Synthesis and properties of methacrylonitrile–EPDM–2–vinylnaphthalene graft terpolymer

The graft terpolymer of methacrylonitrile (MAN) and 2-vinylnaphthalene (2-VN) onto ethylene-propylene-diene terpolymer (EPDM) was synthesized in toluene using benzoyl peroxide (BPO) as an initiator. The effects of EPDM content, mole ratio of 2-VN to MAN, reaction time, reaction temperature, and initiator concentration on the graft copolymerization were examined. The synthesized graft terpolymer was identified by IR and ¹H-NMR spectroscopies. The light resistance, thermal stability, molecular weight, and tensile properties of the graft terpolymer were investigated by Fade-o-meter, thermogravimetric analysis, gel permeation chromatography (GPC), and a universal tensile machine (UTM). It was found that the light resistance and heat resistance as well as the tensile strength of the graft terpolymer are considerably better than those of the acrylonitrile-butadiene-styrene (ABS) terpolymer. © 1995 John Wiley & Sons, Inc.     

Synthesis and properties of acrylonitrile–EPDM–N-vinylcarbazole graft terpolymer

A graft terpolymer of acrylonitrile (AN) and N-vinylcarbazole (NVC) onto ethylene–propylene–diene terpolymer (EPDM) was synthesized in toluene using benzoyl peroxide. The effects of EPDM content, mole ratio of NVC to AN, reaction time, reaction temperature, and initiator concentration in the graft copolymerization were examined. The synthesized AN–EPDM–NVC graft terpolymers (AEVC) were identified by infrared (IR) and ¹H-NMR (nuclear magnetic resonance) spectra. The thermal stability, tensile strength, and light resistance of AEVC were investigated by using a Fade-o-Meter, thermogravimetric analyzer, and tensile tester. It was found that the heat resistance of AEVC is considerably better than that of acrylonitrile–butadiene–styrene (ABS) copolymer. © 1995 John Wiley & Sons, Inc.     

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     

Synthesis and properties of vinyltrimethoxysilane–EPDM–styrene graft terpolymer

The graft copolymerizations of vinyltrimethoxysilane (VTMO) and styrene (St) onto ethylene–propylene–diene terpolymer (EPDM) were carried out with benzoyl peroxide (BPO) as an initiator in toluene. The effects of EPDM concentration, mole ratio of VTMO to St, reaction time, reaction temperature, and initiator concentration on the graft copolymerizations were examined. The synthesized VTMO–EPDM–St graft terpolymers (VES) were confirmed by infrared and ¹H-NMR spectroscopies. The molecular weight, thermal stability, light resistance, and weatherability of the graft terpolymer were investigated by gel permeation chromatography, thermogravimetric analysis, and Fade-o-Meter. The number-average molecular weight was 109,000. It was found that the heat resistance and light resistance as well as weatherability of VES are considerably better than those of acrylonitrile–butadiene–styrene terpolymer. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1345–1352, 1998     

Synthesis and properties of acrylonitrile-EPDM-4-chlorostyrene graft copolymer

Graft copolymerization of acrylonitrile (AN) and 4-chlorostyrene (4-Clst) onto ethylene–propylene–diene terpolymer (EPDM) was carried out using benzoyl peroxide as initiator. The effects of EPDM content, initiator concentration, solvent, mole ratio of 4-Clst to AN, reaction time, and reaction temperature on the graft copolymerization were examined. It was found that the light resistance, weatherability, and thermal stability of the acrylonitrile–EPDM–4-chlorostyrene graft copolymer were considerably better than those of acrylonitrile–butadiene–styrene copolymer.     

