PP/PP-g-MAH/EVOH共混物流变和结晶行为研究

采用马来酸酐接枝聚丙烯(PP-g-MAH)为相容剂,增容聚丙烯/乙烯-乙烯醇共聚物(PP/EVOH)共混体系。利用旋转流变仪研究PP-g-MAH含量对PP/PP-g-MAH/EVOH共混物流变和结晶行为影响。结果表明:随着PP-g-MAH含量的增加,PP/PP-g-MAH/EVOH共混物体系相容性逐渐改善,黏度、储能模量与损耗模量均先增加后减小。此外,随着PP-g-MAH含量的增加,PP/PP-g-MAH/EVOH共混物中PP相的成核温度(T_b)和生长温度(T_c)也逐渐向低温方向偏移,同时PP晶体后期成核速率和晶体长大速率逐渐减小。     

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。     

剪切作用下POE-g-MAH和PP-g-MAH对PA1010/PP共混物的增容作用

采用熔融共混的方法制备了聚酰胺1010/聚丙烯（PA1010/PP）共混物,通过扫描电镜、力学性能和差示扫描量热等方法研究了剪切作用下马来酸酐接枝乙烯-辛烯共聚物（POE-g-MAH）和马来酸酐接枝聚丙烯（PP-g-MAH）对PA1010/PP共混物的增容作用。结果表明,同样条件下,PP-g-MAH增容体系的相区尺寸较小,相界面更模糊,PP相的结晶温度和结晶度明显提高,共混物的拉伸强度和冲击强度均高于非增容体系。而POE-g-MAH增容体系的相区尺寸相对较大,PP相的结晶温度和结晶度明显降低,共混物只有冲击强度明显高于非增容体系,拉伸强度略低于非增容体系。     

PP-g-Si对PP/GF的增容效果研究

制备了硅烷接枝聚丙烯(PP-g-Si),研究了PP-g-Si作为PP/GF体系的界面相容剂对界面结合和力学性能的影响,并与马来酸酐接枝聚丙烯(PP-g-MAH)的增容效果进行了比较。结果表明,PP-g-Si对PP/GF体系有增容作用,PP-g-Si不仅可以改善PP/GF复合体系的拉伸强度,而且可以改善PP/GF复合体系的韧性;PP-g-Si的增容效果优于PP-g-MAH。     

PTT/PP共混物的性能研究

通过熔融共混制备了聚对苯二甲酸丙二酯/聚丙烯(PTT/PP=75/25)及其马来酸酐接枝PP(PP-g-MAH)增容共混物,研究了PTT/PP及其增容共混物的结晶性能、力学性能、流变性能和结晶形态。研究结果表明,PTT与PP共混能提高PP、PTT组分的结晶温度;对于增容共混物,随PP-g-MAH用量的增加,PP和PTT的结晶温度基本不变。加入PP使PTT拉伸强度降低,冲击强度提高;PP-g-MAH增容使共混物的拉伸和冲击强度都提高。增容共混物的熔体粘度明显降低,存在明显的剪切变稀现象,但熔体粘度与PP-g-MAH用量无关。在一定用量范围内,随PP-g-MAH用量的增加,PP分散相的尺寸变小。     

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。     

PP-g-AA在PP复合材料和关混物中的应用进展

本文综述了近十年来国内外关于丙烯酸接枝聚丙烯(PP-g-AA)在填充PP、增强PP和PP共混物中的应用进展。作为大分子相容剂，PP-g-AA能够明显提高PP复合材料和共混物组分间的相容性，增加界面结合力，进而提高材料的综合性能。     

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。     

PP-g-Si对PP／GF的增容作用

制备了硅烷接枝聚丙烯(PP-g-Si)，研究了PP-g-Si作为聚丙烯／玻纤(PP／GF)复合体系的界面相容剂对界面结合和力学性能的影响，并与马来酸酐接枝聚丙烯(PP-g-MAH)的增容效果进行了比较。结果表明，PP-g-Si对PP／GF体系有增容作用，不仅可以改善PP／GF复合体系的拉伸强度，而且可以改善其韧性。硅烷接枝聚丙烯可以降低PP／GF复合体系的最大扭矩。玻纤的加入可以提高聚丙烯的热变形温度，硅烷接枝聚丙烯对PP／GF复合体系的热变形温度有稍微改善。扫描电镜观察表明，玻纤与基体间具有强有力的界面结合，硅烷接枝聚丙烯的增容效果优于马来酸酐接枝聚丙烯。     

