Poly(styrene)‐ and Poly(styrene‐co‐methyl methacrylate)‐graft‐hydrogenated natural rubber latex: Aspect on synthesis,properties, and compatibility

The undesirable properties of natural rubber (NR) can be improved via hydrogenation and graft copolymerization. Hydrogenated NR (HNR) latex was prepared via diimide reduction and then grafted with styrene (ST) or ST/methyl methacrylate (MMA) to form poly(ST)‐graft‐HNR (poly(ST)‐g‐HNR, GHNRS) or poly(ST‐co‐MMA)‐g‐HNR (GHNRSM), respectively. For the grafting of ST monomer onto HNR particles, the %monomer conversion and %grafting efficiency (%GE) were monitored as functions of %hydrogenation, monomer and initiator concentrations, temperature, and time. Under the optimum condition (HNR with 54.3% hydrogenation; 100 phr of ST, 1 phr of initiator at 50°C for 8 h), maximum %conversion and %GE of 44.6% and 36.9%, respectively, were achieved. Thermogravimetric analysis revealed that the HNR grafted with ST or ST/MMA had higher decomposition temperature than an ungrafted one. When these graft products were blended at 10% (w/w) with acrylonitrile‐butadiene‐styrene (ABS) resin, the GHNRS/ABS and GHNRSM/ABS composites exhibited the higher flexural strength and heat aging tolerance compared to the ungrafted HNR/ABS composite. Scanning electron microscopy (SEM) also showed the higher degree of homogeneity at the fractural surface, supporting the higher compatibility between the ABS and the GHNRS or GHNRSM phases in the blends. J. VINYL ADDIT. TECHNOL., 22:100–109, 2016. © 2014 Society of Plastics Engineers     

Studies on preparation and properties of vinyltriethoxysilane‐grafted styrene‐butadiene rubber

Graft polymerization of vinyltriethoxysilane (VTES) onto styrene‐butadiene rubber (SBR) was carried out in latex using benzoic peroxide (BPO) as an initiator. The concentration of VTES effecting on vulcanization characteristics, mechanical properties and thermal properties of VTES‐grafted SBR (SBR‐g‐VTES) were investigated. The grafting of VTES onto SBR and its pre‐crosslinking were confirmed by attenuated total teflectance‐Fourier transform infrared reflectance and proton nuclear magnetic resonance. The mechanism of graft polymerization was studied. The results revealed that the minimum torque, optimum cure time, tensile strength, thermal decomposition temperature, and glass transition temperature (T_g) all increased with the increasing concentration of VTES. But the grafting efficiency of VTES, rate of vulcanization, and elongation at break of the SBR‐g‐VTES decreased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Influence of functional groups on properties of styrene grafted NR using glutaraldehyde as curing agent

Natural rubber grafted polystyrene (NR‐g‐PS) and natural rubber grafted polystyrene‐co‐methyl methacrylate (NR‐g‐P(S‐co‐MMA)) were prepared by emulsion polymerization technique using tert‐BuHP‐TEPA as a redox initiator to improve the thermal and mechanical stability of NR. Additional peaks appear in the Fourier‐transform infrared spectra at 695 and 1,732 cm^?1 confirms the formation of graft polymerization. The existence of functional groups on the grafted NR was also clearly confirmed from the morphology obtained from transmission electron microscopy analysis. The effect of curing on the mechanical and thermal properties of grafted NR has also been studied. Glutaraldehyde was used as the curing agent for the grafted and ungrafted NRs throughout the entire course of investigation. It was found that curing of grafted NR samples enhanced tensile strength, modulus, hardness, and thermal stability. Grafted NR showed the tensile strength values of 12 and 17 MPa for NR‐g‐PS and NR‐g‐P(S‐co‐MMA), respectively. Enhancement in thermal stability of NR was confirmend from the activation energy of degradation calculated based on thermogravimetric analyzer. The value of activation energy for NR (135.13 kJ/mol) was found to be increased to 147.89 kJ/mol (NR‐g‐PS) and 151.6 kJ/mol (NR‐g‐P(S‐co‐MMA)). The overall properties of NR have been strongly affected by the interaction and chain bundling between functional groups present in the grafted copolymer and the unsaturated chains in its structure. J. VINYL ADDIT. TECHNOL., 25:339–346, 2019. © 2019 Society of Plastics Engineers     