Synthesis and properties of styrene–EPDM–vinyl acetate graft polymer

The styrene–EPDM–vinylacetate (SEV) graft polymer, which linked respectively the styrene (St) unit and vinylacetate the (VAc) unit to the ethylene–propylene–diene terpolymer (EPDM) backbone was synthesized by two‐step graft polymerizations: First the graft polymerization of VAc onto EPDM was carried out, and then St was added successively in the prepolymerized solution and further polymerized for a given period to obtain SEV. The effects of concentration of EPDM and an initiator, mole ratio of VAc to St, polymerization time, temperature, and solvent were examined on the graft polymerizations. The synthesized graft polymers (SEVs) that have different contents of St or VAc were identified by Fourier transform IR spectrum. The highest graft ratio has been obtained by 10 wt % of EPDM, 1.0 mole ratio of VAc to St, and 1.0 wt % of BPO in toluene for 48 h at 70°C. The glass transition temperature of SEV is lower than that of poly(vinyl acetate) (PVAc) and polystyrene (PS). The thermal stability of SEV is higher than that of PVAc, PS, and the acrylonitrile–butadiene–styrene (ABS) resin. The tensile strength of SEV was improved as compared with that of EPDM. The light resistance and weatherability of SEV were better than those of ABS. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2296–2304, 2000     

Syntheses and properties of N‐vinylpyrrolidione‐g‐EPDM and its modified polymer

The graft copolymerizations of N‐vinylpyrrolidione(NVP) onto ethylene–propylene–diene terpolymer (EPDM) were carried out with benzoyl peroxide (BPO) as an initiator in toluene. The synthesized EPDM‐g‐NVP (ENVP) was characterized by infrared (IR) spectroscopy and gel permeation chromatography (GPC). The effects of initiator and monomer concentrations, reaction time, and temperature were investigated in the graft copolymerization. The highest graft efficiency was obtained at 0.04 mol of NVP, 2 g of EPDM, 2 wt % of BPO and 80°C for 72 h. Modified ENVP (MENVP) was obtained by the reaction of ENVP and KOH in MeOH. Properties of EPDM, ENVP, and MENVP were investigated by a thermogravimetric analyzer (TGA), an instron tensile tester, a Fade‐O‐Meter, and a UV spectrophotometer. Tensile strength and light resistance of ENVP were better than those of MENVP. The dyeability of polymers was increased in following order: MENVP > ENVP > EPDM. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1177–1184, 1999     

Synthesis and photodegradable properties of methyl vinyl ketone–EPDM–styrene graft terpolymer

The graft terpolymerization of methyl vinyl ketone (MVK) and styrene (St) onto ethylene–propylene–diene terpolymer (EPDM) was carried out under various polymerization conditions. The synthesized graft terpolymer, MVK–EPDM–St (MVES), was identified by infrared (IR) spectroscopy. The effects of monomer concentration, mole ratio of MVK to St, reaction time, reaction temperature, and initiator concentration on the graft terpolymerization were examined. Upon UV irradiation in the presence of oxygen, the MVES-containing carbonyl group showed photodegradable properties caused by Norrish type II reaction. The new IR characteristic peaks, such as carbonyl, vinyl, and hydroxy groups of the photodegraded MVES, increased with increasing UV irradiation time. The tensile strength and elongation at break of MVES after UV irradiation were lower than those of before UV irradiation. The color difference of the irradiated MVES was higher than that of EPDM. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1721–1727, 1998     

Acrylonitrile–styrene copolymer grafted onto ethylene–propylene–diene terpolymer

The two-phase structure of the acrylonitrile–styrene copolymer grafted onto ethylene–propylene–diene terpolymer (EPDM) was investigated using an electron microscope. It was found that the microstructure depends on the solvent system for graft copolymerization, separation of the graft copolymer, and the processing procedure. The graft EPDM phase forms the discontinuous phase in chlorobenzene and in the toluene–ethyl acetate mixed solvent, whereas it is the continuous phase in the hexane–ethyl acetate mixed solvent. The phase inversion of the rubber phase in the case of the latter is carried out partially in the separation procedure and completely in the processing procedure.     

