The effect of composition on morphological,thermal, and mechanical properties of polypropylene/nylon-6/polypropylene-g-butyl acrylate blends

The effect of concentration of polypropylene grafted with butyl acrylate (PP-g-BA) compatibilizer on thermal, morphological, and mechanical properties of polypropylene/nylon-6 blends has been studied. It was observed that blends with 4.8 wt% concentration of PP-g-BA exhibited superior mechanical and morphological properties at all the compositions of PP/Ny-6. Attempts were made to correlate the experimental data for tensile modulus and strength with existing mathematical models.     

Dynamic mechanical properties of polypropylene–polyamide blends: Effect of compatibilization

The influence of compatibilization on the dynamic mechanical properties of polypropylene (PP) binary blends with polyamide-11 (PA) has been investigated. In the blends an acrylic acid functionized PP was used as a blend component and compared with nonfunctionized PP over the who concentration range. The results demonstrate that the use of the functionized PP instead of the unmodified one produced blends with different dynamic mechanical properties due to adhesion enhancement between the two phases. The storage moduli E′ of the compatibilized blends vary nearly linearly as a function of composition over a broad temperature region, whereas those of the noncompatibilized ones deviate greatly from linearity, specially at about 50/50 ratio, at which a minimum exists at about room temperature. While the dynamic testing gives no evidence for the variation in the glassy transition temperatures (peak maxima) of the components (PP and PA) in the two types of blends, both the loss modulus (E″) and the loss factor (tan δ) data indicate that the compatibilized blends differ from the noncompatibilized ones mainly in the glassy transition (βrelaxation) process of the PA phase, suggesting that the compatibilization of the blends seems to influence the PA phase more than the PP phase included. But, for the β-relaxation behavior of the PA in the modified blends, the tan δ spectrum shows a more complex pattern than does the E″. These results are discussed in terms of the morphological texture of the blends and possible chemical or physical interactions between the two consituent polymers.     

Mechanical characterization of toughened polyamide‐6 blends with metallocene copolymers

The effectiveness as impact modifier of two in situ maleated metallocene copolymers, a metallocene polyethylene, (mPE1) and a metallocene ethylene‐propylene (mEPDM) and three commercial maleated copolymers (mPE2‐g‐MA, EPDM‐g‐MA, and mEPR‐g‐MA) were studied in binary and ternary blends carried out in an intermeshing corotating twin‐screw extruder with polyamide‐6 (PA) as matrix (80 wt %). Also, the effects of the grafting degree, viscosity ratio, and crystallinity of the dispersed phases on the morphological and mechanical properties of the blends were investigated. A significant improvement of the compatibility of these grafted copolymers with PA6 was shown by FTIR spectroscopy, capillary rheometry, and scanning electron microscopy (SEM) in all reactive blends. The tensile strength values of the mEPR‐g‐MA/PA2 binary blend showed the highest strain hardening. The results obtained in this work indicated that the effectiveness of the grafted copolymers as impact modifier depends on the morphology of the blends and a combination of tensile properties of the blend components such as Young's modulus, Poisson ratio, and break stress. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermal and mechanical behavior of polyamide 6/polyamide 6I/6T blends

The thermal and mechanical properties of blends, obtained by mixing polyamide 6 (PA6) and an amorphous aromatic copolyamide G21 (ISO nomenclature PA 6I/6T), were investigated by differential scanning calorimetry, dynamic mechanical analysis, and mechanical tensile tests. Quenched blends show a single glass transition temperature; the T_g-composition trend was interpreted by means of the Gordon–Taylor equation. The half-time of crystal-lization decreases by increasing the G21 content and this indicates a depression of the overall crystallization rate. A small decrease in the equilibrium melting temperature of PA6 in the blends was observed; this finding suggests that the interaction parameter in PA6/G21 blends is probably very small. The dynamic mechanical analysis of crystallized blends suggests the presence of a homogeneous amorphous phase even if the crystallization of PA6 occurred. The tensile mechanical properties reveal that G21 acts as stiffener of PA6. The collected experimental data suggest that PA6 and G21 are miscible in the composition range investigated. © 1996 John Wiley & Sons, Inc.     

