PP/EVOH共混物结构与性能研究

采用丙烯酸接枝聚丙烯（PP-g-AA）、衣康酸接枝聚丙烯 (PP-g-ITA)、马来酸酐接枝聚丙烯 (PP-g-MAH)3种相容剂增容聚丙烯（PP）/乙烯-乙烯醇共聚物(EVOH)共混体系,研究了共混体系的相容性、热性能、力学性能和阻隔性能。红外光谱分析表明,相容性的改善源于相容剂与EVOH之间形成的酯键和氢键。扫描电镜显示,PP-g-AA、PP-g-ITA、PP-g-MAH的增容作用依次增强,共混体系中相容剂增容作用越强,分散相尺寸越小,界面结合越牢固。差示扫描量热分析发现,PP/EVOH增容共混体系中EVOH组分的结晶温度低于不含相容剂的共混体系EVOH组分的结晶温度,PP组分的结晶温度变化则相反。增容共混体系与不含相容剂的共混体系相比,拉伸强度提高了10 MPa,吸油率降幅达0.8 %。     

衣康酸接枝PE-HD增容PA6／PE-HD共混物的研究

采用反应型双螺杆挤出机和熔融接枝技术制备了一系列高密度聚乙烯（PE-HD）接枝物，采用红外光谱表征了衣康酸接枝PE-HD（PE-HD-g-ITA）和衣康酸-苯乙烯共聚物接枝PE-HD[PE-HD-g-（ITA-co-St）]的结构，并研究了接枝率（GR）和熔体流动速率与单体和引发剂用量的关系；制备了PE-HD-g-ITA增容PA6／PE-HD共混物，研究了共混物的力学性能和形态结构。结果表明：引入相容剂PE-HD-g-ITA，共混体系的冲击强度较纯PA6提高近1．7倍；共混体系两相界面变得模糊，分散相尺寸减小，说明相容剂能明显改善共混物两相界面间的黏结，改善体系的分散状况，两相问的相容性得到明显提高；相容剂对共混物两相熔点（Tg）的影响不大，PA6相结晶度稍有下降，PE-HD相结晶度却明显增加。     

相容剂对PE-HD／PET共混合金性能的影响

以乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯三元共聚物（PTW）作为高密度聚乙烯（PE-HD）／聚对苯二甲酸乙二醇酯（PET）共混合金的反应性相容剂，采用熔融挤出法制备了以PE-HD为基体的PE～Hi）／PET、共混合金。通过力学性能和流变性能测试，扫描电镜（SEM）和动态力学分析（DMA）等手段，研究丁PTW对共混合金性能的影响。结果表明：PTW提高了体系的综合性能，当PE-HD／PET配比为90／10，PTW含量在5份时，其缺口冲击强度提高了近400％，拉伸强度和断裂伸长率分别提高了25％和50％，同时改善了共混合金的加工性能。SEM分析表明PTW的加入增大了共混合金的界面相互作用，促进了分散相粒子的细化，从而提高丁体系相容性，DMA测试表明，PTW的加入使PET的玻璃化转变温度向PE—HD的玻璃化转变温度靠近：     

（PE-HD／SEBS）-g-MAH对PE-HD／木粉复合材料增容的研究

采用转矩流变仪制备出马来酸酐（MAH）接枝PE-HD）／氢化（苯乙烯-丁二烯-苯乙烯）共聚物（SEBS）（PE-HD/SEBS）-g-MAH作为PE-HD／共混物木粉复合材料的界面相容剂，并研究了制备过程中转矩的变化，结果表明，体系的转矩随着MAH和引发剂过氧化二异丙苯含量的增加而增加，苯乙烯促进了MAH和PE-HD／SEIKS的反应；通过傅里叶红外分析证实了MAH接枝到聚合物上。（PE-HD／SEBS）-g-MAH能明显地提高PE-HD／木粉复合材料的力学性能，当其添加量为2％（质量分数，下同）时复合材料的拉伸强度、弯曲强度和冲击强度分别增加了157％、146％和145％；扫描电镜也能观察到加入相容剂的复合材料界面粘接非常好，进一步证实了（PE-HD／SEBS）-g-MAH提高了复合材料的界面相容性。     