Natural rubber‐g‐methyl methacrylate/poly(methyl methacrylate) blends

The grafting of the methyl methacrylate (MMA) monomer onto natural rubber using potassium persulfate as an initiator was carried out by emulsion polymerization. The rubber macroradicals reacted with MMA to form graft copolymers. The morphology of grafted natural rubber (GNR) was determined by transmission electron microscopy and it was confirmed that the graft copolymerization was a surface‐controlled process. The effects of the initiator concentration, reaction temperature, monomer concentration, and reaction time on the monomer conversion and grafting efficiency were investigated. The grafting efficiency of the GNR was determined by a solvent‐extraction technique. The natural rubber‐g‐methyl methacrylate/poly(methyl methacrylate) (NR‐g‐MMA/PMMA) blends were prepared by a melt‐mixing system. The mechanical properties and the fracture behavior of GNR/PMMA blends were evaluated as a function of the graft copolymer composition and the blend ratio. The tensile strength, tear strength, and hardness increased with an increase in PMMA content. The tensile fracture surface examined by scanning electron microscopy disclosed that the graft copolymer acted as an interfacial agent and gave a good adhesion between the two phases of the compatibilized blend. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 428–439, 2001     

Graft polymerization of styrene onto random ethylene–propylene diene monomer

The graft copolymerization of styrene (St) onto random ethylene–propylene diene monomer (EPDM) with benzoyl peroxide (BPO) and 2,2-azo-bis-isobutyronitrile (AIBN) as the initiator in solvent was studied. Results showed that BPO was superior to AIBN. The influence factors, such as reaction St and BPO, on the extent of graft were discussed. The existence of a grafted copolymer was verified by infrared spectra, NMR, and thin-laver chromatography. The grafted copolymer was characterized by thermally stimulated current. © 1996 John Wiley & Sons, Inc.     

Effect of the addition of acrylonitrile/ethylene–propylene–diene monomer (EPDM)/styrene graft copolymer on the morphology–properties relationships in poly(styrene‐co‐acrylonitrile)/EPDM rubber blends

Blends of poly(styrene‐co‐acylonitrile) (SAN) with ethylene–propylene–diene monomer (EPDM) rubber were investigated. An improved toughness–stiffness balance of the SAN/EPDM blend was obtained when an appropriate amount of acrylonitrile–EPDM–styrene (AES) graft copolymer was added, prepared by grafting EPDM with styrene–acrylonitrile copolymer, and mixed thoroughly with both of the two components of the blend. Morphological observations indicated a finer dispersion of the EPDM particles in the SAN/EPDM/AES blends, and particle size distribution became narrower with increasing amounts of AES. Meanwhile, it was found that the SAN/EPDM blend having a ratio of 82.5/17.5 by weight was more effective in increasing the impact strength than that of the 90/10 blend. From dynamic mechanic analysis of the blends, the glass‐transition temperature of the EPDM‐rich phase increased from ?53.9 to ?46.2°C, even ?32.0°C, for the ratio of 82.5/17.5 blend of SAN/EPDM, whereas that of the SAN‐rich phase decreased from 109.2 to 108.6 and 107.5°C with the additions of 6 and 10% AES copolymer contents, respectively. It was confirmed that AES graft copolymer is an efficient compatibilizer for SAN/EPDM blend. The compatibilizer plays an important role in connecting two phases and improving the stress transfer in the blends. Certain morphological features such as thin filament connecting and even networking of the dispersed rubber phase may contribute to the overall ductility of the high impact strength of the studied blends. Moreover, its potential to induce a brittle–ductile transition of the glassy SAN matrix is considered to explain the toughening mechanism. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1685–1697, 2004     

Amphiphilic styrene–butadiene–styrene triblock copolymer grafted with polyoxyethylene

