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。     

Dynamic rheological,morphology and mechanical properties of compatibilized LLDPE/EMA blends

Blends of linear low density polyethylene (LLDPE) and ethylene-co-methyl acrylate (EMA) having 60/40 composition was studied with and without compatibilizing agent. The compatibilizing agent used was maleic anhydride grafted linear low density polyethylene (LLDPE-g-MA). The LLDPE backbones of the compatibilizer are compatible with LLDPE blend component, whereas the maleic anhydride is affinated with carbonyl groups of EMA. The effectiveness of the compatibilizing agent was evaluated using different techniques like mechanical, thermal, scanning electron microscopy and rheological studies. Best compatibilization effect was found in the blend at a loading of 3 wt% of compatibilizer since at this level of compatibilizer complex viscosity, tensile strength, modulus, elongation at break, impact strength was found to be higher. The increase in the melt viscosity, storage modulus and thermal stability of the compatibilized blends indicated enhanced interactions between the discrete LLDPE and EMA phases induced by the functional compatibilizer.     

Comparison of structure and properties of conventional and “high‐crystallinity” isotactic polypropylenes and their blends with metallocene‐catalyzed linear low‐density polyethylene. I. Relationships between rheological behavior and thermal and physical properties

The present study was conducted to compare the structure and properties of conventional and so‐called “high‐crystallinity” (hcr) polypropylene (PP) and to establish characteristic features of the latter that are responsible for its superior thermal and mechanical performance. Moreover, structure–properties relationships of hcr PP blends with metallocene‐catalyzed, linear low‐density polyethylene (mLLDPE) were compared with those of conventional PP/mLLDPE blends. In Part 1, relationships between rheological behavior (viscosity and melt density) and thermal (transition temperatures and level of crystallinity) and mechanical properties (impact strength and Young's modulus) were analyzed with reference to composition. The rheological and MDSC tests showed that both types of the blends were miscible at the processing temperatures, whereas immiscible in the solid state and in vicinity of the PP melting point. It was found that the improved mechanical properties and the extraordinary high crystallization temperature of hcr PP (and, correspondingly, hcr PP/mLLDPE blends) are not due to the assumed high level of crystallinity but due to alteration of internal structure of this polypropylene. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1591–1599, 2000     

Rheological properties,crystallization, and morphology of compatibilized blends of isotactic polypropylene and polyamide

Blends of isotactic polypropylene (iPP) with the polyamide nylon-6 (N6), prepared by extrusion, were studied with a composition of up to 30% by weight polyamide. In the case of a 70/30 iPP/N6 blend, the influence of a compatibilizing agent based on polypropylene functionalized with maleic anhydride (PP-g-MA), with compositions of 1, 3, 5, and 10% by weight in polypropylene, was followed. The influence of the concentration of N6 and the compatibilizing agent on the rheological and thermal properties, and the morphology of the blends, was analyzed by monitoring the melt viscosity at different shear rates, differential scanning calorimetry, and polarized light microscopy. Vibrational spectroscopy was used to characterize the blends and to study the effect of the compatibilizing agent. The viscosity—composition curves for the iPP/N6 blends, in the composition and shear rate ranges analyzed, show a negative deviation from the additive rule, while the opposite trend is observed for the blends compatibilized with PP-g-MA. Important variations in the spectroscopic behavior was observed between compatibilized and noncompatibilized blends, which varied as a function of the compatibilizing agent concentration. The crystallization rates of iPP in the iPP/N6 blends, under both dynamic and isothermal conditions, are much greater than are those observed for pure iPP and are directly related to the nucleating activity of the polyamide. This effect is much smaller in the presence of the compatibilizing agent. The isothermal crystallization of the polyamide N6 in compatibilized blends is affected by the presence of iPP, reducing the crystallization rate due to the diluent effect of the polypropylene. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2665–2677, 1997     

PP—g —HMA增容尼龙6／聚丙烯共混物结构与性能研究

采用固相力化学方法制备的聚丙烯接枝羟甲基丙烯酰胺作增容剂,制备了尼龙6／聚丙烯共混物,通过SEM、DSC、流变性能测试和力学性能测试研究了共混物的结构、流变性能和力学性能。 结果表明,当尼龙6体积分数为80％时,增容共混体系中冲击强度出现峰值,达到77J／m,分散相尺寸变小,增容共混体系熔融粘度增加。通过Molau实验和FT－IR分析对增容机理作了初步探讨。     

Crystallization behavior and mechanical properties of polypropylene random copolymer/poly(ethylene‐octene) blends

