显微镜图像分析研究聚丙烯/尼龙1010共混物相结构及其性能

用扫描电子显微镜图像分析研究了聚丙烯/聚酰胺1010共混物及其部分相容体系的相形态结构,计算了表征相结构和尺寸的结构参数,如分散相的平均直径、平均弦长和分散相的质心相关距等.并分别讨论了聚丙烯/聚酰胺1010共混物及其部分相容体系的相形态以及其结构参数与共混物组成的关系.测定了聚合物及其共混物体系的力学性能,讨论了共混物组成与力学性能的关系.聚丙烯/聚酰胺1010共混物的拉伸模量与组成的关系较为复杂,但其部分相容体系的拉伸模量与组成呈线性关系.聚丙烯/聚酰胺1010及其共混物体系的屈服强度与共混物组成均呈线性关系.表征相结构的两相平均弦长比(l-1/-l2)与组成以及共混物体系力学性能与组成的关系,二者相似.同时讨论了体系力学性能随相尺寸等的变化规律.     

聚丙烯/尼龙6挤出原位成纤后的牵引作用

用挤出机共混挤出聚丙烯和尼龙6，加工中尼龙6作为分散相在聚丙烯中形成微纤。改变挤出物挤出模口后所受的牵引作用的速度会产生材料形态与力学性能的变化。发现随牵引速度的提高，尼龙6微纤的平均直径变小，尺寸分布更均匀，力学性能也随之提高。差热分析表明，随牵引速度的增加聚丙烯与尼龙6的相容性略有提高，X-射线衍射分析表明拉伸作用对尼龙纤维晶体中分子链的取向无影响。     

Phase morphology development in PP/PA6 blends induced by a maleated thermoplastic elastomer

The effects of maleated thermoplastic elastomer (TPEg) on morphological development of polypropylene (PP)/polyamide 6 (PA6) blends with a fixed PA6 content (30 wt %) were investigated. For purpose of comparison, nonmaleated thermoplastic elastomer (TPE) was also added to the above binary blends. A comparative study of FTIR spectroscopy in above both ternary blends confirmed the formation of in situ graft copolymer in the PP/PA6/TPEg blend. Dynamic mechanical analysis (DMA) indicated that un‐like TPE, the incorporation of TPEg remarkably affected both intensity and position of loss peaks of blend components. Scanning electron microscopy (SEM) demonstrated that PP/PA6/TPE blends still exhibited poor interfacial adhesion between the dispersed phase and matrix. However, the use of TPEg induced a finer dispersion and promoted interfacial adhesion. Transmission electron microscopy (TEM) for PP/PA6/TPEg blends showed that a core‐shell structure consisting of PA6 particles encapsulated by an interlayer was formed in PP matrix. With the concentration of TPEg increasing, the dispersed core‐shell particles morphology was found to transform from discrete acorn‐type particles to agglomerate with increasing degree of encapsulation. The modified Harkin's equation was applied to illustrate the evolution of morphology with TPEg concentration. “Droplet‐sandwiched experiments” further confirmed the encapsulation morphology in PP/PA6/TPEg blends. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1050–1061, 2006     

超细聚酰胺6粒子增韧聚丙烯体系的研究

采用磨盘形力化学反应器室温下制备了聚丙烯 (PP) /聚酰胺 6 (PA6 )超细粉体 ,研究了其粒度、粒度分布及PA6超细粒子填充对PP力学性能的影响 .结果表明 ,磨盘形力化学反应器可有效实现PP/PA6的粉碎 ,所得粉体平均粒径达微米级 ,初级粒子尺寸甚至可达纳米级 ,粒度分布呈双峰分布状态 .在PA6和PP熔点之间的温度下加工可制得PA6超细粒于填充的PP/PA6共混体系 ,其力学性能明显好于PP/PA6简单共混体系 ,30 %PA6用量下 ,拉伸强度由 2 3 .2MPa提高至 2 9 3MPa ,Izod缺口冲击强度由 4.6 2kJ/m2 提高到6 .34kJ/m2 .形貌分析结果表明 ,由于基本保持了PA6超细粉体的原始尺寸 ,填充体系中PA6相区尺寸小、分布均匀 ,与使用增容剂得到的相区结构类似 .     