A styrene–butadiene–styrene triblock copolymer (SBS) was grafted with polyoxyethylene via a ring‐opening reaction of an epoxidized styrene–butadiene– styrene triblock copolymer (ESBS) with monocarboxylic‐group‐terminated methoxypoly(ethylene glycol) (CMPEG). The latter was prepared through the esterification of methoxypoly(ethylene glycol) with maleic anhydride. The optimum conditions for the preparation of the graft copolymer were studied. The graft copolymer was characterized with Fourier transform infrared spectrophotometry. Its water absorbency, oil absorbency, emulsifying property, phase‐transfer catalysis property in the Williamson solid–liquid reaction, and use as a compatibilizer in the blending of SBS with oil‐resistant chlorohydrin rubber (CHR) were also studied. The optimum conditions were a CMPEG/epoxy group molar ratio of 1.5, an N,N‐dimethyl aniline/ESBS concentration of 5 wt %, and an ESBS concentration of 12–14 g/100 mL at 75–80°C for 10 h. The polyoxyethylene content could reach 0.27 mmol/g. The graft copolymer absorbed a certain amount of water, fairly resisted kerosene, and possessed good emulsifying and phase‐transfer catalysis properties, both of which were enhanced with increasing polyoxyethylene graft content. The graft copolymer could be used as a compatibilizer for a blend of SBS and CHR. A 3 wt % concentration of the graft copolymer based on a 50/50 blend could increase both the tensile strength and ultimate elongation of the blend about 1.7 times. The blend behaved like an oil‐resistant thermoplastic elastomer. Scanning electron microscopy demonstrated the improved compatibility of the two components by the graft copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of premade and in situ compatibilizers in polypropylene/ethylene–propylene–diene terpolymer thermoplastic elastomeric olefins and thermoplastic vulcanizates

During dynamic vulcanization of polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM) blends with dicumyl peroxide/triallyl cyanurate, there is a possibility of the generation of in situ graft links at the interface. Three potential compatibilizers (PP‐grafted EPDM, styrene–ethylenebutylene–styrene, and trans‐polyoctenamer) for PP/EPDM blends were first investigated as references to obtain a quantified insight into the effects to be expected from in situ graft links. Only the first compatibilizer showed some compatibilizing action in straight, unvulcanized blends, as evidenced by a slight increase in the tensile strength of the blend and a somewhat smaller EPDM particle size within the PP matrix. Also, dynamic mechanical testing, in particular, the glass‐transition temperatures of the PP and EPDM components, showed some signs of compatibilization. The PP‐grafted EPDM resembled most closely the structures of PP and EPDM. In the spectra obtained with high temperature, solid‐state NMR, there was an indication that PP–EPDM graft links were generated during the dynamic vulcanization process that still remained after the extraction of the free PP phase from the thermoplastic vulcanizate film. NMR relaxation experiments gave further evidence for the graft links formed in situ. In all cases, only qualitative indications could be achieved because of the extremely low number of graft links formed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3877–3888, 2006     

Synthesis of high rubber styrene–EPDM–acrylonitrile graft copolymer and its toughening effect on SAN

High rubber styrene–EPDM–acrylonitrile (AES) was prepared by the graft copolymerization of styrene (St) and acrylonitrile (AN) onto ethylene–propylene–diene terpolymer (EPDM) in n‐heptane/toluene cosolvent using benzoyl peroxide as an initiator. The effects of reaction conditions, such as reaction temperature, initiator concentration, EPDM content, the solvent component, and reaction time, on the graft copolymerization are discussed. In addition, according to the research on mechanical properties of the SAN/AES blend, a remarkable toughening effect of AES on SAN resin was found. By means of scanning electron microscopy, the toughening mechanism is proposed to be crazing initiation from rubber particles and shear deformation of SAN matrix. Uniform dispersion of rubber particles, as shown by transmission electron microscopy, is attributed to the good compatibility of SAN and AES. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 416–423, 2004     

Abrasion resistance of thermoplastic polyurethane materials blended with ethylene–propylene–diene monomer rubber

The effect of ethylene–propylene–diene monomer rubber (EPDM) as an additive on the abrasion resistance of a thermoplastic polyurethane (TPU) resin was investigated. The mechanical properties and microstructure of the resultant TPU/EPDM composites were evaluated, and the surface morphology of the composites after abrasion testing was examined. The results showed that the addition of EPDM greatly improved both the mechanical properties and abrasion resistance of the TPU resin. A TPU/EPDM composite with 8 wt % EPDM demonstrated the highest tensile strength, the largest elongation at break, and the best overall performance. The abrasion of this composite was 27 mg, whereas that of the pure resin was 73 mg. With the further addition of EPDM, the abrasion resistance of the resultant composites decreased, whereas the viscosity increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of styrene–ethylene–butylene–styrene triblock copolymer‐g‐polylactic acid copolymer and its potential application as a toughener for polylactic acid

