Increasing Compatibilizer Content Research Articles

Poly(butylene terephthalate)/poly(ethylene glycol) blends with compatibilizers

AbstractPolymer blend systems offer a versatile approach for tailoring the properties of polymer materials for specific applications. In this study, we investigated the compatibility of polybutylene terephthalate (PBT) and poly(ethylene glycol) (PEG) blends processed using a twin‐screw extruder, with the aim of enhancing their compatibility. Phthalic anhydride (PAn) and phthalic acid (PAc) were used as potential compatibilizers at different concentrations to improve interfacial interactions between PBT and PEG. Blend morphologies were characterized using scanning electron microscopy, which revealed improved interfacial compatibility and reduced phase separation with the incorporation of small amounts of PAn and PAc. Differential scanning calorimetry analysis indicated changes in the melting temperature (Tm) and glass transition temperature (Tg) of the blends owing to the compatibilizing effects of PAn and PAc. Dynamic mechanical analysis further corroborated the influence of the compatibilizers on the Tg and viscoelastic behavior. Thermogravimetric analysis demonstrated enhanced thermal stability with the addition of either PAn or PAc. Rheological measurements indicated an increase in complex viscosity with increasing compatibilizer content, indicating improved compatibility. The degradation point (Td) of PBT/PEG blend increased from 158 to 200 and 319°C with the incorporation of 5 phr PAn and 2 phr PAc, respectively. Mechanical properties, including tensile strength, Young's modulus, and Izod impact strength, were evaluated. For instance, the tensile strength of PBT/PEG blend was enhanced from 43.5 to 48.7 and 49.7 MPa by incorporating 5 phr PAn and 2 phr PAc, respectively. However, the impact strength of PBT/PEG blend increased from 3.0 to 4.3 and 4.2 kJ/m2 with the addition of 1 phr PAn and 1 phr PAc, respectively. The findings demonstrated that adding 5 phr PAn or 2 phr PAc to the PBT/PEG blends was advantageous, achieving a harmony of performance benefits and compromises. Rheological observations contributed significantly to the mechanical and thermal properties. Overall, the study highlights the significance of utilizing PAn and PAc as effective compatibilizers for enhancing the properties of PBT/PEG blends, making them potential candidates for various applications.

Compatibilization of PA6/ABS blend by SEBS-g-MA: morphological, mechanical, thermal, and rheological properties

Blends polyamide 6 (PA6) and acrylonitrile-butadiene-styrene (ABS) were compatibilized with a styrene–(ethylene–butene)–styrene triblock copolymer grafted with maleic anhydride (SEBS-g-MA). In particular, the effects of ABS (0–100 wt%) and compatibilizer (0, 8, and 16 wt%) content were studied. The blends were first prepared by twin-screw extrusion, and different specimens were prepared by injection molding. From the samples produced, the effects of blend composition on morphological, mechanical, rheological, and thermal properties are reported. The structural analysis confirmed that the original blend is immiscible but showed some compatibilization when in the presence of SEBS-g-MA. Incorporation of the compatibilizer and ABS showed negligible effect on the melting behavior of PA6. The compatibilized blends showed higher tensile strength compared with uncompatibilized ones. However, Young’s modulus decreased with increasing compatibilizer content. The mechanical results were confirmed by rheological measurements in terms of interaction between each components in the blend.

Physico-thermal properties of kenaf fiber/high-density polyethylene/maleic anhydride compatibilized composites

Kenaf fiber/high-density polyethylene/maleic anhydride (MA)-compatibilized composites were melt mixed in a twin-screw extruder and molded using injection molding machine. Physicothermal properties of the composites were studied at different percentages of compatibilizer contents using various techniques. The addition of 8% compatibilizer into 8.5 and 17.5 wt% fiber content improved the adhesion and tensile strength by 14.5% and 13.6%, respectively. Compatibilized samples exhibited higher peak load and fracture energy on impact testing compared to the samples without maleic anhydride compatibilizer. The effect of the addition of maleic anhydride compatibilizer on peak load and fracture energy was observed to be at its highest at 8%. Differential scanning calorimetric measurements revealed that the melting enthalpy and degree of crystallinity of composites increased with increasing compatibilizer content up to 8% and then decreased at 12% compatibilizer content. Dynamic mechanical analysis showed that the storage modulus of composites was increased, but the loss modulus and tangent delta were decreased after the addition of compatibilizer. This indicates that compatibilized composites produced have improved toughness and reduced stiffness.

