PP-g-MAH对PP/PA6共混物的增容作用

采用熔融接枝法,考察了单体和引发剂用量对聚丙烯(PP)/马来酸酐(MAH)接枝物接枝率的影响。将PP-g-MAH作为PP/尼龙6(PA6)共混物的增容剂,并利用SEM、XRD、DSC-TGA和万能试验机等测试手段对PP-g-MAH增容改性PP/PA6共混体系进行了研究。结果表明,PP-g-MAH接枝物对PP/PA6共混物具有良好的增容效果,PP结晶得到细化,共混物的力学性能和耐高温性能得到改善。     

界面作用对PP/PA6共混体系相结构与力学性能的影响

研究了两种相容剂马来酸酐接枝聚丙烯(PP-g-MAH)、马来酸酐接枝乙烯-辛烯共聚物弹性体(POE-g-MAH)对聚丙烯/尼龙6(PP/PA6)共混体系力学性能的影响.通过扫描电子显微镜(SEM)、差示扫描量热仪(DSC)分析和力学性能测试,研究了相容剂POE-g-MAH和PP-g-MAH对PP/PA6共混物相容性、形态结构和力学性能的影响.研究结果表明:两种相容剂的加入都使PP/PA6体系的相容性增加,但PP-g-MAH的加入主要表现为增强效果,而POE-g-MAH的加入主要表现为增韧效果.     

接枝物含量对高层建筑用GF/PP复合材料性能的影响

为了提高高层建筑用材料的力学性能,采用熔融共混的方法,在玻璃纤维(GF)增强聚丙烯(PP)复合材料中加入马来酸酐接枝PP(PP-g-MAH)与马来酸酐接枝聚烯烃(POE-g-MAH),分析接枝物含量对复合材料拉伸性能、弯曲性能以及冲击性能的影响。研究表明：当POE-g-MAH或PP-g-MAH的加入量为4 g时,复合材料的流动性明显改善,达到了最大熔体流动速率。当基体中接枝物含量上升后,复合材料的拉伸强度表现为先增大后减小的变化趋势,弯曲强度以及弯曲弹性模量都出现了先增大后减小的变化趋势,并在含有4 g接枝物时达到最大。当复合材料中接枝物含量增大后,含有POE-g-MAH接枝物的复合材料的冲击强度迅速增大。扫描电镜显示,加入接枝物后GF表面上存在明显附着物,GF和PP基体之间形成了良好相容性。     

PP-g-MAH和SMAH增容PP/PA11的研究

分别用马来酸酐接枝聚丙烯(PP-g-MAH)和(苯乙烯/顺丁烯二酸酐)无规共聚物(SMAH)作增容剂,对聚丙烯(PP)／尼龙11(PA11)共混体系的拉伸性能、缺口冲击性能进行了研究。傅立叶转换红外光谱表明,SMAH的增容机理与PP-g-MAH不同。比较了两种增容体系的差示扫描量热曲线,PP-g-MAH增容体系中PP的熔融温度向更高温度移动。     

PP固相接枝马来酸酐增容PP／PA6研究

以高速搅拌器为反应器,利用聚丙烯(PP)粉料自身摩擦生热,制备出不同接枝率的聚丙烯固相接枝马来酸酐(PP-g-MAH);通过对熔体流动速率测定、差热分析以及偏光显微分析,研究了PP-gMAH对PP／聚酰胺6(PA6)共混体系的增容作用及其对共混体系力学性能的影响。结果表明:采用固相法制备的PP-g-MAH可以明显提高PP与 PA6的相容性,PP-g-MAH接枝率高(1．2％)增容效果好;添加固相接枝PP-g-MAH的PP／PA6共混体系的拉伸强度和冲击强度高于添加熔融接枝物的PP／PA6共混体系。     

增容剂对PP/r-PET共混体系结构与性能影响

采用熔融接枝法制备了聚丙烯(PP)接枝甲基丙烯酸缩水甘油酯接枝物(PP-g-GMA)和聚丙烯接枝马来酸酐接枝物(PP-g-MAH),并用PP-g-GMA和PP-g-MAH作为PP/回收聚对苯二甲酸乙二醇酯(PP/r-PET)共混体系(质量份之比100/12)的增容剂。通过对共混体系进行分析,研究了PP-g-GMA和PP-g-MAH对PP/r-PET共混体系结构与性能的影响。结果表明:成功制备了PP-g-GMA和PP-g-MAH;PP-g-GMA的MFR(熔体流动速度)低于PP-g-MAH的;PP-g-GMA质量份为6份时,共混体系的拉伸强度和冲击强度较未增容体系提高了54.8%和21.8%,增强与增韧效果较明显;当PP-g-MAH质量份为6份时,共混体系的拉伸强度提高了52.1%,但冲击强度稍有降低;PP-g-GMA使得r-PET在PP中分布更均匀。     