New polymer blends of polypropylene random copolymer (PP‐R) and poly(ethylene‐octene) (POE) were prepared by melt‐blending process using a corotating twin‐screw extruder. The POE content was varied up to 35%. The toughening efficiency of POE for PP‐R was evaluated by the mechanical properties of the resulted PP‐R/POE blends. The crystallization behavior and morphology of the blends were also studied. Results show that POE acts as nucleation agent to induce the crystallization of PP‐R matrix at higher crystallization temperature. Super‐toughened PP‐R/POE blends (Izod impact strength more than 500 J/m) can be readily achieved with only 10 wt % of POE. The high toughness of PP‐R/POE is attributed to cavitation and shear yielding of matrix PP‐R, as revealed by the morphology studies. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

增容剂对PP/回收PET共混物性能的影响

采用熔融共混的方法,制备了聚丙烯(PP)/回收聚对苯二甲酸乙二酯(r-PET)共混物,研究了增容剂甲基丙烯酸缩水甘油酯接枝聚丙烯(PP-g-GMA)对共混物力学性能、热稳定性的影响。结果表明:增容剂的加入能提高共混物的拉伸强度和拉伸模量;加入增容剂能显著提高共混物的热分解温度,增容剂使r-PET的熔点降低;增容剂对PP的结晶性能影响与熔融温度有关。     

Study on compatibilization of polypropylene-liquid crystalline polymer blends

The mechanical properties, melt rheology, and morphology of binary blends comprised of two polypropylene (PP) grades and two liquid crystalline polymers (LCP) have been studied. Compatibilization with polypropylene grafted with maleic anhydride (PP-g-MAH) has been attempted. A moderate increase in the tensile moduli and no enhancements in tensile strength have been revealed. Those findings have been attributed to the morphology of the blends, which is predominantly of the disperse mode. LCP fibers responsible for mechanical reinforcement were only exceptionally evidenced. Discussion of PP-LCP interfacial characteristics with respect to mechanical properties-morphology interrelations allowed evaluation of the compatibilizing efficiency of PP-g-MAH. Factors important for successful reinforcement of PP with LCP have been specified. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 969–980, 1997     

Carboxylation of polypropylene by reactive extrusion with functionalized peroxides for use as a compatibilizer in polypropylene/polyamide-6,6 blends

Variable quantities of functionalized peroxides bearing carboxylic acid groups were reacted with polypropylene (PP) in a twin-screw extruder. Systematic variations in the molecular structure of the peroxides were found to significantly affect the grafting efficiency of the carboxylic acid group onto the PP backbone, as well as affect the polymer degradation process. This behavior was attributed to the relative reactivities of the different free radicals generated by thermal decomposition of the peroxides. Furthermore, the functionalized polypropylene (f-PP) was investigated as a compatibilizing additive for 80/20 PP/PA-6,6 (polyamide 6,6) blends. With incorporation of the f-PP into the blends, differential scanning calorimetry (DSC) showed an 80°C decrease in the PA-6,6 crystallization temperature. A near linear increase in the impact strength of the blends was observed with f-PP incorporations up to 30% of the PP phase. Moreover, blends containing 30% f-PP demostrated impact properties approaching that of pure PA-6,6.     

Rheological properties,tensile properties,and morphology of PP/EPDM/lonomer ternary blends

The rheological and tensile properties and the morphology of polypropylene (PP)/ethylenepropylene-diene terpolymer(EPDM)/ionomer ternary blends were investigated, using a rheometric dynamic spectrometer (RDS), a dynamic mechanical thermal analyzer (DMTA), a tensile tester, and a scanning electron microscope (SEM). Two kinds of poly(ethylene-co-methacrylic acid) (EMA) ionomers, neutralized with different metal ions (Na⁺ and Zn⁺⁺), were used. Blends were melt-mixed, using a laboratory internal mixer at 190°C. The composition of PP and EPDM was fixed at 50/50 by wt % and the EMA ionomer contents were varied from 5 to 20 wt %, based on the total amount of PP and EPDM. It was found that the ternary blends, containing Na-neutralized ionomer, showed considerably different rheological properties and morphology as compared to the PP/EPDM binary blends, due to the compatibilizing effect of the ionomer for PP and EPDM, while the ternary blends, containing the Zn-neutralized ionomer, did not. The compatibilizing effect was most prominent at 5 wt % ionomer concentration. © 1994 John Wiley & Sons, Inc.     