Influence of PP-g-MA Compatibilization on the Mechanical and Wear Properties of Polypropylene/Thermoplastic Polyurethane Blends

ABSTRACT Polypropylene/thermoplastic polyurethane (PP/TPU) blends of different weight ratios (75/25 and 25/75) were processed by melt blending using a maleic anhydride–grafted polypropylene (PP-g-MA) copolymer as coupling agent. The influence of the amount of the coupling agent (0, 3, 5, 7, 9, 11 phr) on the mechanical, frictional, and wear properties of the blends were characterized through tensile test, three-point bending, dynamic mechanical analysis (DMA), and ball-on-disc wear tests. PP-g-MA was found to be an effective compatibilizer for PP/TPU blends, and mechanical and wear properties of the blends were proved to be strongly impacted by the amount of coupling agent. Tensile strength of the blends tends to increase with increasing the PP-g-MA content and 9 phr is found to be optimal for both concentrations of the blends. Good miscibility of the blends with increasing compatibilizer content was also verified by DMA. From the wear test results, the compatibilizer was found to be more effective in PP75/TPU25 blends, in parallel with the results of the mechanical tests. The PP75/TPU25 blend with 11 phr PP-g-MA content was superior to the other blends. In addition, in this work, a new model based on image processing is proposed that provides accurate and fast wear rate measurement and detailed information of the wear track, especially in heterogeneous materials. Using the model, the homogeneity of the wear track widths was proved to be strongly impacted and improved by the use of a coupling agent.

Effects of poly(styrene-co-maleic anhydride) on the performance of LGF/TPU/ABS composites

Abstract A series of long glass fiber-reinforced thermoplastic polyurethane (TPU) elastomers and acrylonitrile-butadiene-styrene (ABS) copolymer (LGF/TPU/ABS) composites were prepared using self-designed impregnation device. Poly(styrene-co-maleic anhydride) was employed to increase the compatibility between glass fiber and matrix resin and thus obtain the excellent properties of composites. The dynamic mechanical properties of the composites have been investigated using dynamic mechanical thermal analysis. The results indicated that the storage modulus of the composites gradually increases and then decreases with increasing compatibilizer content. In addition, the low temperature peak of the composites shifts to higher temperature with increasing compatibilizer content. The thermal properties of the composites were studied by thermogravimetric analyzer. In addition, the morphology and mechanical properties of the composites are investigated by scanning electron microscopy, a universal testing machine, and a ZBC-4 Impact Pendulum.

An investigation on recycled PET/PP and recycled PET/PP‐EP compatibilized blends: Rheological, morphological, and mechanical properties

ABSTRACTThe effectiveness of P(E‐co‐MA‐co‐GMA) as a compatibilizer for recycled PET/PP and recycled PET/PP‐EP (polypropylene (ethylene‐propylene) heterophase copolymer) blends was investigated by means of morphological (scanning electron microscopy), rheological (small amplitude oscillatory shear), mechanical (tensile, flexural and impact tests), and thermal (differential scanning calorimetry) properties. Compatibilizer concentration ranged from 1 to 5 wt % with respect to the whole blend. All blends were obtained in a 90/10 composition using a twin screw extruder. Compatibilization effects for PETr/PP‐EP were more pronounced due to ethylene segments present in both PP‐EP and P(E‐co‐EA‐co‐GMA). PETr/PP‐EP has shown greater dispersed phase size reduction, a more solid‐like complex viscosity behavior and larger storage modulus at low frequencies in relation to PETr/PP blend. For both investigated blends, mechanical properties indicated an improvement in both elongation at break and impact strength with increasing compatibilizer content. PETr/PP‐EP blends showed improved performance for the same level of compatibilizer content. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41892.

