Properties of Paper Sludge Filled Polypropylene (PP)/Ethylene Propylene Diene Terpolymer (EPDM) Composites: The Effect of Silane-Based Coupling Agent

Paper sludge was used as a filler in PP/EPDM composites and 3-aminopropyl triethoxysilane (3-APE) was used in this study as a coupling agent. The effects of filler loading and 3-APE on the mechanical properties, water absorption, morphology, and thermal properties of the composites were investigated. It was found that incorporation of a silane coupling agent (3-APE) increased the stabilization (equilibrium) torque, tensile strength, and Young's modulus but decreased the elongation at break and water absorption. Scanning electron microscopy (SEM) study of the tensile fracture surface of the composites indicated that the presence of 3-APE increased the interfacial interaction between paper sludge and PP/EPDM matrix. The addition of a silane coupling agent also increased the crystallinity of PP and thermal stability of PP/EPDM/PS composites.     

Mixing efficiency in co‐rotating batch mixer for preparation of NR/EPDM blends

An in‐house developed co‐rotating batch mixer was used to prepare the blends of natural rubber (NR) and ethylene‐propylene‐diene terpolymer (EPDM) in the present work. Phase morphology and magnitude of dispersive mixing efficiency offered by the in‐house developed co‐rotating batch mixer and a conventional counter‐rotating batch mixer were compared. It has been found that the co‐rotating batch mixer equipped with the MX2 rotor configuration could improve the dispersive mixing efficiency of NR/EPDM blends considerably. A poor state‐of‐mix in blends, particularly at high fill factor, could be overcome by the utilization of MX2 rotor configuration where the extensional flow is probably facilitated in the converging zones. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Comparison of ethylene‐propylene diene terpolymer composites filled with natural and synthesized micas

In this paper, EPDM/mica composites were prepared by filling synthesized mica and natural mica separately into ethylene‐propylene diene terpolymer (EPDM) using melt blending technique. Microstructures, electrical properties, gas resistance, and mechanical properties of two EPDM/mica composites were investigated systematically. FTIR show that hydroxyl groups exist on the surface of the micas. These structural hydroxyls could be active sites conducive to the surface modification of mica. XRD analyses reveal that the natural mica is crystalline and the synthesized mica is amorphous. After being modified with silane coupling agent Si69, mica was only exfoliated into smaller micron agglomerates dispersing in EPDM, but the dispersion of amorphous synthesized mica was better. So the EPDM/synthesized mica composite possessed better mechanical property, electrical insulation property, and gas permeability resistance. It is expected that better improvement would be achieved, if mica is exfoliated further into nanosheets dispersing in the rubber matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Reactive Compatibilization of Polyamide 6 with Isocyanate Functionalized Ethylene‐Propylene Copolymer

Reactive compatibilization of ethylene‐propylene copolymer functionalized with allyl (3‐isocyanato‐4‐tolyl) carbamate (TAI) isocyanate (EPM‐g‐TAI) and polyamide 6 (PA6) was investigated in this paper. FTIR analysis revealed the evidence of a chemical reaction between the end groups of PA6 and EPM‐g‐TAI. Thermal, rheological, morphological, and mechanical properties of the resultant system were examined. DSC analysis indicated that the crystallization of PA6 in PA6/EPM‐g‐TAI blends was inhibited, due to the chemical reaction that occurs at the interface of PA6 and EPM‐g‐TAI. Rheological measurement showed that complex viscosity and storage modulus of PA6/EPM‐g‐TAI were both dramatically enhanced compared to those of PA6/EPM at the same blending composition. After examining the morphology of both blending systems, smaller particle size, more homogeneous distribution of domains and improved interfacial adhesion between matrix and domains were observed in the compatibilized system. Mechanical properties such as tensile strength, Young's modulus, flexural strength and modulus, as well as notched and un‐notched impact strength of PA6/EPM‐g‐TAI blends were also found to improve gradually with increasing the content of grafted TAI.

Tensile modulus of the blends versus rubber content.     