Influence of properties and morphology of elastomeric phase on the behavior of ternary reactive blends of polyamide 6/rigid polymer/elastomer

A ternary blend of the PA6 matrix with a finely dispersed rigid polymer and elastomer is a system with well‐balanced mechanical properties. Its micromechanical behavior, especially that of the elastomer phase, apparently differs from corresponding binary mixtures. This study shows the influence of the elastomer type, modulus, and reactivity on the behavior of ternary blends in comparison with analogous binary PA6/elastomer combinations. The presence of rigid reactive poly(styrene‐co‐maleic anhydride) (SMA) enhanced the properties of all the systems studied. For nonreactive elastomers, the dominant effect was refinement of their size due to enhanced viscosity, whereas for functionalized low‐modulus elastomers, the very good balance of properties was due to synergistic influences of both finely dispersed phases. Of interest is the enhanced toughness of ternary blends also for more rigid elastomers having a low toughening efficiency in binary blends. An appropriate addition of rigid SMA together with an elastomer enhances the energy absorption of the matrix, probably without cavitation of very small elastomer particles. Of importance also is the simultaneous strain‐hardening effect of deformed rigid particles. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3647–3651, 2003     

Relation of chain constitution with phase structure in blends: compatibility of two phases in blends of polyamide with low‐density polyethylene and its ionomers

Pressed films of binary blends (polyamide with low‐density polyethylene or Surlyn) and ternary (polyamide with low‐density polyethylene and Surlyn or a graft‐copolymer of acrylic acid onto low‐density polyethylene) were examined by dynamic mechanical analysis, thermally stimulated current, and small‐angle X‐ray scattering. The variation of the glass transition temperature for two phases in the blends was studied by dynamic mechanical analysis and thermally stimulated current. X‐ray scattering from the relation of the phases was analyzed using Porod's law and led to values of the interface layer in the blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 488–494, 2000     

Processability,property, and morphology of biodegradable blends of poly(propylene carbonate) and poly(ethylene‐co‐vinyl alcohol)

Biodegradable blends of poly(propylene carbonate) (PPC) and poly(ethylene‐co‐vinyl alcohol) (EVOH) were melt compounded in a batch mixer followed by compression molding. The processability, mechanical properties, thermal behavior, and morphologies of the blends were investigated with torque rheometer, Fourier transform infrared spectroscopy, tensile tests, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. Torque rheometry indicated good interfacial miscibility between PPC and EVOH phases, and then fourier transform infrared spectroscopy spectra demonstrated that a certain extent of hydrogen‐bonding interactions between PPC and EVOH matrix in the blends. A study of the mechanical properties and thermal behavior showed that the EVOH incorporation can significantly enhance the tensile strength, thermal stability, and crystallinity of the blends. Moreover, dynamic mechanical analysis and differential scanning calorimetry both revealed that PPC and EVOH were compatible to some extent. Further, scanning electron microscopic examination also revealed the good interfacial adhesion between EVOH and PPC phases. POLYM. ENG. SCI., 47:174–180, 2007. © 2007 Society of Plastics Engineers     

Dynamic mechanical behavior of mPE/mEP blends: experimental and prediction

Metallocene-catalyzed polyethylene (mPE)/metallocene-catalyzed ethylene–propylene copolymer (mEP) blends were prepared with a mixing apparatus. The morphology of the blends was observed by scanning electron microscopy and the dynamic mechanical behavior of the blends was systematically investigated. Mean-field theories developed by Kerner were applied to these binary blends of different compositions. The Kerner’s model calculations were compared with the experimental dynamic mechanical properties of the blends and their morphological characterizations. The results showed that Kerner’s model can reasonably predict the viscoelasticity of mPE/mEP blends with different compositions. In addition, the morphological structure of the blends can be estimated via comparing the predicted dynamic mechanical behavior with the experimental data.     