Study on the effect of dispersion phase morphology on porous structure of poly (lactic acid)/poly (ethylene terephthalate glycol-modified) blending foams

A methodology for blending foam of poly (lactic acid) (PLA)/poly (ethylene terephthalate glycol-modified) (PETG) was proposed. PLA/PETG blends were prepared through a melt blending method, using multiple functionality epoxide as reactive compatibilizer. The effects of blending ratio and compatibilizer content on the dispersion morphology, molecular structure, mechanical properties, and rheological behavior of PLA/PETG blends were studied. Then PLA/PETG blends were foamed using supercritical CO2 as physical blowing agent, and their porous structure, pore size, as well as pore density were investigated. The results showed that the mechanical properties and rheological parameters such as melt strength and melt elasticity, as well as the porous structure of the foams dispersion morphology of PLA/PETG blends were affected strongly. The melt elasticity of PLA/PETG blends increased with increasing compatibilizer content. Dispersion phase morphology of PLA/PETG blends also had a significant effect on the pore density of all the samples. The results indicated that homogeneous and finer porous morphology of PLA/PETG foams with high expansion ratio could be achieved with a proper content of compatibilizer in the blends.

Effect of Compatibilizer Content on the Shear and Extensional Rheology of Polypropylene/Clay Nanocomposites

The shear and extensional rheology of polypropylene (PP)/organoclay nanocomposites in the presence of various maleic anhydride grafted polypropylene (PP-g-MA) compatibilizer concentrations were investigated. The PP nanocomposites were prepared via direct melt intercalation in an internal mixer. The structures of the nanocomposites were characterized by X-ray diffraction (XRD) and scanning electron microscopy. It was found that both the compatibilized and uncompatibilized nanocomposites could form an intercalated structure. However, the organoclay particles can disperse well only in the compatibilized systems. The linear viscoelastic properties, including the storage modulus G′ and complex viscosity η* were very sensitive to the microstructure of the nanocomposites. The extensional viscosities of PP nanocomposites were enhanced under a low deformation rate with increasing compatibilizer content and displayed a lack of superposition for different strain rates. It was proposed that the lack of superposition might originate from the formation of a three-dimensional organoclay network, which decreased in its complexity and strength as the deformation rate increased.

Investigation on the correlation between rheology and morphology of PA6/ABS blends using ethylene acrylate terpolymer as compatibilizer

AbstractPhase morphology and rheological behavior of polyamide 6 (PA6)/acrylonitrile butadiene styrene (ABS) polymers blends was studied using scanning electron microscopy and rheometry. The results showed that the phase morphology and rheological properties depends on blend composition. We evaluated the effect of addition of ABS as dispersed phase and EnBACO‐MAH (ethylene n‐butyl acrylate carbon monoxide maleic anhydride) as a compatibilizer on the morphological and rheological behaviors of PA6/ABS blends. It was concluded that there is a good agreement between the results obtained from rheological and morphological studies. As a consequence, addition of the ABS and compatibilizer weight percent led to a significant change in morphological structure and a great mounting in the viscosity as well as the elasticity. The rheological properties results demonstrate that adding compatibilizer to polymer blends led to increasing the crossover point, which shows a transition from a high viscous to a considerably more elastic behavior. Also, the slow transition of relaxation time peak from the peak of the PA6 to the peak of the ABS implies increasing the miscibility of the PA6/ABS blend components by increasing compatibilizer content. In addition, the Carreau–Yasuda model was used to extract information on rheological properties (zero shear viscosity and relaxation time) for PA6/ABS/EnBACO‐MAH blends by fitting the experimental data with this model. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Effect of Compatibilizer on Mechanical, Morphological, and Thermal Properties of Chemimechanical Pulp-reinforced PP Composites

Mechanical, morphological, and thermal properties of injection molded, chemimechanical pulp (CMP)-reinforced polypropylene (PP) composites were investigated as a function of different concentrations of maleic anhydride-grafted PP. It was found that tensile strength and failure strain and the notched impact strength increased progressively with increasing compatibilizer content, whereas the addition of any concentration of compatibilizer did not alter the tensile modulus. Scanning electron microscopy — micrographs of tensile fracture surfaces of composites with 2% compatibilizer indicated very little fiber pullout and many fractured fibers. The thermal stability of pure PP was found to be higher than that of CMP-reinforced PP composites. With addition of compatibilizer, the thermal stability of the composites was slightly increased. The activation energy was determined to describe the energy consumption of the initiation of the thermal degradation process. The activation energy of the composites was found to depend on the dispersion and interfacial adhesion of CMP and PP matrix.