共聚焦拉曼成像技术研究PE-LD/EVOH共混物的三维相结构

利用共聚焦拉曼成像技术研究了低密度聚乙烯（PE-LD）/乙烯-乙烯醇共聚物（EVOH）共混物中各相在压塑样品水平方向、深度方向和三维空间的分布情况,首次获得了PE-LD/EVOH共混物的三维相结构,并直观地将相区与共混物化学成分相对应。结果表明,PE-LD/EVOH共混物为不相容体系;当EVOH的质量分数为20%时,其作为分散相,以较规则的圆柱体形态分散于PE-LD基体中,圆柱直径尺寸在3～6μm范围内。加入马来酸酐接枝聚乙烯（PE-gMAH）作为相容剂后,共混物的相态结构发生显著变化,分散相形状由规则变为不规则,截面的平均尺寸减小到约2μm,这说明PE-g-MAH可显著增强PE-LD与EVOH两组分间的界面相容性。     

PCL增韧PLA共混材料的制备与性能研究

在聚乳酸(PLA)基体中加入聚己内酯(PCL)、柠檬酸三丁酯(TBC),通过熔融共混制备了PLA/PCL共混材料,并对其相容性、力学性能、热性能等进行了研究。结果表明:PLA/PCL为不相容体系,TBC作为相容剂对体系的韧性和强度影响较大;在TBC的作用下,共混材料两相之间发生了酯交换反应,生成界面相容剂,降低了PCL分散相的尺寸,改善了两相之间的相容性,提高了共混材料的韧性。当PLA与PCL的质量比为80/20、TBC的质量分数占共混材料总质量的8%时,共混材料的断裂伸长率可达125%,冲击强度值可达9.83kJ/m2。同时,共混材料的冷结晶峰消失,结晶趋于完善。     

相容剂对PP/PP-g-MAH/EVOH中空纤维硬弹性的影响

采用乙烯-乙烯醇共聚物(EVOH)共混亲水改性聚丙烯(PP),并且,聚丙烯接枝马来酸酐(PP-g-MAH)作为相容剂,制备PP/PP-g-MAH/EVOH共混物,再经熔融纺丝制备具有硬弹性的PP/PP-g-MAH/EVOH中空纤维。然后,对共混物亲水性能、中空纤维微观形态和力学性能进行测试表征,分析相容剂PP-g-MAH对PP/PP-g-MAH/EVOH中空纤维亲水性与硬弹性行为的影响。结果表明,加入EVOH可以改善PP/PP-g-MAH/EVOH共混体系的亲水性,增容共混体系提高了共混体系的亲水性。PEMAH-0由于受到不相容的两相界面的影响,中空纤维的弹性回复率与强度显著降低,硬弹性较差。PP-g-MAH可以改善两相间相容性,细化EVOH的相岛结构,提高了PP/PP-g-MAH/EVOH中空纤维的强度与弹性回复率,使其具有较好的硬弹性。     

PP/EVOH/PA6共混物的性能研究

以聚丙烯接枝马来酸酐(PP-g-MAH)为相容剂,制备了聚丙烯(PP)/乙烯-乙烯醇共聚物(EVOH/)聚酰胺6(PA6)共混物,研究了PP/EVOH/PA6三元共混物的相容性、流变性能、阻隔性能、力学性能、热性能及形态结构。结果表明:相容剂与EVOH和PA6间发生了反应,提高了共混物的相容性;相容剂的加入提高了PP、EVOH、PA6的结晶温度,增强了PP与EVOH和PA6间的黏合力,降低了界面张力;EVOH占EVOH/PA6总量68%的三元共混物吸油率最小,当相容剂用量为5份时,PP/EVOH/PA6三元共混物吸油率比PP/EVOH二元共混物降低了8%。     