双单体接枝物增容PP/EVOH共混物形态结构及性能

采用反应型双螺杆挤出机制备了双单体接枝物聚丙烯（PP）接枝马来酸酐（MAH）和三烯丙基异氰脲酸酯（TAIC）[PP-g-(MAH-co-TAIC)],并以此增容PP/乙烯-乙烯醇共聚物（EVOH）共混物。研究了共混增容体系的相容性、流变性能、结晶性能、力学性能和阻隔性能。红外光谱分析表明, 接枝物加入后,在EVOH的羟基和接枝物的酸酐基团之间发生了反应,体系的相容性因此得以改观;TAIC的加入使PP的接枝率提高了13 %;扫描电子显微镜观察证实,接枝物的加入促进了EVOH和PP之间的界面结合,减小了分散相的尺寸。流变性能测试表明,TAIC的加入抑制了PP的降解;差示扫描量热仪分析表明,接枝物的加入使得PP和EVOH的结晶温度得到了提高。双单体接枝物的共混体系与单一单体接枝物的共混体系相比,对力学性能影响不大,但阻隔性能有所提高,当共单体添加量为0.4份（质量份,下同）时,体系的阻隔性能提高了28 %。     

Interface modification and characterization in three‐component polymer blends

The effect of interface characteristics on the properties of three‐component polymer blends comprising PP/EVOH/mica and PP/EVOH/glass beads (GB) was investigated (polypropylene‐PP, ethylene‐vinylalcohol‐EVOH). The systems selected are based on the binary PP/EVOH immiscible blend representing a semi‐crystalline apolar polymer (PP) and a semi‐crystalline highly polar copolymer (EVOH), where PP serves as the matrix. A series of the binary and three‐component blends with varying compositions was chosen to study the effect of the molding procedure, i.e. compression versus injection molding. The structures observed by SEM analysis consisted of the filler particles engulfed by the EVOH phase, with some of the minor EVOH component dispersed within the PP matrix. The effects of silane treatment (GB/EVOH interface) and compatibilization, using a maleated‐PP compatibilizer (PP/EVOH interface), were studied in relation to the generated structured and properties. The compatibilizer was added in a unique procedure by which the encapsulated GB/EVOH structures were preserved. The characterization methods used included morphology by Scanning Electron Microscopy, thermal properties and crystallization behavior by Differential Scanning Calorimetry, mechanical properties by tensile testing, and dynamic characteristics by Dynamic Mechanical Thermal Analysis. The work has shown that structure‐performance relationships in the three‐component blends can be varied and controlled.     

Influence of the ethylene–(methacrylic acid)–Zn2+ ionomer on the thermal and mechanical properties of blends of poly(propylene) (PP)/ethylene–(vinyl alcohol) copolymer (EVOH)

The thermal and mechanical properties and the morphologies of blends of poly(propylene) (PP) and an ethylene–(vinyl alcohol) copolymer (EVOH) and of blends of PP/EVOH/ethylene–(methacrylic acid)–Zn²⁺ ionomer were studied to establish the influence of the ionomer addition on the compatibilization of PP/EVOH blends and on their properties. The oxygen transmission rate (O₂TR) values of the blends were measured as well. PP and EVOH are initially incompatible as was determined by tensile tests and scanning electronic microscopy. Addition of the ionomer Zn²⁺ led to good compatibility and mechanical behaviour was improved in all blends. The mechanical properties on extruded films were studied for 90/10 and 80/20 w/w PP/EVOH blends compatibilized with 10 % of ionomer Zn²⁺. These experiments have shown that the tensile properties are better than in the injection‐moulded samples. The stretching during the extrusion improved the compatibility of the blends, diminishing the size of EVOH domains and enhancing their distribution in the PP matrix. As was to be expected, the EVOH improved the oxygen permeation of the films, even in compatibilized blends. Copyright © 2004 Society of Chemical Industry     