Investigation on the use of coir fiber as alternative reinforcement in polypropylene

AbstractPolypropylene/coir fiber composites were prepared according to an experimental statistical design, in which the independent variables, coir fiber, and compatibilizer content, were varied. The compatibilizer used was maleic anhydride grafted polypropylene (PP‐g‐MA). Compatibilizer free composites were also prepared. Composites were processed in a corotating twin‐screw extruder and submitted to mechanical and morphological analyses. The effects of the independent variables on the mechanical properties were assessed through tensile strength, elongation at break, flexural modulus, and impact strength. The morphological properties were assessed by scanning electron microscopy (SEM). The results indicated the need for using compatibilizers in the composites due to the incompatibility of PP and coir fiber. The variable with the strongest effect on the properties was coir content, whose increase caused increase in tensile strength, impact strength and elastic modulus, and decrease in elongation at break. The presence of PP‐g‐MA was fundamental to achieving the aforementioned results. The effect of increasing compatibilizer content was only observed for the elastic modulus. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Characterization of nylon 6/ABS blends with and without a maleated polybutadiene as compatibilizer

The physical properties of nylon 6/poly(acrylonitrile-butadiene-styrene) terpolymer (ABS) blends using a maleated polybutadiene (denoted PB-g-MA) as compatibilizer were investigated. The morphology results reveal that ABS domain sizes decrease with an increasing compatibilizer content, suggesting the good interaction between the nylon 6 matrix and the ABS dispersed phase. Cooling conditions and compatibilizer contents strongly affect the crystalline structure of nylon 6, as determined from X-ray diffraction and non-isothermal crystallization thermal analyses. The coexistence of α- and predominantly γ-form crystals for the 10 phr compatibilized blends was observed. Isothermal crystallization kinetics suggests that the introduced compatibilizer impeded the growth rate of the crystals, especially for the higher compatibilizer content. The compatibilizer was beneficial in enhancing the thermal stability of the blends.

Reactive Compatibilization of PA6/LDPE Blends with Glycidyl Methacrylate Functionalized Polyolefins

AbstractSummary: Blends of polyamide‐6 (PA6) and low density polyethylene (LDPE) were compatibilized by melt mixing with various polyolefins functionalized with glycidyl methacrylate (GMA), i.e., GMA grafted LDPE (LDPE‐g‐GMA), GMA grafted styrene‐ethylene/butylene‐styrene block copolymer (SEBS‐g‐GMA) and ethylene‐co‐glycidyl methacrylate copolymer (E‐GMA). Blends with PA6/LDPE composition ratios of 25/75 and 75/25 wt.‐%/wt.‐% were prepared in a Brabender internal mixer and their properties were evaluated by SEM, rheological measurements and DSC. Morphological investigation by SEM showed a neat improvement of phase dispersion and interfacial adhesion in all compatibilized blends when compared to PA6/LDPE binary blends. The variation of the dispersed phase size was analyzed as a function of blend composition, compatibilizer concentration and GMA content. The emulsification curves of compatibilized blends showed that the equilibrium size of dispersed particles at the saturation concentration of copolymer was lower when PA6 was the major component. The finest dispersion of the LDPE phase (<0.25 μm) was observed in the presence of SEBS‐g‐GMA copolymer. LDPE‐g‐GMA and E‐GMA displayed a similar compatibilizing efficiency. In all cases, the blends with a polyamide matrix presented a marked rise in torque and melt viscosity with increasing compatibilizer content. These effects were accounted for by a reaction between the epoxide groups of LDPE‐g‐GMA and the carboxyl/amine end‐groups of PA6, leading to the formation of an interchain graft copolymer. The phase transition processes of PA6 in the blends were influenced by the compatibilizer content and the interfacial interactions between the polymer components, suggesting a different role for the compatibilizer at the PA6/LDPE interface.SEM micrograph of PA6/LDPE 25/75 blend compatibilized with 2.5 phr SEBS‐g‐GMA.magnified imageSEM micrograph of PA6/LDPE 25/75 blend compatibilized with 2.5 phr SEBS‐g‐GMA.