相容剂对PA6/PP合金性能的影响

分别采用聚丙烯接枝马来酸酐(PP-g-MAH)和硬脂酸(ST)作为相容剂,通过熔融共混法制备了PA6/PP(聚酰胺6/聚丙烯)合金,研究相容剂用量对该合金性能的影响。结果表明,随着相容剂的增加,PA6/PP合金的吸水性和熔体流动速率下降,拉伸强度和缺口冲击强度先增大后减小。当PP-g-MAH和ST用量分别为PA6/PP合金的4.0%(质量分数,下同)和2.0%时,复合材料的综合性能更佳。     

空心玻璃微珠和PP-g-MAH对PP力学性能及结晶性能的影响

通过熔融共混挤出的方法,制备了聚丙烯(PP)/空心玻璃微珠(HGB)和PP/聚丙烯接枝马来酸酐(PP-g-MAH)/HGB复合材料。研究了HGB和PP-g-MAH对复合材料微观结构、力学性能和结晶性的影响。结果表明,PP-g-MAH可提高HGB与PP的相容性;复合材料的拉伸强度和弯曲强度随HGB的增加表现出先增大后减小的趋势,断裂伸长率和冲击韧性逐步下降;PP-g-MAH可进一步提高拉伸强度、弯曲强度和冲击强度。PP-g-MAH的加入促使产生少量β晶,HGB和PP-g-MAH都降低了PP的结晶度和结晶速率。     

增容剂对PP/PA66共混物力学性能和结晶行为的影响

采用熔融共混法制备了聚丙烯(PP)/聚酰胺66(PA66)共混物,研究了聚丙烯接枝马来酸酐(PP-g-MAH)和乙烯-辛烯共聚物接枝马来酸酐(POE-g-MAH)作为增容剂对PP/PA66共混物力学性能和非等温结晶行为的影响。结果表明:PP-g-MAH提高了共混体系的拉伸强度,加入5份POE-g-MAH能显著提高共混物的断裂伸长率;PA66可起到异相成核作用,使PP的结晶峰温度升高;加入PP-g-MAH进一步提高了PP的结晶峰温度;PA66使PP的结晶活化能增大,增容剂的加入则使共混体系中PP的结晶活化能降低。     

增容PP/回收PET共混物的力学性能

采用熔融挤出法制备了聚丙烯(PP)/增容剂/回收聚对苯二甲酸乙二酯(r-PET)共混物,研究了r-PET、不同增容剂和混合增容剂对PP/r-PET共混物力学性能的影响.r-PET提高了PP的拉伸强度、弯曲强度及其模量,但降低了冲击强度;采用马来酸酐接枝聚丙烯(PP-g-MAH)增容,可提高PP/r-PET共混物的拉伸强度、弯曲强度及其模量,但使冲击强度稍有降低;马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)增容或PP-g-MAH/POE-g-MAH混合增容可提高PP/r-PET共混物的冲击强度,且对共混物的拉伸和弯曲强度影响不大.     

Wide-angle X-ray diffraction studies of nylon–ionomer blends

Blends of nylon 6 with poly(acrylic acid) polyacrylamide, poly(ethylene-co-acrylic acid), poly(ethylene-co-vinyl alcohol), poly(acrylamide-co-acrylic acid), and polypropylene were prepared by melt blending. Annealing treatments included treatments in Vacuum, in water, and in 20% formic acid at various temperatures. WAXS (wide-angle X-ray scattering) patterns of melt chips and of undrawn, drawn and textured yarns were obtained. The melt chips of 100% nylon 6 crystallize in the α form while the chips of all the blends exhibit a single diffracton ring. All the blends behave similarly during different annealing treatments. When annealed in 20% formic acid at 102°C, the α structure results. The as-spun fibers of nylon 6 and of the blends with poly(acrylamide-co-acrylic acid) and poly(ethylene-co-vinyl alcohol) exhibit a broad diffraction maximum in the region 2θ = 19–25°. The α content and its purity increase with increasing severity of the annealing treatment. The as-spun fibers of the blend with poly(acrylic acid), on the other hand, exhibit a highly oriented γ structure which is highly resistant to conversion to the α from during the annealing treatments. Only when treated in 20% formic acid at 102° does the pure α form result. The drawn textured yarns of nylon 6 exhibit both the α and the γ forms. However, the γ content of the textured yarns from the blends varies with the type and concentration of the additives. The textured yarns from the blends with low levels (0.125%) of poly(acrylic acid) have a very high α content. It is very unusual that the as-spun fibers with almost pure γ structure, when drawn, produce a structure with a high α content.     