Mechanical Properties and Thermooxidative Aging of a Ternary Blend,Pvc/Enr/Nbr,Compared with the Binary Blends of Pvc

In the quest to improve the thermooxidative aging of the poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blend, nitrile rubber (NBR) was incorporated into the blend to yield a ternary blend of PVC/ENR/NBR. A Brabender Plasticorder with a mixing attachment was used to perform the melt mixing at 150°C and 50 rpm followed by compression molding. The mechanical properties, dynamic mechanical properties, and thermooxidative aging behavior of the ternary blend were compared with those of the binary blends (i.e., PVC/ENR and PVC/NBR). It was found that the ternary blend exhibits mechanical properties which are superior to those of PVC/ENR. A single glass transition temperature (T _g) obtained from dynamic mechanical analysis coupled with synergism in the modulus and some other mechanical properties indicate that PVC, ENR, and NBR form a single phase (miscible system) in the ternary blend. Di-2-ethyl hexylphthalate (DOP) plasti-cizer improves the aging resistance of the blends generally, whereas the presence of CaCO₃ as a filler only imparts minor influences on the properties and aging resistance of the blends.     

Effects of compatibilization of oxidized polypropylene on PP blends of PP/PA6 and PP/talc

The influence of compatibilization on the dynamic mechanical properties of polypropylene (PP) binary blends with polyamide‐6 (PA6), Talc, and oxidized PP (OPP) was investigated. The oxidation of PP homopolymer was performed in a internal mixer by using air as a oxidizing agent (under atmospheric pressure) and dodecanol‐1 as an accelerator at 180°C for 6½ h [Abdouss, M.; Sharifi‐Sanjani, N.; Bataille, P. J Appl Polym Sci 1999, 36, 10]. In the blends, OPP was used as a blend component and compared with PP over the whole concentration range. Pressed film blends of PP/OPP, PP/OPP/Talc, and PP/OPP/PA6 were examined by dynamic mechanical analyzer, thermal gravimetry analysis, and scanning electron microscopy. Mechanical properties such as tensile strength, modulus of elasticity, elongation, melt flow index, and hardness of the blends were measured. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2871–2883, 2004     

SEBS/PPy.DBSA blends: Preparation and evaluation of electromechanical and dynamic mechanical properties

In this study, the electromechanical and dynamic mechanical properties of electrically conducting polymer blends were investigated. The blends were comprised poly(styrene‐b‐butylene‐ran‐ethylene‐b‐styrene) (SEBS) containing polypyrrole doped with dodecylbenzenesulfonic acid (PPy.DBSA). The two types of PPy.DBSA (with and without an excess of DBSA) were blended with SEBS through the solution casting method at room temperature. The dynamic mechanical characterization of the SEBS/PPy.DBSA blends demonstrated that the use of PPy.DBSA with and without free DBSA molecules results in different degrees of interaction with the two phases of the SEBS copolymer matrix. The changes in the electrical conductivity of the blends during repeated pressure loading/unloading were investigated. The conducting SEBS/PPy.DBSA polymer blends exhibited an increase in the electrical conductivity on pressure loading and underwent a corresponding decrease on unloading. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effects of extensional flow on properties of polyamide‐66/poly(2,6‐dimethyl‐1,4‐phenylene oxide) blends: A study of morphology,mechanical properties,and rheology