Rheological study of recycled polypropylene–starch blends

Blends of recycled polypropylene (PP) and starch (S) with the compositions polypropylene 83 wt%–starch 17 wt% (PP83/S17) (blend 1a), polypropylene 68.8 wt%–starch 31.2 wt% (PP 68.8/S 31.2) (blend 2a) and polypropylene 89.5 wt%–starch 10.5 wt% (PP 89.5/S 10.5) (blend 3a) were synthesized. Maleated polypropylene (MAPP) was used as a compatibilizer. The compositions of the compatibilized blends were PP73/S15/MAPP12 (blend 1b), PP55/S25/MAPP20 (blend 2b) and PP85/S10/MAPP5 (blend 3b). The occurrence of a reaction between MAPP and starch was studied using Fourier transform infrared analysis. Thermal and rheological properties such as the complex viscosity, storage and loss modulus of the blends with a compatibilizer were found to be higher than those of the blends without a compatibilizer. The compatibilized and uncompatibilized blends, as well as recycled PP, were characterized using differential scanning calorimetry, thermogravimetric analysis and cone-and-plate rheometry. The storage and loss modulus values of blend 3b were observed to be the best. The best compatibilizing effect was exhibited by blend 3b at a loading of 5 wt% MAPP because this compatibilizer content yielded the highest complex viscosity and visco-elastic behavior. The presence of a functional compatibilizer enhanced the interactions between starch and recycled PP, which was confirmed by a rise in the melt viscosity, storage modulus and thermal stability. These blends were also characterized in terms of their water uptake by performing water absorption tests. Blend 2b containing 20 % MAPP was observed to absorb the maximum amount of water at 25 °C.     

Melt Rheological and Impact Properties of Thermally Stable PP/mLLDPE Blends

Effect of the heat stabilizer on the melt rheological properties of the blends of polypropylene (PP) with mLLDPE (mettalocene linear low density polyethylene), after thermal degradation in an air oven, was studied. Study carried out is presented to describe the effect of blending ratio and presence of stabilizer on shear stress, shear rate, melt viscosity and melt elasticity parameters. In general, blending of PP with mLLDPE results in an increased viscosity. The viscosity of PP abruptly decreases after the thermal degradation. Interestingly the melt viscosity PP/mLLDPE blend does not show such a marked decrease. This shows that mLLDPE not only acts as an impact modifier but also acts as a thermal stabilizer. The presence of stabilizer in both materials has not shown much difference in melt viscosity thereby suggesting adequate stabilization of the blend system.     

Preparation and Properties of PB-1/PP Blends

Crystallization behavior, dynamic mechanical properties, mechanical properties and rheological properties of isotactic polybutene-1/polypropylene (PB-1/PP) blends prepared by melt-blending the two components through Brabender extruder were mainly studied via POM, DSC, DMA, capillary rheometer and so on, respectively. The results indicated that after adding PP in PB-1: size of the spherical crystal and degree of crystallization of PB-1 in the blends decreased, its melt temperature and crystallization temperature unchanged; tensile property of the blends was decreased, but impact and flexural properties were improved; change of the melt viscosity of the blends with the shear rate was more sensitive than pure PB-1.     

不同促进剂对PP/PP-g-MAH/脱硫胶粉共混物性能影响

选用促进剂N-环己基-2-苯并噻唑次磺酰胺(CZ)、四甲基秋兰姆(TMTD)和N-叔丁基-2-苯并噻唑次磺酰胺(NZ)作为脱硫再生剂,分别对废旧胶粉进行改性,制备脱硫再生胶粉,然后制备聚丙烯(PP)/马来酸酐接枝PP(PP-g-MAH)/脱硫胶粉共混物,研究共混物力学性能、流动性能、断面形貌、流变性能和热性能的影响.结...     

Effect of SEPS as a novel compatibilizer on the properties and morphology of PP/PC/POE blends

A novel macromolecular compatibilizer, styrene-ethylene-propylene-styrene (SEPS) with high content of styrene, was investigated for the purpose of improving the compatibility of PP (polypropylene)/PC (polycarbonate)/POE (ethylene-octene copolymer) blends. SEPS shows a remarkable compatibilizing effect since it has a particular structure with the EP-compatible aliphatic segments, which is well miscible with the nonpolar PP and olefinic elastomer POE domains, and S-chain segments which exhibit strong affinity with PC because of the similar molecular structure. Its compatibilizing effect was examined in terms of the mechanical, morphological, and thermal properties. The compatibilized PP-based blends represent remarkable improvement in impact strength and balanced tensile strength. When 5 wt % SEPS was added to PP/PC/POE blends (20 wt % POE), the impact strength of the blends was enhanced from 24 to 43 kJ/m² without obvious drop in the tensile strength. Their morphologies show a decreasing and much more homogeneous size of dispersed PC and POE particles through addition of SEPS, and the fracture surface morphologies change from irregular mosaic to the mix of mosaic and striation, and finally the regularly distant striation. The special morphology structure that resulted from the effect of the compatibilizer could be a key for enhancement of toughness and balanced rigidity of the blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Melt grafting of vinyltrimethoxysilane and water crosslinking of polypropylene/ethylene-propylene diene terpolymer blends

The melt grafting of vinyltrimethoxysilane (VTMS) onto polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM) blends was studied. The effect of VTMS, EPDM and initiator concentrations on mechanical properties, melt flow index (MFI) and gel content of the modified PP/EPDM samples were investigated. The influence of coagents, i.e. styrene and trimethylolpropane trimethacrylate was also studied. Scanning electron microscopy (SEM) was used to observe the fractured surface of PP/EPDM and the modified PP/EPDM blends. The VTMS grafting reaction was in situ monitored using differential scanning calorimetry (DSC). Moreover, the thermal and crystallization behavior of VTMS-crosslinked PP/EPDM blends were studied by thermogravimetric analysis (TG) and DSC, respectively. It had been found that the thermal stability of VTMS-crosslinked PP/EPDM was improved. DSC measurements showed that the grafting reaction occurs from 170 to 220 °C and the crystallization temperatures increased compared with those of the untreated PP/EPDM.     