Atomic force microscopy study on blend morphology and clay dispersion in polyamide‐6/polypropylene/organoclay systems

The phase structure and clay dispersion in polyamide‐6(PA6)/polypropylene(PP)/organoclay (70/30/4) systems with and without an additional 5 parts of maleated polypropylene (MAH‐g‐PP) as a compatibilizer were studied with atomic force microscopy (AFM). AFM scans were taken from the polished surface of specimens that were chemically and physically etched with formic acid and argon ion bombardment, respectively. The latter technique proved to be very sensitive to the blend morphology, as PP was far more resistant to ion bombardment than PA6. In the absence of the MAH‐g‐PP compatibilizer, the organoclay is located in the PA6 phase; this finding is in line with transmission electron microscopic results. Further, the PP is coarsely dispersed in PA6 and the adhesion between PA6 and PP is poor. The addition of MAH‐g‐PP resulted in a markedly finer PP dispersion and good interfacial bonding between PA6 and PP. In this blend, the organoclay was likely dispersed in the PA6‐grafted PP phase. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43:1198–1204, 2005     

磨盘碾磨制备PA6/PP/SBS共混物的结构与性能

采用磨盘形力化学反应器,在室温下制备了PA6/PP超细混合粉体,与SBS共混制得PA6/PP/SBS共混物,测定了材料的力学性能并用TEM研究了材料在不同加工温度下相结构的变化.结果表明,通过固相力化学粉碎制备的PA6/PP混合微粉,改善了PA6与PP和SBS的相容性,促进了PA6及PP的分散和与SBS的相界面结合.在微粉填充量为4%～8%(质量分数)时,材料的拉伸强度大幅度提高,扯断伸长率保持不变.加工温度变化引起材料相结构的变化对材料性能产生显著影响.在PP熔融温度下加工,PP粒子产生粘连形成链状结构,可提高材料的力学性能.     

滑石粉及混炼顺序对PA6/PP/MAPP合金相形态及力学性能的影响

通过挤出和注射成型制备了滑石粉(Talc)填充的尼龙6/聚丙烯/马来酸酐接枝聚丙烯(PA6/PP/MAPP)合金, 研究了Talc和混炼顺序(一步法和PA6母料法)对合金相形态和力学性能的影响. 场发射扫描电镜(FESEM)分析结果表明, 添加Talc后注射样条中心部分的PP相由球状转变为沿流动方向取向的有分支的条状结构, 且用PA6母料法制样比用一步法制样的相形态更为精细. 溶解PA6相后对PP相进行热重分析(TGA), 确定了Talc在PA6相和PP相中的分布比例, Talc选择性分布于PA6相中. PA6母料法中Talc的分散好于一步法. 研究了材料的拉伸、 弯曲、 冲击、 热变形温度和动态力学性能, Talc的添加能够明显提高材料的刚性, 且母料法样品的性能优于一步法样品.     