相容剂对LLDPE/PET共混材料性能的影响

选用不同相容剂对LLDPE/PET共混材料进行增容改性,研究了不同相容剂对LLDPE/PET共混材料力学性能、热性能、流变性能和微观形貌的影响。结果表明:相容剂的加入,能够明显提升共混材料的力学性能,当相容荆含量为3%时,拉伸强度比未加相容剂时最大提升了25.4%,相容剂含量为9%时,冲击强度最大提升了156%。随着相容剂含量的增加,共混材料的熔体流动性逐渐降低,两相基体熔点向中间温度变化,LLDPE结晶温度和结晶度先减小后增大,过多的相容剂会起到成核剂的作用。微观形貌分析表明:相容剂能够降低分散相粒径大小,增加界面黏结性。综合来看,LLDPE-g-MAH对共混材料相容性的提升效果要优于LDPE-g-GMA。     

相容剂对PC/ABS共混物性能的影响

本文分别研究了马来酸酐接枝ABS(ABS-g-MAH)与甲基丙烯酸甲酯/丁二烯/苯乙烯共聚物(MBS)作为相容剂对PC/ABS共混体系相容性、力学性能、形态结构的影响.研究结果表明:当相容剂MBS加入PC/ABS共混体系中后,不仅能够显著改善PC/ABS共混物的相容性,明显降低分散相的粒径,而且能够使PC/ABS共混物在保持较高的拉伸强度的同时,大幅度地提高共混物的缺口冲击强度和断裂伸长率;而相容剂ABS-g-MAH的加入对共混体系的缺口冲击强度的改善不明显,但其断裂伸长率增幅较大.     

SEBS弹性体增韧改性PE-HD/PS共混物及其相容性研究

采用聚苯乙烯嵌段聚（乙烯亚丁基）嵌段聚苯乙烯（SEBS）弹性体增韧改性高密度聚乙烯（PE-HD）/聚苯乙烯（PS）共混物,通过哈克转矩流变仪制备了PE-HD/PS/SEBS三元共混物,采用扫描电子显微镜（SEM）、旋转流变仪、冲击试验机、热重分析仪（TG）和差式扫描量热仪（DSC）等手段研究了PE-HD/PS/SEBS共混体系的相容性。结果表明,SEBS对共混体系具有良好的增容作用,但当SEBS添加量大于8 %(质量分数,下同)后,部分SEBS出现团聚现象,导致共混体系相容性降低;SEBS的引入对共混物的耐热性影响不大,共混物中连续相PE-HD的熔点稍有降低;随着SEBS添加量的增加,共混物的悬臂梁缺口冲击强度大幅提高。     

Influence of phthalic anhydride and bioxazoline on the mechanical and morphological properties of biodegradable poly(lactic acid)/poly[(butylene adipate)‐co‐terephthalate] blends

Poly(lactic acid) (PLA)/poly[(butylene adipate)‐co‐terephthalate] (PBAT) blends were fabricated by melt blending, with 2,2′‐(1,3‐phenylene)bis(2‐oxazoline) (BOZ) and phthalic anhydride (PA) used as compatibilizers. It was found that a small amount of BOZ or PA greatly increased the elongation at break of the PLA/PBAT blends without sacrificing their high tensile strength. Scanning electron microscopy results revealed that the PBAT particles became finer and were uniformly dispersed in the matrix when the compatibilizers were incorporated, which indicated that the interfacial bonding and compatibilization between PLA and PBAT were improved in the presence of the compatibilizers. Compared with PLA/PBAT blends, the molecular weight of PLA/PBAT/PA/BOZ blends was increased due to chain‐extending reactions. Differential scanning calorimetry results suggested PBAT decreased the crystallization rate and crystallinity of PLA in the blends. Moreover, the glass transition temperature of PBAT was further decreased when the compatibilizers were used. © 2013 Society of Chemical Industry     