增容作用对PP/PA6原位微纤复合材料形貌及性能的影响

以马来酸酐接枝聚丙烯(PP-g-MAH)为增容剂,采用熔融挤出-热拉伸法制备了聚丙烯(PP)/聚酰胺6(PA6)/PP-g-MAH原位微纤复合材料.研究了复合材料的微观相形态以及结晶、流变和力学性能.结果表明,加入0.5％(质量分数,下同)的PP-g-MAH有利于大长径比PA6微纤的形成;而当PP-g-MAH的含量继续...     

Drawing and ultimate tensile properties of modified polyamide 6 fibers

The drawing and ultimate tensile properties of the modified PA 6 (MPA) fiber specimens prepared at varying drawing temperature were systematically investigated, wherein the MPA resins were prepared by reactive extrusion of PA 6 with the compatibilizer precursor (CP). At any fixed drawing temperature, the achievable draw ratio (D_ra) values of MPA as‐spun fiber specimens increase initially with increasing CP contents, and then approach a maximum value, as their CP contents are close to the 5 wt% optimum value. The maximum D_ra values obtained for MPA as‐spun fiber specimens prepared at the optimum CP content reach another maximum as their drawing temperatures approach the optimum drawing temperature at 120°C. The tensile and birefringence values of PA 6 and MPA fiber specimens improve consistently as their draw ratios increase. Similar to those found for their achievable drawing properties, the ultimate tensile and birefringence values of MPA fiber specimens approach a maximum value, as their CP contents and drawing temperatures approach the 5 wt% and 120°C optimum values, respectively. Investigations including Fourier transform infrared, melt shear viscosity, gel content, thermal and wide angle X‐ray diffraction experiments were performed on the MPA resin and/or fiber specimens to clarify the optimum CP content and possible deformation mechanisms accounting for the interesting drawing, birefringence, and ultimate tensile properties found for the MPA fiber specimens prepared in this study. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

马来酸酐接枝物对PE/PA6共混物相容性的影响

采用熔融共混法制备了PP/PA6/POE-g-MAH和PP/PA6/PP-g-MAH共混物。通过扫描电子显微镜(SEM)、差示扫描量热(DSC)仪分析和力学性能测试研究了增容剂POE-g-MAH和PP-g-MAH对PP/PA6共混物相容性、形态结构和宏观力学性能的影响。结果表明,在PP/PA6共混体系中分别加入POE-g-MAH和PP-g-MAH不仅能显著改善两相界面的相容性,减小分散相的粒径,而且能使共混物的力学性能显著提高。当增容剂的用量为5份时,PP/PA6共混物有较好的综合力学性能。POE-g-MAH和PP-g-MAH增容PP/PA6共混体系非等温结晶行为的研究表明,POE-g-MAH和PP-g-MAH均能促进PA6对PP基体的异相成核作用。     

Factors influencing the formation of elongated morphologies in immiscible polymer blends during melt processing

The morphology of the dispersed phase in immiscible polymer blends plays an important role in the determination of the final physical properties. This paper considers factors that influence the final state of deformation of the dispersed phase, and in particular, the formation of fibers and lamellae. Blends of polyethylene and nylon-6 were extruded by ribbon extrusion at different draw ratios. Prior to single-screw extrusion the materials were blended in a co-rotating twin-screw extruder, and the size of the dispersed phase was studied as a function of the viscosity ratio. As the blends are extruded into ribbons and drawn through the calender rolls, the morphology of the dispersed phase undergoes drastic transformations. The fiber formation is enhanced by increasing the draw ratio. At high draw ratios, long thin fibers are observed. Some biaxial deformation is obtained for the noncompatibilized systems when the extruded materials enter the calender with the maximum closing pressure applied to the rolls. The same effect is observed for the compatibilized systems with lower values of the viscosity ratio. As a general rule, it has been observed that the final dispersed phase deformation is diminished in interfacially compatibilized systems.     