Review of melt-processed nanocomposites based on EVOH/organoclay

EVOH nanocomposites containing organically treated clays are unique systems in which the clay is strongly attracted to EVOH, thus affecting the morphology and the resultant thermal and mechanical properties. A strong effect of the processing conditions on morphology, thermal, and mechanical properties was observed. In highly interacting systems, under dynamic mixing conditions, in addition to a fracturing process of the clay particles, an onion-like delamination process is suggested. EVA-g-MA and LLDPE-g-MA, having polar groups, were studied as compatibilizers to further induce clay intercalation and exfoliation. The compatibilizers affected both the thermal and mechanical properties of the composites at different levels. Thermal analysis showed that with increasing compatibilizer content lower crystallinity levels result, until at a certain content no crystallization has taken place. A Ny-6 (nylon-6)/EVOH blend is an interesting host matrix for incorporation of low organoclay contents. The Ny-6/EVOH blend is a unique system that tends to hydrogen bond and also to in situ chemically react during melt mixing. The addition of clay seems to interrupt the chemical reaction between the two host polymers at certain compositions, leading to lower melt blending torque levels when clay is present. A competition between Ny-6 and EVOH regarding the intercalation process takes place. However, Ny-6 seems to lead to exfoliated structures, whereas EVOH forms intercalated structures, as revealed from combined XRD and TEM experiments, owing to thermodynamic considerations and preferential localization of the clay in Ny-6. Of special interest is the increased storage modulus seen by the presence of only 1 wt % clay, which was achieved by extrusion under high shear forces, leading to a completely exfoliated structure. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1931–1943, 2005

EVOH/clay nanocomposites produced by dynamic melt mixing

AbstractEthylene‐vinyl alcohol copolymer (EVOH)/clay nanocomposites were prepared via a dynamic melt‐intercalation process using a Brabender Plastograph or extruder. The phase morphology and the crystallization behavior of the nanocomposites were investigated, using differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). Mechanical properties were determined using an Instron machine. It was found that the viscosity of EVOH/clay mixtures increases with processing time. Thermal analysis of the EVOH/clay nanocomposites showed that the melting temperature, crystallization temperature, and heat of fusion of the EVOH matrix sharply decrease when clay is added. XRD verified an increased gallery height for the clay in the composites. Maleic anhydride–grafted ethylene vinyl acetate (EVA‐g‐MA) or maleic anhydride–grafted linear low‐density polyethylene (LLDPE‐g‐MA) were added as compatibilizers of EVOH with clay, in various concentrations (1, 5 and 10 wt%). Significantly higher viscosity levels were obtained for the compatibilized systems as the torque dramatically increased when processed in the Brabender machine. Enhanced intercalation within the galleries was obtained. EVOH crystallinity decreased with increasing compatibilizer content, until at a certain content no crystallization took place. EVOH/clay composites were also processed in an extruder, showing improved mechanical properties for as low as 1 wt% clay. The strong EVOH/clay interactions are responsible for the unique behavior of their nanocomposites. Polym. Eng. Sci. 44:1019–1026, 2004. © 2004 Society of Plastics Engineers.