PP／RPS反应性共混研究

用IR及DSC研究了（侧基含有过氧键的聚苯乙烯）与PP之间的反应,考察了反应温度、苯乙烯单体等对共混过程的影响。结果表明：RPS/PP共混体系中,PP降解严重,而PP/RPS/Rt（苯乙烯）共混体系可有效地抑制降解,反应生成的PP-g-PS对PP/PS合金具有增容作用,提高了合金的力学性能。     

Relationship between branch length and the compatibilizing effect of polypropylene‐g‐polystyrene graft copolymer on polypropylene/polystyrene blends

Three polypropylene‐g‐polystyrene (PP‐g‐PS) graft copolymers with the same branch density but different branch lengths were evaluated as compatibilizing agents for PP/PS blends. The morphological and rheological results revealed that the addition of PP‐g‐PS graft copolymers significantly reduced the PS particle size and enhanced the interfacial adhesion between PP and PS phases. Furthermore, it is verified that the branch length of PP‐g‐PS graft copolymer had opposite effects on its compatibilizing effect: on one hand, increasing the branch length could improve the compatibilizing effect of graft copolymer on PP/PS blends, demonstrated by the reduction of PS particle size and the enhancement of interfacial adhesion; on the other hand, increasing the branch length would increase the melt viscosity of PP‐g‐PS graft copolymer, which prevented it from migrating effectively to the interface of blend components. Additionally, the crystallization and melting behaviors of PP and PP/PS blends were compared. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40126.     

Binary and ternary blends of recycled high‐density polyethylene containing polypropylenes

Binary and ternary blends of the high viscosity recycled high‐density polyethylene (reHDPE) from milk bottles, containing either homopolymer polypropylene (PP) or copolymer polypropylene (coPP), were developed in an effort to reduce viscosity and encourage ease of processing by injection molding, without a significant loss in mechanical properties. A grade of PP and a grade of coPP that had crystallization temperatures close to and slightly lower than that of reHDPE were chosen for blending in order to obtain simultaneous crystallization of the reHDPE and (co)PP phases. The resulting reHDPE/(co)PP blends (reHDPE wt% = 77) generally showed very good mechanical properties and, in particular, sufficiently high impact strength while engendering considerably lower viscosity than reHDPE. The PP was more useful at very high and low shear rates whereas the coPP was the most efficient in the mid‐range of shear rates (10² – 10³ sec^?1). Good impact resistance shown by the reHDPE/(co)PP blends was attributed in part to the fine dispersion of (co)PP phase, possible involvement of a portion of the polymers in a co‐continuous structure and simultaneous crystallization of the components. Ternary blends of reHDPE (reHDPE wt% = 77), PP and low‐density polyethylene (LDPE) showed good mechanical performance, although they were more viscous than (co)PP blends. In the ternary blends, co‐crystallization of reHDPE and LDPE phases was preserved (1).     

Studies on the engineering properties of LCP‐Vectra B 950/PP blends with the variations of EAA content

Polypropylene (PP) was melt blended with Vectra B‐950 [a thermotropic liquid crystalline polymer (LCP)], in a single screw extruder in presence of different doses of ethylene acrylic acid (EAA) copolymer, as modifier. The effect of incorporation in different proportions of EAA at a fixed dose of 5% LCP, on mechanical, thermal, morphological, and rheological properties of such blends was studied and the same were compared with that of pure PP and amongst themselves. Mechanical analysis (tensile properties) of the prepared blends exhibited improvements in ultimate tensile strength (UTS), modulus, toughness, hardness, and impact strength of PP matrix with the incorporation of EAA. The improvement in mechanical properties is associated with the formation of LCP fibrils as evidenced by scanning electron microscopy (SEM). A strong interaction through H‐bonding between the segments of Vectra B‐950 and EAA was established by FTIR study. Differential scanning calorimetry (DSC) studies indicated substantial increase in melting point of the blends, and thermogravimetric analysis (TGA) showed that the thermal stability of PP was improved with the addition of LCP and EAA. Rheological properties showed that LCP and EAA drop down the melt viscosity of PP and thus facilitate processibility of blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011