微纤形态结构对PP/PA66原位微纤复合材料流变性能的影响

利用三角形排列三螺杆挤出机(triangle arrayed triple-screw extruder,TTSE)低温原位拉伸直接挤出制备了聚丙烯/聚己二酰己二胺(PP/PA66)原位微纤复合材料.通过三螺杆挤出机内部高强度的剪切-拉伸流场,研究了不同工艺参数如PA66含量、加工温度和螺杆转速下原位微纤复合材料中纤维的直径和长径比,并分析微纤长径比对复合材料动态流变性能的影响,且着重探究微纤长径比对凝胶点形成的影响.形貌分析结果显示,工艺条件极大地影响了微纤形貌,且PA66微纤长径比随分散相含量和螺杆转速的提高逐渐增加;动态流变数据说明,随着微纤长径比的增加,复合材料低频下的储能模量明显提高且比纯PP要高,同时,低频下的损耗角正切值降低且变化趋于平缓,而Cole-Cole圆半径显著增大,此时微纤复合材料表现出类凝胶的流变行为;原位微纤自缠结形成凝胶网络,微纤长径比越大,形成临界凝胶网络所需的PA66微纤含量越低,当长径比为210时,形成凝胶点时微纤含量仅3.80 wt%.     

Effect of maleic anhydride-grafted ethylene-propylene rubber on the mechanical, rheological and morphological properties of organoclay reinforced polyamide 6/polypropylene nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic modified montmorillonite (organoclay) were compatibilized with maleic anhydride-grafted ethylene-propylene rubber (EPRgMA). The blends were melt compounded in twin screw extruder followed by injection molding. The mechanical properties of PA6/PP nanocomposites were studied by tensile and flexural tests. The microstructure of the nanocomposite were assessed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The dynamic mechanical properties of the PA6/PP blend-based nanocomposites were analyzed by using a dynamic mechanical thermal analyzer (DMTA). The rheological properties were conducted from plate/plate rheometry via dynamic frequency sweep scans. The melt viscosity in a high shear rate region was performed by using a capillary rheometer. The strength and stiffness of the PA6/PP-based nanocomposites were improved significantly with the incorporation of EPRgMA. Adding EPRgMA to the PA6/PP blends resulted in a finer dispersion of the PP phase. TEM and XRD results revealed that the organoclay was dispersed more homogeneously in the presence of EPRgMA, however, mostly in the PA6 phase of the blends. DMTA results showed that EPRgMA worked as an effective compatibilizer. The storage (G′) and loss moduli (G″) assessed by plate/plate rheometry of PA6/PP blends increased with the incorporation of EPRgMA and organoclay. Furthermore, the apparent shear viscosity of the PA6/PP blend increased significantly for the EPRgMA compatibilized PA6/PP/organoclay nanocomposite. This was traced to the formation of an interphase between PA6 and PP (via PA6-g-EPR) and effective intercalation/exfoliation of the organoclay.     

Thermal studies on polypropylene/polyamide‐6 blends modified by succinic anhydride and succinyl fluorescein grafted polypropylenes

This study investigates the role played by two different interface agents on the basis of atactic polypropylene in the continuous/disperse phase polypropylene/polyamide‐6 (PP/PA6) system. The two agents used were obtained at the authors' laboratories from an atactic polypropylene byproduct derived from industrial polymerization reactors and consist of two grafted polymers containing either succinic anhydride (a‐PP‐SA) or both succinyl‐fluorescein and succinic anhydride grafted groups (a‐PP‐SF/SA). The role of these grafted polymers as compatibilizers in PP/PA6 polymer blends has been confirmed in previous investigations on the basis of their macroscopic behavior. This work investigates the thermal study of these blends where polypropylene acts as the polymer matrix and polyamide as the dispersed phase. Under isothermal conditions, thermal analysis agrees with the changes in the overall system behavior caused by the presence of the interface agents. These aspects were confirmed by polarized light microscopy that showed the morphology of the blends before and after modification with a‐PP‐SA or a‐PP‐SF/SA. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1307–1315, 2002     

Phase morphology, crystallisation behaviour and mechanical properties of isotactic polypropylene/high density polyethylene blends