EVOH／PE-HD共混相容性研究

使用三种功能化改性的聚乙烯作为相容剂改善EVOH／PE-HD共混体系的相容性，研究了共混体系的热性能和力学性能。SEM表明，相容共混体系中形成了高度分散和牢固的界面结合，二甲苯萃取实验和IR分析证实了相容性的改善来自于EVOH与相容剂之间的化学反应。相容共混体系中EVOH作为分散相时其结晶温度明显降低，结晶速度放慢；共混物中两组分的结晶熔点均低于纯组分。这些均可归因于体系更好的相容性以及强烈的界面作用。相容共混体系的力学性能较之简单共混体系得到明显改善，EVOH为分散相时拉伸强度提高幅度较大(50％)，而在PE-HD为分散相时缺口冲击强度的增幅达到30％。     

The effect of interface characteristics on the morphology,rheology and thermal behavior of three‐component polymer alloys

Immiscible polymer blends are interesting multiphase host systems for fillers. Such systems exhibit, within a certain composition limits, either a separate dispersion of the two minor phases or a dispersion of encapsulated filler particles within the minor polymer phase. Both thermodynamic (e.g. interfacial tension) and kinetic (e.g. relative viscosity) considerations determine the morphology developed during the blending process. The effect of interfacial characteristics on the structure‐property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene‐vinyl alcohol copolymer (EVOH) and glass beads (GB), or fibers (GF), was investigated. The system studied was based on a binary PP/EVOH immiscible blend, representing a blend of a semi‐crystalline apolar polymer with a semicrystalline highly polar copolymer. Modification of the interfacial properties was obtained through using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA‐g‐PP) for the PP/EVOH interface. The compatibilizer was added in a procedure aimed to preserves the encapsulated EVOH/glass structure. Blends were prepared by melt extrusion compounding and specimens by injection molding. The morphology was characterized using scanning electron microscopy (SEM) and high resolution SEM (HRSEM), the shear viscosity by capillary rheometry and the thermal behavior using differential scanning calorimetry (DSC). The system studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfaces resulted in unique morphologies. The aminosilane glass surface treatment enhanced the encapsulation in the ternary [PP/EVOH]GB blends, resulting in an encapsulated morphology with no separtely dispersed EVOH particles. The addition of a MA‐g‐PP compatibilizer preserves the encapsulated morphology in the ternary blends with some finely dispersed EVOH particles and enhanced PP/EVOH interphase interactions. The viscosity of the binary and ternary blends was closely related to the blend's morphology and the level of shear rate. The treated glass surfaces showed increased viscosity compared to the cleaned glass surfaces in both GB and GF containing ternary blends. Both EVOH and glass serve as nucleating agents for the PP matrix, affecting its crystallization process but not its crystalline structure. The aminosilane glass surface treatment completely inhibited the EVOH crystallization process in the ternary blend. In summary, the structure of the multicomponent blends studied has a significant effect on their behavior as depicted by the rheological and thermal behavior. The structure‐performance relationships in the three‐component blends can be controlled and varied.     

聚酰胺6／乙烯-乙烯醇无规共聚物共混体系的相容性及性能研究

研究了不同比例乙烯-乙烯醇无规共聚物(EVOH)和聚酰胺6(PA6)共混物的相容性及性能。扫描电子显微镜下观察结果表明二者具有较好的相容性;红外光谱分析和流变实验证实了EVOH与PA6分子间氢键的存在,氢键的作用会随着EVOH含量的增加而增强;阻透性能的测试表明在PA基体中加入EVOH会极大提高基体的阻透性,在EVOH基体中加入少量的PA6对EVOH的阻透性影响很小。     