The effect of maleated compatibilizers on the structure and properties of EVOH/clay nanocomposites

AbstractThe effect of compatibilizers on the blending torque, crystallization behavior, intercalation level, thermal stability and morphology of EVOH/treated clay systems was investigated. Maleic anhydride‐grafted ethylene vinyl acetate (EVA‐g‐MA) or maleic anhydride‐grafted linear low density polyethylene (LLDPE‐g‐MA) were used as compatibilizers of EVOH with clay, in various concentrations (1, 5 and 10 wt%). The blends were processed using Brabender Plastograph and characterized by XRD, SEM, DSC, DMTA and TGA. X‐ray diffraction shows advanced intercalation within the galleries when the compatibilizers were added. Unique results were obtained for the EVOH/clay/compatibilizer systems, owing to a high level of interaction developed in these systems, which plays a major role. Thermal analysis showed that with increasing compatibilizer content, lower crystallinity levels result, until at a certain content no crystallization has taken place. Significantly higher viscosity levels were obtained for the EVOH/clay blends compared to the neat polymer, as seen by a dramatic torque increase when processed in the Brabender machine. The DMTA spectra showed lower Tg values for the compatibilized nanocomposites compared to the neat EVOH and the uncompatibilized composites. Storage modulus was higher compared to the uncompatibilized EVOH/clay blend when EVA‐g‐MA compatibilizer was added (at all concentrations), and only at low contents of LLDPE‐g‐MA. TGA results show significant improvement of the blends thermal stability compared to the neat EVOH, and to the uncompatibilized blend, indicating an advanced intercalation.

Observation of morphology in EPDM/nylon copolymer thermoplastic vulcanizates by atomic force microscopy

AbstractA thermoplastic vulcanizate (TPV) of an ethylene propylene diene terpolymer (EPDM) and nylon copolymer (PA) was prepared. Maleic anhydride‐grafted EPDM (EPDM‐g‐MAH) and MAH‐grafted EPR (EPR‐g‐MAH) were used as compatibilizers and sulfur was used as a curative. The phase morphology of EPDM/PA TPVs was investigated by atomic force microscopy (AFM). AFM images showed that, although there was a compatibilization reaction between EPDM‐g‐MAH and PA, phase inversion always existed for EPDM/EPDM‐g‐MAH/PA TPVs and the rubber phase could be finely dispersed in the PA matrix with an increasing compatibilizer content. For TPVs using EPR‐g‐MAH as a compatibilizer, three phases existed because of noncrosslinkability of EPR by sulfur. Crosslinked EPDM particles dispersed in a comatrix of PA and EPR‐g‐MAH could be observed by increasing the content of EPR‐g‐MAH to 26 wt %. For an EPR‐g‐MAH content of 26 wt %, the uncrosslinked EPR‐g‐MAH existing in the interface between crosslinked EPDM and PA tended to coalesce and thus resulted in a morphology of large rubber regions composed of small crosslinked particles. When the dosage of EPR‐g‐MAH was 52 wt %, the phase morphology of the blends changed to being one of PA and crosslinked EPDM particles dispersed in the MAH‐g‐EPR matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1242–1248, 2003

Phase structure and viscoelastic properties of compatibilized blends of PET and HDPE recyclates

AbstractImmiscible blends of recycled poly(ethylene terephthalate) (R‐PET), containing some amount of polymeric impurities, and high‐density polyethylene (R‐PE), containing admixture of other polyolefins, in weight compositions of 75 : 25 and 25 : 75 were compatibilized with selected compatibilizers: maleated styrene–ethylene/butylene–styrene block copolymer (SEBS‐g‐MA) and ethylene–glycidyl methacrylate copolymer (EGMA). The efficiency of compatibilization was investigated as a function of the compatibilizer content. The rheological properties, phase structure, thermal, and viscoelastic behavior for compatibilized and binary blends were studied. The results are discussed in terms of phase morphology and interfacial adhesion among components. It was shown that the addition of the compatibilizer to R‐PET‐rich blends and R‐PE‐rich blends increases the melt viscosity of these systems above the level characteristic for the respective binary blends. The dispersion of the minor phase improved with increasing compatibilizer content, and the largest effects were observed for blends compatibilized with EGMA. Calorimetric studies indicated that the presence of a compatibilizer had a slight affect on the crystallization behavior of the blends. The dynamic mechanical analysis provided evidence that the occurrence of interactions of the compatibilizer with blend components occurs through temperature shift and intensity change of a β‐relaxation process of the PET component. An analysis of the loss spectra behavior suggests that the optimal concentration of the compatibilizers in the considered blends is close to 5 wt %. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1423–1436, 2001