The copolymer of styrene–ethylene–butylene–styrene triblock copolymer‐g‐polylactic acid (SEBS‐g‐PLA) was successfully prepared using a novel solvothermal synthetic method, in which the graft copolymerization of PLA and SEBS was simply performed in cholorform solution at 100–150°C with benzoyl peroxide (BPO) as initiator. The effect of various factors including the reaction temperature and time and the content of BPO and PLA on the graft copolymerization was investigated in detail. It is found that the optimal reaction condition for the grafted copolymers SEBS‐g‐PLA was 120°C for 5 h, while the optimal formulation of SEBS/PLA/BPO was 5 g/2 g/0.5 g in 30 mL chloroform. The properties and microstructures of the obtained SEBS‐g‐PLA copolymers were also studied. The tensile strength and elongation at break were higher than that of pure SEBS and improved with the increase of grafting degree. In addition, SEBS‐g‐PLA copolymer possessed two‐phase structure with vague phase boundaries. The as‐prepared SEBS‐g‐PLA copolymers can be used as the toughening component to improve the impact strength of PLA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Blends of poly(vinyl chloride) (PVC)/natural rubber‐g‐(styrene‐co‐methyl methacrylate) for improved impact resistance of PVC

To improve the mechanical properties of poly(vinyl chloride) (PVC), the possibility of combining PVC with elastomers was considered. Modification of natural rubber (NR) by graft copolymerization with methyl methacrylate (MMA) and styrene (St) was carried out by emulsion polymerization by using redox initiator to provide an impact modifier for PVC. The impact resistance, dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM) of St and MMA grafted NR [NR‐g‐(St‐co‐MMA)]/PVC (graft copolymer product contents of 5, 10, and 15%) blends were investigated as a function of the amount of graft copolymer product. It was found that the impact strength of blends was increased with an increase of the graft copolymer product content. DMA studies showed that NR‐g‐(St‐co‐MMA) has partial compatibility with PVC. SEM confirmed a shift from brittle failure to ductility with an increase graft copolymer content in the blends. The mechanical properties showed that NR‐g‐(St‐co‐MMA) interacts well with PVC and can also be used as an impact modifier for PVC. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1666–1672, 2004     

Graft copolymerization of styrene and acrylonitrile onto EPDM

Acrylonitrile–EPDM–styrene (AES) graft copolymers were synthesized by solution graft polymerization of styrene (St) and acrylonitrile (AN) onto EPDM in an n‐hexane/benzene solvent with benzoyl peroxide (BPO) as an initiator. The structure changes were studied by an FTIR spectrophotometer. The grafting parameters were calculated gravimetrically. The influence of the polymerization conditions, such as the reaction time, concentration of the initiator, EPDM content, and weight ratio of St/AN, on the structure of the products was investigated. It was found that a proper initiator concentration and EPDM content will give a high grafting ratio of the AES resin. The thermal property of the copolymer was studied using programmed thermogravimetric analysis (TGA). The results showed that the copolymer has a better heat‐resistant property than that of ABS, especially for the initial decomposition temperature (T_in) and the maximum weight loss rate temperature (T_max). Also, the mechanism of the graft reaction was discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 428–432, 2002     

Preparation and properties of ethylene–propylene–diene rubber/organomontmorillonite nanocomposites

Ethylene–propylene–diene rubber (EPDM)/organomontmorillonite (OMMT) nanocomposites were prepared with a maleic anhydride grafted EPDM oligomer as a compatibilizer via melt intercalation. X‐ray diffraction and transmission electron microscopy indicated that the silicate layers of OMMT were exfoliated and dispersed uniformly as a few monolayers in nanocomposites. The change in the crystallization behavior of the nanocomposites was examined. The nanocomposites exhibited great improvements in the tensile strength and tensile modulus. The incorporation of OMMT gave rise to a considerable reduction of tan δ and an increase in the storage modulus. Moreover, the solvent resistance of the nanocomposites increased remarkably. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 440–445, 2004