tensile strength and stiffness were improved by thermal ageing. Scanning electron microscopy (SEM) for the fractured surfaces and Wide- angle X- ray diffraction (WAXD) of the investigated samples confirmed that the adhesion occurred between fibers and EPDM.     

Preparation and properties of poly(ethylene terephthalate)/inorganic whiskers composites

To improve the crystallization and mechanical properties of poly(ethylene terephthalate) (PET), in this work, PET/SiO₂‐MgO‐CaO whiskers composites were prepared via in situ polymerization. The morphology, crystallization, and mechanical properties of the prepared composites were investigated. It was found that inorganic whiskers could be easily dispersed in PET matrix, as demonstrated by SEM and PLM. DSC and PLM observation indicated a strong nucleation capability of inorganic whiskers for PET. Mechanical analysis results showed that the glass transition temperature, tensile strength, and modulus of the composites were greatly improved. A possible chemical bonding between PET chains and the surface of whiskers was observed by FTIR, TGA, and sedimentation experiment. It could be the main reason for the good dispersion and improved properties of the prepared composites. This work is important for the application of PET due to the low cost but high reinforcing efficiency of this inorganic whisker. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Mechanical and thermal properties of exfoliated graphite nanoplatelets reinforced polyethylene terephthalate/polypropylene composites

Exfoliated graphite nanoplatelets (GNP) reinforced composites materials based on blend of poly(ethylene terephthalate) (PET) and polypropylene (PP) were prepared by melt extrusion followed by injection molding. 10 parts per hundred resin (phr) styrene‐ethylene‐butylene‐styrene‐g‐maleic anhydride was added to the base formulation PET/PP (70/30) as a compatibilizer. PET/PP/GNP composites 0–5 phr were prepared and characterized using field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and Fourier transform infrared (FTIR) spectroscopy analysis. The morphological studies revealed a homogenous dispersion of GNPs in PET/PP blends up to 3 phr loading after which agglomeration occurred. Flexural strength was enhanced by 80% at 3 phr GNPs loading which was the highest value obtained. Interestingly, the highest value for the impact strength was also recorded at 3 phr loading. The thermal stability of the composites were generally improved at all filler loading with the highest at 3 phr. From the overall results, it is clear that the optimum concentration of GNPs in the PET/PP/GNP system in terms of both mechanical and thermal properties was 3 phr loading. Although, the mechanical and thermal properties of the composites were improved, the FTIR analysis did not reveal any chemical interaction between GNP and the polymer matrix. POLYM. COMPOS., 35:2029–2035, 2014. © 2014 Society of Plastics Engineers     

Effect of microfiber reinforcement on the morphology,electrical, and mechanical properties of the polyethylene/poly(ethylene terephthalate)/carbon nanotube composites

In situ microfiber reinforced conductive polymer composites consisting of high‐density polyethylene (HDPE), poly(ethylene terephthalate) (PET), and multiwalled carbon nanotube (CNT) were prepared in a twin screw extruder followed by hot stretching of PET/CNT phase in HDPE matrix. For comparison purposes, the HDPE/PET blends and HDPE/PET/CNT composites were also produced without hot stretching. Extrusion process parameters, hot‐stretching speed, and CNT amount in the composites were kept constant during the experiments. Effects of PET content and molding temperature on the morphology, electrical, and mechanical properties of the composites were investigated. Morphological observations showed that PET/CNT microfibers were successfully formed in HDPE phase. Electrical conductivities of the microfibrillar composites were in semi‐conductor range at 0.5 wt% CNT content. Microfiber reinforcement improved the tensile strength of the microfibrillar HDPE/PET/CNT composites in comparison to that of HDPE/PET blends and HDPE/PET/CNT composites prepared without hot stretching. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

工程塑料用PET的结晶性能研究

选用有机化蒙脱土、苯甲酸钠、聚乙二醇等物质为改性添加剂,采用正交试验L9(34)设计方法,制备了一系列在缩聚过程中添加各因素不同水平数的改性聚对苯二甲酸乙二醇酯(PET)。探讨了各因素对PET冷结晶温度(Tcc)、热结晶温度(Tmc)和结晶温度范围(△Tc=Tmc-Tcc)的影响趋势及其原因。实验结果表明,苯甲酸钠、聚乙二醇是PET很好的结晶改性剂,有机化蒙脱土对结晶改性作用次之。筛选出的优方案组方合成的PET试样,其结晶性能较常规PET大为改善。