The phase morphology, crystallisation behaviour and mechanical properties of isotactic polypropylene (iPP)/high density polyethylene (HDPE) blends were investigated. It was found that the properties are intimately related to each other. The morphology of the blends showed a two phase structure in which the minor phase was dispersed as domains in the major continuous matrix phase. The domain size of the dispersed phase increased with increasing concentration of that phase due to coalescence. It was also found that the domain size of the dispersed phase depends on the viscosity difference between the two phases. For a given HDPE/iPP blend, where HDPE is the matrix and iPP is the dispersed phase, the iPP domains were smaller than HDPE domains of the corresponding iPP/HDPE blend where iPP is the matrix and HDPE is the dispersed phase. A co-continuous morphology was observed at 50/50 PP/HDPE composition. Crystallinity studies revealed that blending has not much effect on the crystalline melting point of polypropylene and high density polyethylene. The crystallisation enthalpy and heat of fusion values of HDPE and PP in the blend were decreased as the amount of the other component increased. The variation in percent crystallinity of HDPE and PP in the blend was found to depend on the morphology of the blend. All the mechanical properties except Young's modulus and hardness showed negative deviation from the additivity line. This is due to the incompatibility of these blends.     

PP/PA66原位复合材料的增强和增韧效应

用挤出 拉伸 注塑法制得了增强又增韧的PP PA66原位复合材料 ,以未经拉伸的普通共混材料作对照 ,研究了PA66质量含量 (cd)对材料相形态和力学性能的影响及其作用机制 .结果表明 ,当cd 由 0 %增至2 0 %时 ,原位形成的PA66纤维数量增多 ,纤维直径及其分散性以cd =1 5 %为界先减小后增大 ,残留的PA66粒子数也增多 ;纤维数量的增多和纤维网络的发展导致材料冲击强度持续增高 ;纤维及粒子对基体的增刚作用使材料杨氏模量增高趋于极限值 ;受分散相对基体增强效应和两相弱粘结界面缺陷效应的综合影响 ,材料的拉伸强度以cd =1 5 %为界先增高后降低     

PP-g-(GMA-co-St)对PA6/PC共混物的反应增容作用

用红外、扫描电镜、熔体流动速率和力学性能等测试方法,研究了甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)多单体熔融接枝聚丙烯[PP-g-(GMA-co-St)]对PA6/PC共混物的反应增容作用.研究结果表明,在熔融共混过程中,PP-g-(GMA-co-St)中的环氧基与PA6的端氨基及PC的端羟基原位生成的接枝共聚物有效地降低了共混物相间的界面张力,明显提高了共混物相界面的粘着力.少量的PP-g-(GMA-co-St)就能使PA6和PC的相容性得到显著改善.当PP-g-(GMA-co-St)的质量分数为10%时,共混物分散相的相区尺寸细化到0.2μm,其力学性能也有较大提高.PA6/PC/PP-g-(GMA-co-St)共混物的力学性能均衡,达到了弹性体增韧体系难以达到的效果.即使PP-g-(GMA-co-St)组分含量为20%时,共混物仍能保持较好的力学性能,特别是在共混物的韧性得以提高的同时,其强度和伸长率也提高.     

Morphology of isotactic polypropylene-polyamide 66 blends and their mechanical properties

Compounds were prepared with isotactic polypropylene (iPP) matrix and recycled polyamide 66 fibres (PA66), which were obtained as soft waste in industrial production process. Blends with pristine PA66 pellets were prepared as comparison. The blends showed the presence of PA66 particles dispersed in the PP continuous phase. Considering the incompatibility of the two polymers the addition of isotactic polypropylene grafted with maleic anhydride (iPPgMA) as compatibilizer was investigated: the blends were characterized by thermal, mechanical, dynamic-mechanical and morphological analyses. The presence of the compatibilizer significantly influences the morphology of the blends, inducing a finer dispersion and promoting interfacial adhesion. The characterization of pristine and recycled PA66 did not show a meaningful difference in the value of molecular weight, on the other hand marked differences were presented in the flexural moduli of the two materials; analogous differences were exhibited by the blends: compounds prepared with recycled PA66 showed flexural moduli higher than compatibilized blends with pristine PA66.     