In this study, polyamide‐66/poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PA66/PPO) blends with high viscosity ratio were processed by a self‐designed triangle‐arrayed triple‐screw extruder (TTSE, which simulates extensional flow) and a commercial twin‐screw extruder (TSE), respectively. Furthermore, in order to improve the mechanical properties of the immiscible PA66/PPO blends, PPO‐grafted maleic anhydride (PPO‐g‐MA) and styrene–ethylene–butylene–styrene (SEBS) block copolymer were used. The mechanical properties, phase morphology, and rheological properties of both binary PA66/PPO blends and toughened PA66/PPO/PPO‐g‐MA blends were comprehensively investigated to compare the above mentioned two processing method. Samples processed with TTSE exhibited better mechanical properties than the TSE‐processed blends. The morphologies of the blends were examined by scanning electron microscopy, exhibiting smaller particles sizes and narrower particle size distributions, which were attributed to the significant effects of extensional flow in TTSE. The toughening mechanism of compatibilized blends was investigated through morphology analysis, dynamic mechanical, and rhelogical analysis. Thus, TTSE with an extensional effect was proved to be efficient in the blending of high viscosity ratio polymers. POLYM. ENG. SCI., 57:1090–1098, 2017. © 2016 Society of Plastics Engineers     

Mechanical properties,oil resistance,and thermal aging properties in chlorinated polyethylene/natural rubber blends

The use of natural rubber (NR) for partly substituting elastomeric chlorinated polyethylene (CPE) was determined. Mechanical and thermal aging properties as well as oil resistance of the blends were also investigated. The amount of NR in blends significantly affected the properties of the blends. The blends with NR content up to 50 wt % possessed similar tensile strength to that of pure CPE even after oil immersion or thermal aging. Modulus and hardness of the blends appeared to decrease progressively with increasing NR content. These properties also decreased in blends after thermal aging. After oil immersion, hardness decreased significantly for the blends with high NR content, whereas no change in modulus was observed. The dynamic mechanical properties were determined by dynamic mechanical thermal analysis. NR and CPE showed damping peaks at about ?40 and 4 °c, respectively; these values correlate with the glass‐transition temperatures (T_g) of NR and CPE, respectively. The shift in the T_g values was observed after blending, suggesting an interfacial interaction between the two phases probably caused by the co‐vulcanization in CPE/NR blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 22–28, 2002; DOI 10.1002/app.10171     

Mechanical and thermal properties of poly(butylene succinate)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) biodegradable blends

Biodegradable polymer blends of poly(butylene succinate) (PBS) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) were prepared with different compositions. The mechanical properties of the blends were studied through tensile testing and dynamic mechanical thermal analysis. The dependence of the elastic modulus and strength data on the blend composition was modeled on the basis of the equivalent box model. The fitting parameters indicated complete immiscibility between PBS and PHBV and a moderate adhesion level between them. The immiscibility of the parent phases was also evidenced by scanning electron observation of the prepared blends. The thermal properties of the blends were studied through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results showed an enhancement of the crystallization behavior of PBS after it was blended with PHBV, whereas the thermal stability of PBS was reduced in the blends, as shown by the TGA thermograms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42815.     

Influence of phase modifiers on morphology and properties of thermoplastic elastomers prepared from ethylene propylene diene rubber and isotactic polypropylene

A series of thermoplastic elastomers (TPEs) were prepared from a binary blend of ethylene propylene diene rubber (EPDM) and isotactic polypropylene (iPP) using different types of phase modifiers. The influence of sulphonated EPDM, maleated EPDM, styrene‐ethylene‐co‐butylene‐styrene block copolymer, maleated PP, and acrylated PP as phase modifiers showed improved physico‐mechanical properties (like maximum stress, elongation at break, moduli, and tension set). Scanning electron and atomic force microscopy studies revealed better morphologies obtained with these phase modified EPDM‐iPP blends. The dependence of the phase modifier type and concentration was optimized with respect to the improvement in physical properties and morphology of the blends. Physical properties, dynamic mechanical properties, and morphology of these blends were explained with the help of interaction parameter, melt viscosity, and crystallinity of the blends. Theoretical modeling showed that Kerner, Ishai‐Cohen, and Paul models predicted the right morphology–property correlation for the prepared TPEs. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.     