Structure and properties of blend fibers from poly(ethylene terephthalate) and liquid crystalline polymer

The structure and properties of the as-spun fibers of poly(ethylene terephthalate) (PET) blends with a thermotropic liquid crystalline polymer (LCP), Vectra A900, were studied in detail. The DSC results indicate that the LCP component may act as a nucleating agent promoting the crystallization of the PET matrix from the glassy state but which inhibits its crystallization from the melt due to the existence of an LCP supercooled mesophase. The effect of the drawdown ratio on the orientation of the as-spun blend fibers is highly composition-dependent, which is mainly associated with the formation of LCP fibrils during melt spinning. The modulus of the as-spun blend fibers has a significant increase as the content of LCP reaches 10%, while the tensile strength has a slightly decreasing tendency. The mechanical properties of the as-spun blend fibers could be well improved by heat treatment because of a striking increase in the crystallinity of the PET matrix. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 217–224, 1997     

PP-g-（DMC-co-St）增容PP／PVC共混体系的研究

利用合成的多单体接枝物[PP-g-（DMC-co-St）]增容PP／PVC共混体系,研究了其用量对共混物力学性能以及流变性能的影响,并通过扫描电镜（SEM）分析了共混物的亚微观相结构。结果表明：①在试验条件下,共混物熔体具有典型的假塑性流体特征,在PP-g-（DMC-co-St）用量为6份时,熔体的表观黏流活化能和非牛顿指数最大;②PP-g-（DMC-co-St）对PP／PVC共混体系有较好的增容效果,增容后在PP-g-（DMC-co-St）用量为6份时,试样的拉伸强度、缺口冲击强度出现最大值,与扫描电镜照片的分析结果一致。     

Binary blends of nylons with ethylene vinyl alcohol copolymers: Morphological,thermal, rheological,and mechanical behavior

Binary blends of ethylene vinyl alcohol copolymers, containing 62 (EVOH-62) and 71 (EVOH-71) mole percent vinyl alcohols, with nylons (nylon-6, nylon-6/12, and nylon-12) have been prepared from melt mixing in a twin screw compounding machine. Morphological, thermal, rheological, and mechanical properties were determined. EVOH-62/nylon-6 and EVOH-71/nylon-6 blends showed homogeneous phase morphologies in the nylon-6-rich region, and fine phase separations (c.a. 2 × 10^?7 m) in the EVOH-rich region. Melting point depression, positive deviations in viscosity and flexural modulus, and negative deviation in impact strength from the simple additive rule were generally observed. And the results were possibly interpreted in terms of compatibility and increased nylon/EVOH interactions over the nylon/nylon interactions. On the contrary, clean phase separations in large domains were observed from EVOH-71/nylon-6/12 and EVOH-71 /nylon-12 blends. Fibrillation was also obtained from EVOH rich blends. Probably due to the incompatible nature of these blends, yield at low rate of shear and a mechanical property drop were also observed.     

Effects of composition of modified polyamide on barrier properties of polyethylene/modified polyamide blends

A systematic study on the effects of types and contents of compatibilizer precursors (CPs) on degrees of crystallinity (W_c), melt shear viscosities (η_s), and permeation barrier properties of modified polyamides (MPAs) and on their corresponding morphology and barrier properties of bottles blow-molded from polyethylene (PE)/MPA blends is reported. Two alkylcarboxyl-substituted polyolefins were selected as CPs to modify PA and to improve its permeation resistance to xylene by the “reactive extrusion” process. The barrier improvements of MPAs prepared in this study depend significantly on the type and content of CP present in the MPA. A maximum improvement in barrier properties of each MPA series samples were found as the contents of CP reached an “optimum” value. On the other hand, it is interesting to note that bottles blow-molded from PE/MPA series samples exhibited better barrier properties because the MPAs used were associated with better permeation resistance to xylene. The melt shear viscosities of MPAs were found to depend on the type of CP used and increase with increasing CP contents. In contrast, the W_c of MPAs decreased with increasing CP contents. Further analysis of the fracture surfaces of bottles blow-molded from PE/MPA blends also indicated that the morphology of MPA laminas depended on the type of CP present in the MPA, and these MPA laminar structures became clearer as the contents of CPs increased. Possible mechanisms accounting for the interesting behaviors described above are discussed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1531–1540, 1997     

High-modulus fibres of nylon-6 prepared by a dry-spinning method

Nylon-6 filaments with tensile strengths at break up to 1 GPa and initial moduli in the range of 16 to 19 GPa have been produced by dry-spinning of solutions of nylon-6 in cosolvent mixtures of formic acid and chloroform followed by hot-drawing at 200°C–240°C. Tensile strengths and elastic moduli of the nylon-6 fibres were strongly dependent on the draw ratio, on the molecular weight of the polymer, on the polymer concentration in the spinning solution and on concentration of nonsolvent in the spinning solution. At high concentrations of nonsolvent in the spinning solution, the as-spun fibres of nylon-6 were composed of ball-like structural units, formed possibly due to the liquid-liquid phase separation in the polymer/solvent/nonsolvent ternary system. Formation of ball-like structures reduced the ultimate mechanical properties of hot-drawn fibres of nylon-6.