Morphology and mechanical properties of ABS blends prepared from emulsion‐polymerized PB‐g‐SAN impact modifier with AIBN as initiator

A series of PB‐g‐SAN impact modifiers (polybutadiene particles grafted by styrene and acrylonitrile) are synthesized by seed emulsion copolymerization initiated by oil‐soluble initiator, azobisiobutyronitrile (AIBN). The ABS blends are obtained by mixing SAN resin with PB‐g‐SAN impact modifiers. The mechanical behavior and the phase morphology of ABS blends are investigated. The graft degree (GD) and grafting efficiency (GE) are investigated, and the high GD shows that AIBN has a fine initiating ability in emulsion grafting of PB‐g‐SAN impact modifiers. The morphology of the rubber particles is observed by the transmission electron microscopy (TEM). The TEM photograph shows that the PB‐g‐SAN impact modifier initiated by AIBN is more likely to form subinclusion inside the rubber particles. The dynamic mechanical analysis on ABS blends shows that the subinclusion inside the rubber phase strongly influences the T_g, maximum tan δ, and the storage modulus of the rubber phase. The mechanical test indicates that the ABS blends, which have the small and uniform subinclusions dispersed in the rubber particles, have the maximum impact strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Preparation and graft‐copolymerization of hydrogenated natural rubber in latex stage

Preparation and graft‐copolymerization of hydrogenated natural rubber are performed in latex stage after removal of proteins from the rubber with urea and surfactant. Hydrogenation of deproteinized natural rubber (DPNR) latex is carried out with palladium catalyst under hydrogen atmosphere. The hydrogenated DPNR (HDPNR) is crosslinked with a peroxide followed by graft‐copolymerization of styrene (Sty) and acrylonitrile (AN) in latex stage in order to prepare a graft‐copolymer of crosslinked HDPNR with poly(Sty‐co‐AN) (HDPNR‐graft‐PSAN). Characterization of the products is performed by nuclear magnetic resonance spectroscopy. The conversion of hydrogenation is investigated with respect to the catalyst feed, acidity (pH), and dry rubber content. In the resulting HDPNR‐graft‐PSAN, mole fraction of AN and Sty is 1.4 and 5.8 mol %, respectively. The graft‐copolymer is used to improve properties of PSAN as an impact modifier. The Charpy impact strength of crosslinked HDPNR‐graft‐PSAN/PSAN is about eight times as high as that of PSAN. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42435.     

Thermal and flame resistance properties of natural rubber‐g‐poly‐(dimethyl(methacryloyloxymethyl)phosphonate)

Natural rubber grafted with poly(dimethyl(methacryloyloxymethyl)phosphonate) (i.e., NR‐g‐PDMMMP) was prepared in latex medium via photopolymerization. Thermal and flame resistance properties of the NR‐g‐PDMMMP prepared with various levels of grafted PDMMMP or grafting rate (GR) were investigated. Thermal behaviors were investigated by thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). It was found that the graft copolymer exhibited phase separation with double T_g values. A shift of T_gs toward each other was observed with increasing GR, which indicated tendency to become a single phase material. Increasing GRs also caused increasing heat and flame resistance with increasing degradation temperature and level of char residue. Furthermore, increasing level of limited oxygen index (LOI) and decreasing burning rate were observed with increasing the GR. This is attributed to increasing content of char residue of the phosphorus compound, which acted as the thermal insulation and a barrier of oxygen to transfer to the burning materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of poly(ethylene‐co‐vinyl acetate) additive on mechanical properties of maleic anhydride‐grafted acrylonitrile butadiene styrene for coating applications