PP/PP-g-MAH/PA6共混物结构与可纺性研究

运用DSC、SEM、纺丝成形等手段研究了增容剂聚丙烯接枝马来酸酐 (PP g MAH)对聚丙烯 聚酰胺 6(PP PA6 )共混物结构和性能的影响 .结果表明 ,共混物呈典型海岛型两相结构 ;增容剂PP g MAH与PA6之间的在位反应改善了PP PA6共混体系的相容性 ,使共混物中PA6的热结晶峰消失 ,PP的结晶生长速率和成核速率降低 ,可纺性提高     

多组分单体接枝聚丙烯/尼龙6反应共混物结晶行为研究

用多组分熔融接枝的方法将甲基丙烯酸缩水甘油酯 (GMA)和苯乙烯 (St)共同接枝到聚丙烯 (PP)上 ,制得具有较高GMA接枝率的多单体接枝聚丙烯 ,PP g (GMA co St) .将PP g (GMA co St)与尼龙 6 (PA6 )进行共混 ,利用扫描电镜 (SEM) ,差示扫描量热计 (DSC)和广角X射线衍射 (WAXD)对共混物的形态和结晶进行了研究 .在共混过程中 ,PP g (GMA co St)与PA6反应原位生成了PP g PA6 ,有效改善了共混物的相容性 ,分散相尺寸明显减小 .在PP g (GMA co St) PA6为 3 7的体系中 ,PP g (GMA co St)出现分级结晶现象 ,其在较低温度下的结晶属于均相成核结晶 .在PP g (GMA co St) PA6为 7 3的体系中 ,由于PA6相分散细微 ,在通常结晶温度下不结晶 ,而是在低温下均相成核与PP g (GMA co St)同时结晶 .WAXD证实体系中接枝PP ,PA6为分别结晶 ,无共晶或新的晶型产生     

Viscoelastic behavior of polypropylene/nitrile rubber thermoplastic elastomer blends: Application of Kerner's models for reactively compatibilized and dynamically vulcanized systems

The viscoelastic properties of binary blends of nitrile rubber (NBR) and isotactic polypropylene (PP) of different compositions have been calculated with mean‐field theories developed by Kerner. The phase morphology and geometry have been assumed, and experimental data for the component polymers over a wide temperature range have been used. Hashin's elastic–viscoelastic analogy principle is used in applying Kerner's theory of elastic systems for viscoelastic materials, namely, polymer blends. The two theoretical models used are the discrete particle model (which assumes one component as dispersed inclusions in the matrix of the other) and the polyaggregate model (in which no matrix phase but a cocontinuous structure of the two is postulated). A solution method for the coupled equations of the polyaggregate model, considering Poisson's ratio as a complex parameter, is deduced. The viscoelastic properties are determined in terms of the small‐strain dynamic storage modulus and loss tangent with a Rheovibron DDV viscoelastometer for the blends and the component polymers. Theoretical calculations are compared with the experimental small‐strain dynamic mechanical properties of the blends and their morphological characterizations. Predictions are also compared with the experimental mechanical properties of compatibilized and dynamically cured 70/30 PP/NBR blends. The results computed with the discrete particle model with PP as the matrix compare well with the experimental results for 30/70, 70/30, and 50/50 PP/NBR blends. For 70/30 and 50/50 blends, these predictions are supported by scanning electron microscopy (SEM) investigations. However, for 30/70 blends, the predictions are not in agreement with SEM results, which reveal a cocontinuous blend of the two. Predictions of the discrete particle model are poor with NBR as the matrix for all three volume fractions. A closer agreement of the predicted results for a 70/30 PP/NBR blend and the properties of a 1% maleic anhydride modified PP or 3% phenolic‐modified PP compatibilized 70/30 PP/NBR blend in the lower temperature zone has been observed. This may be explained by improved interfacial adhesion and stable phase morphology. A mixed‐cure dynamically vulcanized system gave a better agreement with the predictions with PP as the matrix than the peroxide, sulfur, and unvulcanized systems. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1417–1432, 2004     