Evidences of solvent‐induced miscibility in polychloroprene‐co‐ethylene‐propene diene terpolymer blends

Solvent dependent changes in the compatibility behavior of Polychloroprene/Ethylene–propylene–diene terpolymer blends (CR/EPDM) have been investigated using dilute solution viscometry and solvent permeability analysis. To predict the compatibility of rubber blends of different compositions in solvents of different cohesive energy densities, Huggins interaction parameter (ΔB), hydrodynamic interaction (Δη) and Sun's parameter (α) were evaluated from the analysis of the specific and reduced viscosity data of two and three‐component polymer solutions. Miscibility criteria were not satisfied for CR/EPDM blends over the entire composition range in toluene, xylene, and carbon tetrachloride (CCl₄), however, a narrow miscibility domain was observed in chloroform (CHCl₃) for CR/EPDM/CHCl₃ system. These results were further corroborated with the analysis of heat of mixing (ΔH_m) and polymer–polymer interaction parameter (χ₁₂), for all rubber blend compositions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Waste and Virgin LDPE/PET Blends Compatibilized with an Ethylene‐Butyl Acrylate‐Glycidyl Methacrylate (EBAGMA) Terpolymer, 1

Summary: This work is aimed at studying the morphology and the mechanical properties of blends of low density polyethylene (LDPE) and poly(ethylene terephthalate) (PET) (10, 20, and 30 wt.‐% of PET), obtained as both virgin polymers and urban plastic waste, and the effect of a terpolymer of ethylene‐butyl acrylate‐glycidyl methacrylate (EBAGMA) as a compatibilizer. LDPE and PET are blended in a single screw extruder twice; the first extrusion to homogenize the two components, and the second to improve the compatibilization degree when the EBAGMA terpolymer is applied. Scanning electron microscopy (SEM) analysis shows that the fractured surface of both the virgin polymer and the waste binary blends is characterized by a gross phase segregation morphology that leads to the formation of large PET aggregates (10–50 µm). Furthermore, a sharp decrease in the elongation at break and impact strength is observed, which denotes the brittleness of the binary blends. The addition of the EBAGMA terpolymer to the binary LDPE/PET blends reduces the size of the PET inclusions to 1–5 µm with a finer dispersion, as a result of an improvement of the interfacial adhesion strength between LDPE and PET. Consequently, increases of the tensile properties and impact strength are observed.

SEM micrographs of the fracture surface of a waste 70/30 LDPE/PET blend (R30) and of its blend with 15 pph of EBAGMA (R30C). Magnification × 1 000.     

Determination methods of the grafting yield in glycidyl methacrylate‐grafted ethylene/propylene/diene rubber (EPDM‐g‐GMA): Correlation between FTIR and 1H‐NMR analysis

A normalized and universally applicable calibration function for the Fourier‐transformed infrared (FTIR) quantification of the glycidyl methacrylate (GMA) grafting yield in polymers of known compositions having ethylene block sequences was established. The ¹H nuclear magnetic resonance (¹H‐NMR) spectroscopy results achieved on different GMA‐grafted ethylene/propylene/diene rubber (EPDM‐g‐GMA) and ethylene/GMA copolymers were correlated to their FTIR data to calibrate the relative determination of the FTIR method. Both direct and indirect standardization approaches were followed and evaluated. The calibration deduced was used to investigate the free radical grafting reaction of GMA on EPDM rubber in the melt phase. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2616–2624, 1999     

Flow Behavior of Polypropylene/Ethylene-Propylene Diene Terpolymer/Natural Rubber (PP/EPDM/NR) Blends by Torque Rheometer: The Effect of N,N-m-Phenylene Bismaleimide (HVA-2) Addition

Blends of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) with different ratio were investigated using a Haake torque rheometer. The effect of N,N-m-phenylene bismaleimide (HVA-2) addition on the flow behavior of PP/EPDM/NR blends also was studied. The torque data was collected at different rotor speeds in the range of 30–60 rpm and different processing temperatures in the range of 170–190°C. The recorded data were interpreted in terms of apparent shear rate, apparent shear stress, and apparent viscosity. The shear stress–shear strain curve shows that all blends follow the power law where the pseudoplasticity behavior of melt viscosity increases with increasing NR content as well as addition of HVA-2. The apparent viscosity of the blends was found to increase with increasing NR content in the blend. The addition of HVA-2 increases the apparent viscosity due to the formation of cross-linking in rubber phase. However, blends with HVA-2 show lower flow activation energies than do similar blends without HVA-2. Scanning electron microscopy (SEM) shows good correlation with the flow properties of the blends.     