The Izod impact strength of maleic anhydride‐grafted acrylonitrile butadiene styrene (MA‐g‐ABS) copolymer has been improved by the use of rubbery poly(ethylene‐co‐vinyl acetate) (EVA). The MA‐g‐ABS is prepared by an internal mixer using dicumyl peroxide as free radical initiator, and the grafting degree was determined using back‐titration method. The amount of EVA is optimized by evaluating the Izod impact strength, tensile, and flexural properties of the samples. Addition of 6% EVA into MA‐g‐ABS system improved the Izod impact strength and tensile strength by 18% and 35%, respectively. The miscibility of EVA in ABS and MA‐g‐ABS matrices has been observed using differential scanning calorimetry and scanning electron microscopy techniques. The enhanced adhesion property exhibited by MA‐g‐ABS/EVA systems promises it as a good candidate for thermoplastic coating applications on aluminum substrates. J. VINYL ADDIT. TECHNOL., 25:287–295, 2019. © 2018 Society of Plastics Engineers     

Morphological,mechanical properties,and fracture behavior of bulk‐made ABS resins toughened by high‐cis polybutadiene rubber

Acrylonitrile‐butadiene‐styrene (ABS) resins with various rubber contents were prepared by applying nickel catalyzed high‐cis polybutadiene rubber (BR9004) as toughening agent via bulk polymerization. The influence of rubber content and its characteristics on the morphology, mechanical properties, and fracture mechanisms of ABS resins were investigated. The relevant performance parameters were also evaluated and compared with a commercial injection grade resin (ABS‐8434). The results show that each synthesized resin generally contains some irregular microsized particles with a certain amount of subinclusions besides the analogous “sea‐island” morphology to ABS‐8434. The subinclusions considerably enhance the volume fraction of rubber phase; this leads to an increasing maximum loss tangent (tan δ) value, a decreasing storage modulus and glass transition temperature (T_g) of rubber phase. Besides, the higher grafting degree can not only produce a higher T_g of grafted copolymer but also improve the compatibility of rubber phase with matrix. Based on the performance measurements andfractography, the final product with a rubber content of 9.3% reveals ductile fracture behavior and excellent comprehensive properties far superior to ABS‐8434 due to combined shear yielding and massive crazing. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Grafting of poly(vinyl alcohol) on natural rubber latex particles

Poly(vinyl alcohol) (PVA) was grafted on natural rubber (NR) latex particles (NR‐g‐PVA) using potassium persulfate to generate active radicals on both NR particle surface as well as PVA molecules. ¹H‐ and ¹³C‐nuclear magnetic resonance spectroscopy suggested a possibly chemical attachment of PVA on the NR. The amount of graft‐PVA expressed in term of grafting percentage (%G) increased almost linearly with the amount of PVA adding to the NR latex. Measuring by dynamic light scattering, the particle size of NR‐g‐PVA particles was larger than the size of unmodified NR, also it increased with the molecular weight and %G of PVA. Transmission electron microscopy images of the NR‐g‐PVA latex particles revealed that the size of PVA‐grafted NR particle was enlarged by a layer of graft‐PVA surrounding the NR particle. Given by the graft‐PVA layer surrounding NR particles, the NR‐g‐PVA latex particles possessed better colloidal stability as lowering pH compared with the unmodified NR latex. Comparing with unmodified NR particles, the electrophoretic mobility of NR‐g‐PVA particles was lower due to the presence of graft‐PVA that shifted the shear plane further away from the surface of the particles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effects of the polybutadiene/poly(styrene‐co‐acrylonitrile) ratio in a polybutadiene‐g‐poly(styrene‐co‐acrylonitrile) impact modifier on the morphology and mechanical behavior of acrylonitrile–butadiene–styrene blends

Polybutadiene‐g‐poly(styrene‐co‐acrylonitrile) (PB‐g‐SAN) impact modifiers with different polybutadiene (PB)/poly(styrene‐co‐acrylonitrile) (SAN) ratios ranging from 20.5/79.5 to 82.7/17.3 were synthesized by seeded emulsion polymerization. Acrylonitrile–butadiene–styrene (ABS) blends with a constant rubber concentration of 15 wt % were prepared by the blending of these PB‐g‐SAN copolymers and SAN resin. The influence of the PB/SAN ratio in the PB‐g‐SAN impact modifier on the mechanical behavior and phase morphology of ABS blends was investigated. The mechanical tests showed that the impact strength and yield strength of the ABS blends had their maximum values as the PB/SAN ratio in the PB‐g‐SAN copolymer increased. A dynamic mechanical analysis of the ABS blends showed that the glass‐transition temperature of the rubbery phase shifted to a lower temperature, the maximum loss peak height of the rubbery phase increased and then decreased, and the storage modulus of the ABS blends increased with an increase in the PB/SAN ratio in the PB‐g‐SAN impact modifier. The morphological results of the ABS blends showed that the dispersion of rubber particle in the matrix and its internal structure were influenced by the PB/SAN ratio in the PB‐g‐SAN impact modifiers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2165–2171, 2005     