The development of laminar morphology during extrusion of polymer blends

Studies of the microstructure and permeability of extruded ribbons of polypropylene (PP)/ethylene vinyl alcohol copolymer (EVOH) and polyethylene (PE)/polyamide-6 (PA-6) blends have shown that it is possible to control the flow-induced morphology to generate discontinuous overlapping platelets of EVOH or PA-6 dispersed phase in a PP or HDPE matrix phase. The effects of the following factors on morphology development and blend properties were considered: blending sequence, melt temperature, composition, compatibilizer level, die design, screw type, and cooling conditions. The impact properties and interfacial adhesion of laminar blends of PP and EVOH were improved without diminishing the barrier properties. The oxygen and toluene permeability of extruded samples with EVOH content of 25 vol% resembled values obtained with multilayer systems. Processing conditions had a major influence on the morphology of blends of high density polyethylene and polyamide-6 (HDPE/PA-6), and, under special processing conditions, laminar morphology was obtained in this system. The toluene permeability of extruded ribbons of HDPE/PA-6 blends was in the range obtained with multilayer systems.     

Effect of compatibilizer on the crystallization,rheological, and tensile properties of LDPE/EVOH blends

The effect of the compatibilizer on the crystallization, rheological, and tensile properties of low-density polyethylene (LDPE)/ethylene vinyl alcohol (EVOH) (70/30) blends was investigated. Maleic anhydride-grafted linear low-density polyethylene (LLD-g-MAH) was used as the compatibilizer in various concentrations (from 1 to 12 phr). The interesting effect of compatibilization on the crystallization kinetics of the blends was noted, and the correlation between the morphology and the rheological and tensile properties was also discussed. Morphological analysis showed that the blends exhibited a regular and finer dispersion of the EVOH phase when LLD-g-MAH was added. Nonisothermal crystallization exotherms of the compatibilized LDPE/EVOH blends showed the retarded crystallization of the dispersed EVOH phase, which probably resulted from the constraint effect of the grafted EVOH (EVOH-g-LLD) as well as the size reduction of the EVOH domains. The blends exhibited increased melt viscosity and storage modulus and also enhanced tensile properties with the addition of LLD-g-MAH, which seemed to be attributable to both dispersed particle-size reduction and improved interfacial adhesion. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1245–1256, 1998     

The effect of interface characteristics on the static and dynamic mechanical properties of three‐component polymer alloys

The effect of interfacial characteristics on the structure‐property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene‐vinyl alcohol copolymer (EVOH) and glass beads (GB) or fibers (GF) was investigated. The systems studied were based on a binary PP/EVOH immiscible blend, representing a blend of a semi‐crystalline apolar polymer with a semi‐crystalline highly polar copolymer. The ternary systems studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfacial properties was done using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA‐g‐PP) for the PP/EVOH interface. Both glass fillers increased the dynamic modulus and decreased the damping of the neat polymers and of their binary blends, especially in the rubbery region. GF has a more profound effect on both the modulus and the damping. Glass surface treatments and compatibilization have only a marginal effect on the dynamic mechanical behavior of the ternary blends. Yet, compatibilization shifted the polymers' T_gS to higher temperatures. Both glass fillers increased the elastic modulus of the binary blends, where GF performed better than GB as a reinforcing agent. GF slightly increased the strength of the binary blends while, GB reduced it. Both fillers reduced the ductility of the binary blends. The blends' mechanical properties were related to the morphology and their components' crystallinity. The compatibilizer increases both stiffness and strength and reduces deformability.     

Use of a sodium ionomer as a compatibilizer in polypropylene/high‐barrier ethylene–vinyl alcohol copolymer blends: The processability of the blends and their physical properties

The effect of a sodium ionomer (ion.Na⁺) on the compatibility of polypropylene (PP)/high‐barrier ethylene–vinyl alcohol copolymer (EVOH) blends was studied in terms of the thermal, mechanical, and optical properties and morphology. The rheological behavior, tensile tests, and morphology of the binary blends showed that the miscibility of EVOH with PP was very poor. The miscibility of the polymers improved with the ionomer addition. In general, the ion.Na⁺ concentration did not alter the thermal behavior of the blends, but it did improve the ductility of the injection‐molded specimens. Scanning electron micrographs displayed better adhesion between the PP and EVOH phases in the samples with the ionomer. The mechanical improvement was better in the film samples than in the injection‐molded samples. A 90/10 (w/w) PP/EVOH film with 5% ion.Na⁺ and an 80/20 (w/w) PP/EVOH film with 10% ion.Na⁺ presented better global properties than the other blends studied. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1763–1770, 2004