EPDM与马来酸酐的反应挤出接枝

用同向双螺杆挤出机,对三元乙丙共聚物（EPDM）进行熔融接枝马来酸酐（MAH）,考察了单体、引发剂（DCP）用量和加工条件对接枝率的影响。结果表明,在EPDM接枝MAH的反应中,随着DCP用量的增加,接枝率增大,随着MAH用量的增加,接枝率趋于一个平衡值,较佳的实验配方为EPDM：MAH：DCP=100：1：0.03。     

Compatibilization of nitrile‐butadiene rubber/ethylene‐propylene‐diene monomer blends by mercapto‐modified ethylene‐vinyl acetate copolymers

Mercapto‐modified ethylene‐vinyl acetate (EVASH) has been employed as a reactive compatibilizing agent for nitrile‐butadiene rubber (NBR)/ethylene‐propylene‐diene monomer (EPDM) blends vulcanized with a sulfur/2,2′‐dithiobisbenzothiazole (MBTS) single accelerator system and a (sulfur/MBTS/tetramethylthiuram disulfide (TMTD) binary accelerator system. The addition of 5.0 phr EVASH resulted in a significant improvement in the tensile properties of blends vulcanized with the sulfur/MBTS system. In addition to better mechanical performance, these functionalized copolymers gave rise to a more homogeneous morphology and, in some cases, better aging resistance. The compatibilization was not efficient in blends vulcanized with the S/MBTS/TMTD binary system, probably because of the faster vulcanization process occurring in this system. The good performance of these EVASH samples as compatibilizing agents for NBR/EPDM blends is attributed to the higher polarity of these components that is associated with their lower viscosity. Dynamic mechanical analysis also suggested a good interaction between the phases in the presence of EVASH. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1404–1412, 2004     

Miscibility of blends of ethylene‐propylene‐diene terpolymer and polypropylene

The miscibility of polymers is not only an important basis for selecting a proper blending method, but it is also one of the key factors in determining the morphology and properties of the blends. The miscibility between ethylene‐propylene‐diene terpolymer (EPDM) and polypropylene (PP) was explored by means of dynamic mechanical thermal analysis, transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The results showed that a decrease in the PP content and an increase of the crosslinking density of EPDM in the EPDM/PP blends caused the glass‐transition temperature peaks of EPDM to shift from a lower temperature to higher one, yet there was almost no variance in the glass‐transition temperature peaks of PP and the degree of crystallinity of PP decreased. It was observed that the blends prepared with different mixing equipment, such as a single‐screw extruder and an open mill, had different mechanical properties and blends prepared with the former had better mechanical properties than those prepared with the latter. The TEM micrographs revealed that the blends were composed of two phases: a bright, light PP phase and a dark EPDM phase. As the crosslinking degree of EPDM increased, the interface between the phases of EPDM and PP was less defined and the EPDM gradually dispersed in the PP phase became a continuous phase. The results indicated that EPDM and PP were both partially miscible. The mechanical properties of the blends had a lot to do with the blend morphology and the miscibility between the blend components. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 315–322, 2002     

Preparation and Characterization of Temperature‐Sensitive Poly(Styrene‐Butadiene‐Styrene)/Poly(N‐Isopropylacrylamide) Hydrogel Elastomer with Interpenetrating Polymeric Networks

A poly(styrene‐butadiene‐styrene)/poly(N‐isopropylacrylamide) (SBS/PNIPAM) hydrogel elastomer with interpenetrating polymeric network structure is prepared by using solution free radical polymerization in benzene/tetrahydrofuran solvent mixture. The characterizations of hydrogel elastomers are investigated by Fourier transform infrared spectroscopy, scanning electron microscope, rheology, equilibrium swelling studies, and oscillatory swelling study. Results show that these hydrogel elastomers exhibit a temperature‐sensitivity inherited from PNIPAM component at the temperature around 30 °C. Besides, change with tetrahydrofuran to different proportion in solvent mixtures, constituent, and properties as gel content, swelling capacity, mechanical strength and volume phase transition degree are affected deeply.     