Use of natural rubber‐g‐polystyrene as a compatibilizer in casting natural rubber/polystyrene blend films

Natural rubber/polystyrene (NR/PS) blend films with weight ratios of 70/30, 60/40, and 50/50 were prepared using polystyrene grafted natural rubber copolymers (NR‐g‐PS) as the compatibilizer. Copolymers with molar ratios of 90/10, 80/20, and 70/30 were synthesized via emulsion copolymerization using tert‐butyl hydroperoxide/tetraethylene pentamine as an initiator. The copolymers were subsequently added into the blends at 0, 5, 10, 15, 20, 25, and 30 phr. The mixtures were cast into films by the solution‐casting method using toluene as the casting solvent. Mechanical and morphological properties of the prepared films were investigated. The film prepared from 80/20 NR‐g‐PS showed higher tensile and tear strength, as well as finer domain size of the dispersed phase, than those prepared from 90/10 and 70/30 NR‐g‐PS. However, the mechanical properties of the films were decreased at high loading of the copolymers. In addition, themogravimetric analysis revealed that weight loss was decreased upon introduction of the compatibilizer. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 826–831, 2005     

Influences of the grafting percentage of natural rubber‐graft‐poly(2‐hydroxyethyl acrylate) on properties of its vulcanizates

The graft copolymerization of 2‐hydroxyethyl acrylate (HEA) monomer onto natural rubber (NR) latex was successful using cumene hydroperoxide and tetraethylene pentamine as redox initiators. The grafting of poly(2‐hydroxyethyl acrylate) (PHEA) on the NR particles was confirmed by Fourier transform infrared spectroscopy, ¹H NMR spectroscopy and TEM. The NR‐g‐PHEA with various grafting percentages (0%, 8.7%, 14.3% and 18.7%) was compounded on a two‐roll mill with a sulfur vulcanization system. The effects of grafting percentage on the cure characteristics, dielectric properties, thermal properties and physical properties of NR‐g‐PHEA vulcanizates were investigated. It was found that increased grafting caused NR‐g‐PHEA vulcanizates to have reduced water contact angle, scorch time and cure time, while the dielectric constant and dissipation factor increased. The NR‐g‐PHEA vulcanizate with 8.7% grafting exhibited the highest delta torque (M_H ? M_L), crosslink density, tensile strength, moduli at 100%, 200% and 300% strains, and hardness, with insignificant loss of elongation at break in comparison to the other cases. © 2018 Society of Chemical Industry     

Deformation mechanism of polystyrene toughened with sub‐micrometer monodisperse rubber particles

Core–shell polybutadiene‐graft‐polystyrene (PB‐g‐PS) rubber particles with different ratios of polybutadiene to polystyrene were prepared by emulsion polymerization through grafting styrene onto polybutadiene latex. The weight ratio of polybutadiene to polystyrene ranged from 50/50 to 90/10. These core‐shell rubber particles were then blended with polystyrene to prepare PS/PB‐g‐PS blends with a constant rubber content of 20 wt%. PB‐g‐PS particles with a lower PB/PS ratio (≤70/30) form a homogeneous dispersion in the polystyrene matrix, and the Izod notched impact strength of these blends is higher than that of commercial high‐impact polystyrene (HIPS). It is generally accepted that polystyrene can only be toughened effectively by 1–3 µm rubber particles through a toughening mechanism of multiple crazings. However, the experimental results show that polystyrene can actually be toughened by monodisperse sub‐micrometer rubber particles. Scanning electron micrographs of the fracture surface and stress‐whitening zone of blends with a PB/PS ratio of 70/30 in PB‐g‐PS copolymer reveal a novel toughening mechanism of modified polystyrene, which may be shear yielding of the matrix, promoted by cavitation. Subsequently, a compression‐induced activation method was explored to compare the PS/PB‐g‐PS blends with commercial HIPS, and the result show that the toughening mechanisms of the two samples are different. Copyright © 2006 Society of Chemical Industry     