Structured latex particles based on natural rubber for high-impact polymer blends

Natural latex (NR) particles, modified with a hard shell of poly(methyl methacrylate) (PMMA) and with a substructure of PMMA (type "NR-M") or polystyrene (type "NR-SM"), were tested as compatibilizers in blends of polycarbonate (of bisphenol A, PC) and PMMA or PS. During melt blending, the modified NR particles were torn apart, from an original size of >0.5 μm down to ≅0.1 μm in diameter. Two different types of particle distribution were observed in the blends: in PC/PMMA/NR-M blends, the NR-M particles were dispersed in the PMMA phase, whereas, in PC/PS/NR-SM blends, the NR-SM particles formed interface layers between PC and PS phase domains. The latter blend morphology, distinguished by continuous rubbery interface layers of NR-SM, turned out to be mechanically excellent in injection-moulded parts. The poor impact strength of PC/PS was raised by an order of magnitude. The effect depends on the orientation in the injection-moulded test bars.     

Tailoring morphology to improve the gas‐barrier properties of thermoplastic polyurethane/ethylene‐vinyl alcohol blends

The morphology and helium‐barrier properties of thermoplastic polyurethane (TPU)/ethylene‐vinyl alcohol (EVOH) blends with and without dicumyl peroxide (DCP) were investigated by melting blending. A lamellar dispersion of EVOH with good helium‐barrier properties was observed in the TPU matrix with DCP. The evolution of the morphology of the blends is mainly related to the variation of the viscosity ratio between the dispersed phase and the matrix phase. Compared with pure TPU, lamellar morphology increased the helium‐barrier properties of the TPU/EVOH (60/40) blend by as much as 10‐fold. We also explored the effects of composition, DCP content, and blending sequence on the morphology and helium‐barrier properties of the TPU/EVOH blends. The morphology of the blends ranged from a droplet‐matrix to a lamellar structure. We determined the optimum amount of DCP to improve the helium barrier of the blends. The helium‐barrier properties of the blends prepared by direct blending were superior to those of the blends prepared by two‐segment blending, and the blends prepared by direct blending exhibited a well‐developed lamellar morphology. We compared the permeability of the samples with the theoretical results to explain the relationship between morphology and helium‐barrier properties. POLYM. ENG. SCI., 56:922–931, 2016. © 2016 Society of Plastics Engineers     

Incorporating amylopectin in poly(lactic acid) by melt blending using poly(ethylene‐co‐vinyl alcohol) as a thermoplastic carrier. (I) morphological characterization

In this study, the possibility of using a biodegradable grade of thermoplastic poly(ethylene‐co‐vinyl alcohol) with high (71 mol %) vinyl alcohol (EVOH‐29), as a carrier to incorporate the renewable and biodegradable component amylopectin (AP) into poly(lactic acid) (PLA) through melt blending, was investigated. The effect of using a plasticizer/compatibilizer (glycerol) in the blend systems was also investigated. In a first step, the EVOH/AP blends were produced and thereafter, in a second step, these were mixed with PLA. In this first study, the blend morphology was investigated using optical microscopy, scanning electron microscopy and Raman imaging spectroscopy and the thermal properties were measured by differential scanning calorimetry. Despite the fact that EVOH and AP are both highly polar, their blends were immiscible. Still, the blends exhibited an excellent phase dispersion on a micron level, which was enhanced further by the addition of glycerol. A good phase dispersion was finally observed by incorporation of the latter blends in the PLA matrix, suggesting that the proposed blending route can be successfully applied for these systems. Finally, the Differential scanning calorimetry (DSC) data showed that the melting point of EVOH dropped in the EVOH/AP blends, but the properties of the PLA phase was still relatively unaffected as a result of blending with the above components. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

高刚性高韧性PE-HD/E-TMB共混物的性能

用自制增韧母料(E-TMB)与高密度聚乙烯(PE-HD)热机械共混制得PE-HD/E-TMB共混物,研究了E-TMB中基体树脂和丁苯弹性体质量比(H/E)对共混物力学性能、熔体流动速率(MFR)和热稳定性能的影响.结果表明,当PE-HD/E-TMB共混物中丁苯弹性体的质量分数为6.3%时,E-TMB使PE-HD在保持优...     