The dynamic mechanical analysis,impact, and morphological studies of EPDM–PVC and MMA‐g‐EPDM–PVC blends

The dynamic mechanical studies, impact resistance, and scanning electron microscopic studies of ethylene propylene diene terpolymer–poly(vinyl chloride) (EPDM–PVC) and methyl methacrylate grafted EPDM rubber (MMA‐g‐EPDM)–PVC (graft contents of 4, 13, 21, and 32%) blends were undertaken. All the regions of viscoelasticity were present in the E′ curve, while the E″ curve showed two glass transition temperatures for EPDM–PVC and MMA‐g‐EPDM–PVC blends, and the T_g increased with increasing graft content, indicating the incompatibility of these blends. The tan δ curve showed three dispersion regions for all blends arising from the α, β, and Γ transitions of the molecules. The sharp α transition peak shifted to higher temperatures with increasing concentration of the graft copolymer in the blends. EPDM showed less improvement while a sixfold increase in impact strength was noticed with the grafted EPDM. The scanning electron microscopy micrographs of EPDM–PVC showed less interaction between the phases in comparison to MMA‐g‐EPDM–PVC blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1959–1968, 1999     

Toughening of poly(propylene carbonate) by hyperbranched poly(ester‐amide) via hydrogen bonding interaction

Poly(propylene carbonate) (PPC) is a biodegradable alternative copolymer of propylene oxide and carbon dioxide. As an amorphous polymer with lower glass transition temperature around 35 °C, PPC shows poor mechanical performance in that it becomes brittle below 20 °C and its dimensional stability deteriorates above 40 °C; thus toughening of PPC is urgently needed. Here we describe a biodegradable hyperbranched poly(ester‐amide) (HBP) that is suitable for this purpose. Compared with pure PPC, the PPC/HBP blend with 2.5 wt% HBP loading showed a 51 °C increase in thermal decomposition temperature and a 100% increase in elongation at break, whilst the corresponding tensile strength remained as high as 45 MPa and tensile modulus showed no obvious decrease. Crazing as well as cavitation was observed in the scanning electron microscopy images of the blends, which provided good evidence for the toughening mechanism of PPC. The intermolecular hydrogen bonding interaction confirmed by Fourier transform infrared spectral analysis proved to be the reason for the toughening phenomenon. Copyright © 2011 Society of Chemical Industry     

Toughening and compatibilization of polypropylene/polyamide‐6 blends with a maleated–grafted ethylene‐co‐vinyl acetate

In this article, maleated–grafted ethylene‐co‐vinyl acetate (EVA‐g‐MA) was used as the interfacial modifier for polypropylene/polyamide‐6 (PP/PA6) blends, and effects of its concentration on the mechanical properties and the morphology of blends were investigated. It was found that the addition of EVA‐g‐MA improved the compatibility between PP and PA6 and resulted in a finer dispersion of dispersed PA6 phase. In comparison with uncompatibilized PP/PA6 blend, a significant reduction in the size of dispersed PA6 domain was observed. Toluene‐etched micrographs confirmed the formation of interfacial copolymers. Mechanical measurement revealed that the addition of EVA‐g‐MA markedly improved the impact toughness of PP/PA6 blend. Fractograph micrographs revealed that matrix shear yielding began to occur when EVA‐g‐MA concentration was increased upto 18 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3300–3307, 2006     

Molecular and Morphological Characterization of Immiscible SAN/EPDM Blends Filled by Nano Filler

The compatibilizing effect of nano sized calcium carbonate filler on immiscible blends of styrene‐co‐acrylonitrile/ethylene propylene diene (SAN/EPDM) was examined. The surface energy of the calcium carbonate was modified by stearic acid. The compatibility of SAN/EPDM blends was studied by following the glass transition temperature T_g by DSC. SEM was used to observe the blend morphology and the X‐ray analyzer was used to detect the calcium from filler in samples. Mechanical properties of the blends were determined, and related to changes of polymer‐filler interactions and morphology. The results suggest that the morphology of the SAN/EPDM blends studied was affected by the reduction of surface energy of the filler.

SEM micrograph of an SAN/EPDM blend with 5% of maximally treated filler.     

Development of halogen‐free flame‐retardant thermoplastic elastomer polymer blend

Ethylene‐propylene diene rubber (EPDM) and isotactic polypropylene (iPP) blends have widest industrial applications that require a degree of flame retardancy. Halogen‐free intumescent technology based on phosphorous salt is a significantly advanced approach to make the polymer flame‐retardant. Both ammonium polyphosphate and ethylenediamine phosphate are important intumescent compounds. Their combination with carbonific and spumific agents were studied in binary blends of EPDM/PP. The polymer system was vulcanized online during melt mixing. Intumescent flame‐retardant polymer systems exhibit good flame‐retardancy with optimum comparable physiomechanical, electrical, and fluid resistance properties, including lower smoke emission, which is essential to protect people because the visibility remains unaffected in the event of fire. Pronounced charring and intumescent effect appear to enhance the flame‐retardancy of the polymers. Possible expected intumescent mechanism is proposed based on the nonpyrolysis mechanism for the flame‐retarded polymer and the intumescent components. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 407–415, 2004     