Modification of acrylonitrile‐butadiene‐styrene terpolymer by graft copolymerization with maleic anhydride in the melt. II. Properties and phase behavior

The graft copolymerization of maleic anhydride (MAH) onto acrylonitrile‐butadiene‐styrene terpolymer (ABS) using dicumyl peroxide and benzoyl peroxide as the binary initiator and styrene as the comonomer in the molten state was described. The properties and phase morphologies of the modified products (ABS‐g‐MAH) were studied. The results indicate that the melt flow index (MFI) of ABS‐g‐MAH increases with the increase of MAH content, the initiator concentration, and the screw speed, whereas the MFI decreases with the increase of temperature. The impact strength and the percentage elongation of ABS‐g‐MAH both decreased and the tensile strength of ABS‐g‐MAH increased slightly as the grafting degree increased. The phase inversion behavior of the modified product was observed by transmission electron microscopy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2834–2839, 2004     

Influences of the phenolic curative content and blend proportions on the properties of dynamically vulcanized natural rubber/acrylonitrile–butadiene–styrene blends

The vulcanization of natural rubber (NR)‐blended acrylonitrile–butadiene–styrene (ABS) was carried out with a phenolic curing agent by a melt‐mixing process. The NR compound was first prepared before blending with ABS. The effects of the phenolic curative contents (10, 15, and 20 phr) and blend proportions (NR/ABS ratio = 50 : 50, 60 : 40, and 70 : 30) on the mechanical, dynamic, thermal, and morphological properties of the vulcanized NR/ABS blends were investigated. The tensile strength and hardness of the blends increased with increasing ABS content, whereas the elongation at break decreased. The strength property resulting from the thermoplastic component and the vulcanized NR was an essential component for improving the elasticity of the blends. These blends showed a greater elastic response than the neat ABS. The thermal stability of the blends increased with increasing ABS component. Scanning electron micrographs of the blends showed a two‐phase morphology system. The vulcanized 60 : 40 NR/ABS blend with 15‐phr phenolic resin showed a uniform styrene‐co‐acrylonitrile phase dispersed in the vulcanized NR phase; it provided better dispersion between the NR and ABS phases, and this resulted in superior elastic properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42520.     

Properties and morphologies of elastomer blends modified with EPDM‐g‐poly[2‐dimethylamino ethylmethacrylate]

The graft copolymerization of 2‐dimethylamino ethylmethacrylate (DMAEMA) onto ethylene propylene diene mononer rubber (EPDM) was carried out in toluene via solution polymerization technique at 70°C, using dibenzoyl peroxide as initiator. The synthesized EPDM rubber grafted with poly[DMAEMA] (EPDM‐g‐PDMAEMA) was characterized with ¹H‐NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). The EPDM‐g‐PDMAEMA was incorporated into EPDM/butadiene acrylonitrile rubber (EPDM/NBR) blend with different blend ratios, where the homogeneity of such blends was examined with scanning electron microscopy and DSC. The scanning electron micrographs illustrate improvement of the morphology of EPDM/NBR rubber blends as a result of incorporation of EPDM‐g‐PDMAEMA onto that blend. The DSC trace exhibits one glass transition temperature (T_g) for EPDM/NBR blend containing EPDM‐g‐PDMAEMA, indicating improvement of homogeneity. The physico‐mechanical properties after and before accelerated thermal aging of the homogeneous, and inhomogeneous EPDM/NBR vulcanizates with different blend ratios were investigated. The physico‐mechanical properties of all blend vulcanizates were improved after and before accelerated thermal aging, in presence of EPDM‐g‐PDMAEMA. Of all blend ratios under investigation EPDM/NBR (75/25) blend possesses the best physico‐mechanical properties together with the best (least) swelling (%) in brake fluid. Swelling behavior of the rubber blend vulcanizates in motor oil and toluene was also investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of sub‐micrometer core–shell rubber particles with 1,2‐azobisisobutyronitrile as initiator and deformation mechanisms of modified polystyrene under various conditions