The effect of MBS on the heat resistant,mechanical properties,thermal behavior and rheological properties of PLA/EVOH blend

This work focuses on improve the mechanical properties of poly(lactic acid)/poly(ethylene-co-vinyl alcohol) (PLA/EVOH) blend and simultaneously remained a high Vicat softening temperature (VST) using appropriate contents of methyl methacrylate–butadiene–styrene copolymer (MBS) via simple melt blending. The effects of MBS on the heat resistant, mechanical properties, thermal properties and rheological behavior were examined in detail with various techniques. The VST of neat PLA significantly increased to 159 °C from 66.8 °C after blending with 50 wt% EVOH. However, the VST was gradually decreased with increasing MBS content but were still much higher than that of neat PLA. On the basis of the tensile and impact tests results, PLA/EVOH/MBS blends showed a considerably higher elongation at break and impact strength. For all PLA/EVOH/MBS blends, the thermal stability was increased compared than that of PLA/EVOH blend without MBS. With increasing MBS content, the complex viscosity and storage modulus of PLA/EVOH blend increased, especially at low frequencies, indicating that MBS enhanced the chain entanglement in the PLA/EVOH matrix. In addition, the results Han curves and Cole–Cole plots indicated that the relaxation time was increased when MBS was added.     

PP／PE-HD共混体系发泡成型及机理分析

采用PP与PE-HD共混的方法来改善PP的发泡性能，并从共混体系的熔体强度和结晶性能两个方面分析PE-HD含量对泡孔结构的影响机理。结果表明，PP／PE-HD共混体系的熔体强度随着PE-HD含量的增加先升高后减小，在含量为30％（质量分数，下同）时熔体强度最高。随着PE-HD含量的增加，共混体系中PP和PE-HD的熔点先升高后降低，PP的结晶度先减小后增大，而PE-HD的结晶度却逐渐增加。在含量为30％时，PP和PE-HD的熔点最高，PP的结晶度最小。PP与PE-HD共混以后，泡孔结构有了很大改善，且与熔体强度和结晶度相对应，泡孔结构在PE-HD含量为30％时最好。     

The effect of maleated compatibilizers on the structure and properties of EVOH/clay nanocomposites

The effect of compatibilizers on the blending torque, crystallization behavior, intercalation level, thermal stability and morphology of EVOH/treated clay systems was investigated. Maleic anhydride‐grafted ethylene vinyl acetate (EVA‐g‐MA) or maleic anhydride‐grafted linear low density polyethylene (LLDPE‐g‐MA) were used as compatibilizers of EVOH with clay, in various concentrations (1, 5 and 10 wt%). The blends were processed using Brabender Plastograph and characterized by XRD, SEM, DSC, DMTA and TGA. X‐ray diffraction shows advanced intercalation within the galleries when the compatibilizers were added. Unique results were obtained for the EVOH/clay/compatibilizer systems, owing to a high level of interaction developed in these systems, which plays a major role. Thermal analysis showed that with increasing compatibilizer content, lower crystallinity levels result, until at a certain content no crystallization has taken place. Significantly higher viscosity levels were obtained for the EVOH/clay blends compared to the neat polymer, as seen by a dramatic torque increase when processed in the Brabender machine. The DMTA spectra showed lower T_g values for the compatibilized nanocomposites compared to the neat EVOH and the uncompatibilized composites. Storage modulus was higher compared to the uncompatibilized EVOH/clay blend when EVA‐g‐MA compatibilizer was added (at all concentrations), and only at low contents of LLDPE‐g‐MA. TGA results show significant improvement of the blends thermal stability compared to the neat EVOH, and to the uncompatibilized blend, indicating an advanced intercalation.