Using fish scales (Sardina pilchardus) within ethylene‐propylene‐diene ter monomer rubber as bio‐based filler

Proper management of waste bio‐based materials is an important subject to protect the environment in a sustainable manner. In this study, ethylene‐propylene‐diene monomer (EPDM) composites with different fish scale content were prepared and properties of these composites were investigated. Mechanical tests, gel content, curing, and thermal properties were analyzed. In addition, rheological and morphological analyses were also carried out. It was seen that EPDM rubber and fish scale composite have a good compatibility. The addition of fish scale improved the mechanical properties of the final material. Moreover, an increase in gel content and in swelling ratio was obtained for the composite samples containing fish scale. Moving die rheometer tests are concluded that fish scale has acted like an agent that improves the vulcanization process. Thermal gravimetric analysis result pointed out that the thermal stability of the composite developed is higher than neat EPDM. It was concluded that 40 phr fish scale content gives best results. The kinetic study demonstrated that fish scale is compatible with the matrix and improves the vulcanization process. The results have shown that using the fish scale as a bio‐based filler is a facile and green way to accommodate the bio‐based wastes. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46698.     

Toughening of an epoxy resin with hydroxy‐terminated poly(arylene ether nitrile) with pendent tertiary butyl groups

Hydroxy‐terminated poly(arylene ether nitrile) oligomers with pendent tert‐butyl groups (PENTOH) were synthesized by the nucleophilic aromatic substitution reaction of 2,6‐dichlorobenzonitrile with tert‐butyl hydroquinone in N‐methyl‐2‐pyrrolidone medium with anhydrous potassium carbonate as a catalyst at 200°C in a nitrogen atmosphere. The PENTOH oligomers were blended with diglycidyl ether of bisphenol A epoxy resin and cured with 4,4′‐diaminodiphenyl sulfone. The curing reaction was monitored with infrared spectroscopy and differential scanning calorimetry. The morphology, fracture toughness, and thermomechanical properties of the blends were investigated. The scanning electron micrographs revealed a two‐phase morphology with a particulate structure of the PENTOH phase dispersed in the epoxy matrix, except for the epoxy resin modified with PENTOH with a number‐average molecular weight of approximately 4000. The storage modulus of the blends was higher than that of the neat epoxy resin. The crosslink density calculated from the storage modulus in the rubbery plateau region decreased with an increase in PENTOH in the blends. The fracture toughness increased more than twofold with the addition of PENTOH oligomers. The tensile strength of the blends increased marginally, whereas the flexural strength decreased marginally. The dispersed PENTOH initiated several toughening mechanisms, which improved the fracture toughness of the blends. The thermal stability of the epoxy resin was not affected by the addition of PENTOH to the epoxy resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Mechanical and morphological properties of white rice husk ash filled polypropylene/ethylene‐propylene‐diene terpolymer thermoplastic elastomer composites

The performance of white rice husk ash (WRHA) as filler for polypropylene (PP)/ethylene‐propylene‐diene terpolymer (EPDM) thermoplastic elastomer (TPE) composites was investigated. The composites with different filler loadings were prepared in a Brabender plasticorder internal mixer. Both unvulcanized and dynamically vulcanized composites were prepared. Mixing and vulcanization processes of the composites were monitored through the typical Brabender torque‐time curves. The mechanical properties and morphology of the composites were also studied. The Brabender torque curves revealed that the dynamic vulcanization process employed was successful and incorporation of filler has no adverse effect on the processibility of the composites. Incorporation of WRHA improves the tensile modulus and flexural modulus and lowers tensile strength, elongation at break, tear strength, and toughness of both types of composites. Dynamic vulcanization significantly enhances the mechanical and TPE properties of the composites. Dynamic mechanical analysis (DMA) study revealed the existence of two phases in both types of composites. It further shows that neither dynamic vulcanization nor filler agglomeration has played a prominent role in the compatibility of the composites. Thermogravimetric investigation shows that dynamic vulcanization or WRHA loading has not adversely affected the thermal stability of the composites. The scanning electron micrographs provide evidence for the tendency to form filler agglomerates with increasing filler loading, better filler dispersion of dynamically vulcanized composites over unvulcanized composites, and effective vulcanization of elastomer phase of the composites in the presence of filler. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 438–453, 2002