Structure and properties of an hybrid system based on bisphenol A polycarbonate modified by A polyamide 6/organoclay nanocomposite

Blends of poly(carbonate of bisphenol A) (PC) with minute amounts of a nanocomposite based in polyamide 6 (PA6) with a layered organoclay (nPA6) were obtained upon melt mixing by varying the contents of both nPA6 and organoclay. The ternary nanocomposites (NC) were composed of a PC-rich matrix with some mixed PA6 present, and by a neat nPA6 dispersed phase. Upon dissolution of the matrix of the NC’s, the dispersed phase showed a highly fibrillar morphology that resembled that of thermoplastic/liquid crystalline polymer (LCP) blends. The cryogenically fractured surfaces observed by SEM showed a very fine particle size that was attributed to the presence of PA6 in the matrix and indicated a low interfacial tension. The Young’s modulus behaviour is proposed to be a consequence of the slight orientation of the PC-rich matrix and the highly fibrillated and oriented nPA6 dispersed phase. The important reinforcement effect of the dispersed phase is attributed to the additive effects of its large degree of orientation, and the reinforcing effect of the organoclay.     

纳米刚性微粒与橡胶弹性微粒同时增强增韧聚丙烯的研究

通过力学性能测试、动态力学试验、ＤＳＣ 分析以及材料断面形貌与结构分析等手段,对以纳米二氧化硅（ＳｉＯ２） 为刚性微粒、以三元乙丙橡胶（ＥＰＤＭ） 为弹性微粒组成的聚丙烯（ＰＰ）／ 纳米ＳｉＯ２／ＥＰＤＭ 的同时增强增韧效果进行了研究．结果显示,上述两种微粒可同时大幅度提高ＰＰ 的韧性、强度和模量,当ＰＰ／ 纳米ＳｉＯ２／ＥＰＤＭ 为８０／３／２０ 时,两种微粒体现较明显的协同增韧效应．纳米ＳｉＯ２ 可提高ＰＰ 的结晶温度和结晶速度,并使球晶细化．纳米ＳｉＯ２ 刚性微粒在ＰＰ连续相中以微粒团聚体形态分布,构成团聚体的平均微粒数约为６ ～７ ,其与ＰＰ基体表现出较强的结合牢度．ＰＰ／ 纳米ＳｉＯ２／ＥＰＤＭ 的综合性能已接近或达到工程塑料的性能．     

Crystallization of polyamide confined in sub‐micrometer droplets dispersed in a molten polyethylene matrix

The crystallization of submicrometer PA6 droplets dispersed in an ethylene‐1‐octene copolymer matrix, using PE‐g‐MA as a compatibilizer agent, is investigated. This system shows a nonconventional mechanical behavior at high temperatures. Up to ～100 °C above the final melting temperature of the ethylene‐1‐octene copolymer matrix, the system shows good thermal and mechanical properties including dimensional stability. Because of the dispersed phase morphology of the system, so‐called fractionated/homogeneous crystallization takes place leading to an extra supercooling of PA6: ～50 °C compared to the bulk PA6 crystallization temperature. Thus—though this is most probably just of interest for small‐scale research—the system can be processed at lowered temperatures while still providing exceptional high‐temperature properties. While the matrix is in the melt state when crystallization of the dispersed PA6 phase occurs, the possibility of matrix induced crystallization is absent, contrary to almost all of the ‘dispersed droplets in a matrix’ systems reported so far. The kinetics of this phenomenon is investigated in detail by DSC: the existence of fractionated/homogeneous crystallization is shown to be related to the lack of active nuclei in the dispersed droplets by means of self‐seeding experiments. The occurrence of extensive cold crystallization of PA6 in the confined environment is studied as is the crystallization kinetics, including the characterization of its time dependences showing its sporadic nature. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 815–825, 2006