Influence of chemical and mechanical compatibilization on structure and properties of polyethylene/polyamide blends

LDPE/PA6 binary blends and LDPE/PA6/compatibilizer ternary blends were prepared in a Brabender extruder, equipped with a prototype static mixer. Compatibility of the components was estimated by rheological properties (viscosity and a melt flow index), and observations of the structure were made with the help of scanning electron microscopy and tensile strength. It was found that the blends' structure and properties are dependent on the recipe content of the polymer blends and the conditions of their manufacturing. Uniformity of the blends of the thermodynamically immiscible polymers was improved by using a prototype static mixer giving mechanical compatibilization and a compatibilizer giving chemical compatibilization. LDPE grafted with a maleic anhydride (LDPE-g-MAH) was used as a compatibilizer. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 719–727, 1998     

Impact-modified blends of compatibilized polyamide-6 with liquid crystalline copolyester

Compatibilized blends of polyamide-6 (PA6) and thermotropic liquid crystalline polymer (LCP) modified with various high-impact polypropylene (HIPP) contents were injection-molded. These blends were compatibilized with maleic anhydride-grafted polypropylene (MAP). The effects of impact modification on the morphology, impact, static, and dynamic mechanical properties were investigated. The results showed that the HIPP addition leads to an improvement of the Izod impact strength of the blends significantly while it reduced the tensile strength and stiffness properties. An attempt was made to correlate the structure of the PA6(MAP)/HIPP/LCP blends from the scanning electron microscopic observations with the measured mechanical properties. This work provides a way to produce a tough in situ composite. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1611–1619, 1998     

Synthesis and properties of reactively compatibilized polyester and polyamide blends

The functionalization of poly(butylene terephthalate) (PBT) has been accomplished in a twin screw extruder by grafting maleic anhydride (MA) using a free radical polymerization technique. The resulting PBT‐g‐MA was successfully used as a compatibilizer for the binary blends of polyester (PBT) and polyamide (PA66). Enhanced mechanical properties were achieved for the blend containing a small amount (as low as 2.5 %) of PBT‐g‐MA compared to the binary blend of unmodified PBT with PA66. Loss and storage moduli for blends containing compatibilizer were higher than those of uncompatibilized blends or their respective polymers. The grafting and compatibilization reactions were confirmed using FTIR and ¹³C NMR spectroscopy. The properties of these blends were studied in detail by varying the amount of compatibilizer, and the improved mechanical behaviour was correlated with the morphology with the help of scanning electron microscopy. Morphology studies also revealed the interfacial interaction in the blend containing grafted PBT. The improvement in the properties of these blends can be attributed to the effective interaction of grafted maleic anhydride groups with the amino group in PA66. The results indicate that PBT‐g‐MA acts as an effective compatibilizer for the immiscible blends of PBT and PA66. © 2000 Society of Chemical Industry     

Dynamic mechanical properties and morphology of high‐density polyethylene/CaCO3 blends with and without an impact modifier

Dynamic mechanical analysis and differential scanning calorimetry were used to investigate the relaxations and crystallization of high‐density polyethylene (HDPE) reinforced with calcium carbonate (CaCO₃) particles and an elastomer. Five series of blends were designed and manufactured, including one series of binary blends composed of HDPE and amino acid treated CaCO₃ and four series of ternary blends composed of HDPE, treated or untreated CaCO₃, and a polyolefin elastomer [poly(ethylene‐co‐octene) (POE)] grafted with maleic anhydride. The analysis of the tan δ diagrams indicated that the ternary blends exhibited phase separation. The modulus increased significantly with the CaCO₃ content, and the glass‐transition temperature of POE was the leading parameter that controlled the mechanical properties of the ternary blends. The dynamic mechanical properties and crystallization of the blends were controlled by the synergistic effect of CaCO₃ and maleic anhydride grafted POE, which was favored by the core–shell structure of the inclusions. The treatment of the CaCO₃ filler had little influence on the mechanical properties and morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3907–3914, 2007     

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.