BACKGROUND: Sub‐micrometer core‐shell polybutadiene‐graft‐polystyrene (PB‐g‐PS) copolymers with various ratios of polybutadiene (PB) core to polystyrene (PS) shell were synthesized by emulsion grafting polymerization with 1,2‐azobisisobutyronitrile (AIBN) as initiator. These graft copolymers were blended with PS to prepare PS/PB‐g‐PS with a rubber content of 20 wt%. The mechanical properties, morphologies of the core‐shell rubber particles and deformation mechanisms under various conditions were investigated. RESULTS: Infrared spectroscopic analysis confirmed that PS could be grafted onto the PB rubber particles. The experimental results showed that a specimen with a ‘cluster’ dispersion state of rubber particles in the PS matrix displayed better mechanical properties. Transmission electron micrographs suggested that crazing only occurred from rubber particles and extended in a bridge‐like manner to neighboring rubber particles parallel to the equatorial plane at a high speed for failure specimens, while the interaction between crazing and shear yielding stabilized the growing crazes at a low speed in tensile tests. CONCLUSION: AIBN can be used as an initiator in the graft polymerization of styrene onto PB. The dispersion of rubber particles in a ‘cluster’ state leads to better impact resistance. The deformation mechanism in impact tests was multi‐crazing, and crazing and shear yielding absorbed the energy in tensile experiments. Copyright © 2009 Society of Chemical Industry     

Effects of ABS‐g‐MAH on mechanical properties and compatibility of ABS/PC alloy

The effects of a compatibilizer, namely, an acrylonitrile–butadiene–styrene copolymer (ABS) grafted with maleic anhydrade (MAH) (ABS‐g‐MAH), on the mechanical properties and morphology of an ABS/polycarbonate (PC) alloy were studied The results showed that a small quantity of ABS‐g‐MAH has a very good influence on the notched Izod impact strength of the ABS/PC alloy without compromising other properties such as the tensile strength, flexural strength, and Vicat softening temperature (VST). The impact strength of the ABS/PC alloy, to a great extent, depends on the loading of ABS‐g‐MAH and the degree of grafting (DG) of MAH in the ABS‐g‐MAH. DSC analysis and SEM observation confirmed that ABS‐g‐MAH could significantly improve the compatibility of the ABS/PC alloy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 831–836, 2001     

Functionalization of styrene–butadiene rubber with meta‐pentadecenyl phenol for better processing: A multifunctional additive and renewable resource

Meta‐pentadecenyl phenol, a nonisoprenoid phenolic lipid, is a renewable agricultural resource and also a byproduct of the cashew industry; it is popularly known as cardanol. This study throws light on the grafting of cardanol, which has been established as a multifunctional additive for natural rubber, onto the main‐chain backbone of styrene–butadiene rubber (SBR), a synthetic polymer used to imbibe the multifunctional properties of the former, such as those of a plasticizer, curing promoter, process aid, and antioxidant, into the latter. The grafting was carried out in the solution stage on a trial basis with a peroxide catalyst, and all of the grafting parameters were optimized with a Taguchi methodology. The grafting of cardanol onto the SBR backbone was successfully confirmed by UV–visible spectroscopy, Fourier transform infrared spectroscopy, and NMR analysis. Thermal analysis of the cardanol‐grafted styrene–butadiene rubber (C‐g‐SBR) revealed a higher thermal stability and better plasticizing effect than that those found in the virgin SBR. The rheological properties of the grafted rubber indicated the improvement of the pseudo‐plastic (shear‐thinning) nature compared to that in gum SBR. The unfilled C‐g‐SBR vulcanizates exhibited physicomechanical properties comparable to 5‐phr processing‐oil‐containing SBR [oil‐plasticized styrene–butadiene rubber (OPSBR)] vulcanizates. The carbon‐black‐filled C‐g‐SBR vulcanizates exhibited improved plasticization, a faster curing rate, easy processability, and better physicomechanical properties compared to the 5‐phr OPSBR vulcanizates. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45150.     

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