Conductivity and structure of melt‐processed polyaniline binary and ternary blends

In the present study, conductive binary and ternary blends containing polyaniline (PANI) were developed through melt blending. The binary blends' investigation focused on the morphology, in light of the components' interaction, and the resulting electrical conductivity. Similar solubility parameters of a given doped PANI and a matrix polymer lead to dispersion of fine PANI particles within the matrix, and to formation of conducting paths at low PANI contents. A plasticizer acting also as a compatibilizer improves the matrix polymer/PANI interactions. In ternary blends consisting of PANI and two immiscible polymers, the PANI preferrentially locates in one of the components, affecting the blend's morphology. This “concentrating” effect leads to relatively high electrical conductivity at a low PANI content. The electrical conductivity of the studied ternary blends is almost independent of the components' sequence of addition into the hot melt mixing device, exhibiting the selectivity of PANI towards one of the components. Copyright © 2000 John Wiley & Sons, Ltd.     

Effect of organoclay loading and electron beam irradiation on the physico‐mechanical properties of low‐density polyethylene/ethylene‐vinyl acetate blend

The influence of electron beam (EB) irradiation and organoclay (OC) loading on the properties of low‐density polyethylene (LDPE)/ethylene‐vinyl acetate (EVA) blends was investigated. The samples were subjected to the EB irradiation with the dose values of 50 and 250 kGy. X‐ray diffraction (XRD), gel content, mechanical, thermal, and electrical properties were utilized to analyze the characteristics of the LDPE/EVA blends with and without OC at different irradiation dosages. Gel content analysis showed that the OC promotes considerably the insoluble part so that the LDPE/EVA blends filled with OC become fully crosslinked at 250 kGy; possibly through the formation of further crosslinks between OC and polymer chains. The samples irradiated by EB showed enhanced mechanical properties due to the formation of three‐dimensional networks. In addition, thermogravimetric analysis indicated that combined OC loading and radiation‐induced crosslinking improved thermal stability of LDPE/EVA blends considerably. Copyright © 2011 John Wiley & Sons, Ltd.     

Morphology and mechanical properties of blown films of a low‐density polyethylene/linear low‐density polyethylene blend

The morphologies of films blown from a low‐density polyethylene (LDPE), a linear low‐density polyethylene (LLDPE), and their blend have been characterized and compared using transmission electron microscopy, small‐angle X‐ray scattering, infrared dichroism, and thermal shrinkage techniques. The blending has a significant effect on film morphology. Under similar processing conditions, the LLDPE film has a relatively random crystal orientation. The film made from the LDPE/LLDPE blend possesses the highest degree of crystal orientation. However, the LDPE film has the greatest amorphous phase orientation. A mechanism is proposed to account for this unusual phenomenon. Cocrystallization between LDPE and LLDPE occurs in the blowing process of the LDPE and LLDPE blend. The structure–property relationship is also discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 507–518, 2002; DOI 10.1002/polb.10115     

Characterization of an unsaturated low‐density polyethylene

This study concerns a new group of low‐density polyethylenes (LDPEs)—unsaturated LDPE. The new LDPE is a copolymer between ethylene and 1,9‐decadiene and was polymerized in a commerical high‐pressure tubular reactor. The diene copolymerized with one double bond, leaving the other unreacted as a pendant side group. This yielded a copolymer containing a higher number of vinyl groups than ordinary LDPE. Fractionation of the copolymer and determination of the number of unsaturated structures in the different fractions by Fourier transform infrared spectroscopy revealed that the diene is homogeneously incorporated along the molar‐mass distribution curve. It is also possible to obtain copolymers with a varying vinyl content, without drastic changes in molar mass or molar‐mass distribution, by a controlled addition of 1,9‐decadiene to the reactor. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2974–2984, 2003     

Stabilization of a cocontinuous phase morphology by a tapered diblock or triblock copolymer in polystyrene‐rich low‐density polyethylene/polystyrene blends

The stability against the thermal annealing of a cocontinuous two‐phase morphology developed in polystyrene (PS)/low‐density polyethylene (LDPE) blends containing 80 wt % PS was investigated. Blends containing 1, 5, and 10 wt % of a tapered diblock poly(styrene‐block‐hydrogenated butadiene) (P(S‐b‐hB)) or triblock poly(styrene‐block‐hydrogenated butadiene‐block‐styrene) (P(S‐hB‐S)) copolymer were melt‐blended with roll‐mill mixing equipment. The efficiency of each of the two copolymers in stabilizing against coalescence the cocontinuous morphology was examined. The tensile properties of the resulting blends, annealed and nonannealed, were also examined in relation to the morphology induced by thermal annealing. The phase morphology was studied by optical and scanning electron microscopy. With computer‐aided image analysis, it was possible to obtain a measurable characteristic parameter to quantify the cocontinuous phase morphology. When it was necessary, the extraction of one phase with a selective solvent was performed. Although the observed differences were subtle, the tapered diblock exhibited a more efficient compatibilizing activity than the triblock copolymer, particularly at a low concentration of about 2 wt %. The superiority of the tapered diblock over the triblock might be due to its ability to quantitatively locate at the LDPE/PS interface and consequently form a more efficient barrier against the subsequent breakup of the elongated structures of the cocontinuous phase morphology. The tensile properties of the triblock‐modified blends were more sensitive to thermal annealing than the tapered‐modified ones. This deficiency was ascribed to the phase morphology coarsening of the dispersed polyethylene phase. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 202–216, 2003     

Selective distribution,reinforcement, and toughening roles of MWCNTs in immiscible polypropylene/ethylene‐co‐vinyl acetate blends

Polypropylene/ethylene‐co‐vinyl acetate (PP/EVA) nanocomposites with functionalized multiwalled carbon nanotubes (FMWCNTs) have been prepared. The dissolution experiment, transmission electronic microscope, and scanning electronic microscope characterizations prove that, in the nanocomposites with sea–island morphology, although some FMWCNTs are observed in both PP and EVA phases, most of FMWCNTs distribute at the interface; however, in the nanocomposites with cocontinuous morphology, FMWCNTs mainly distribute in EVA phase. Further results based on (differential scanning calorimetry) measurements show that the different dispersion states of FMWCNTs, which are resulted by the different melt blending sequences, result in the different crystallization behaviors of PP matrix. The mechanical measurements show that FMWCNTs exhibit apparent reinforcement and toughening effects for immiscible PP/EVA blends, and such effects are greatly dependent upon the blending sequences. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1882–1892, 2010     

Morphology,structure, and properties of in situ compatibilized linear low‐density polyethylene/polystyrene and linear low‐density polyethylene/high‐impact polystyrene blends

Blends of linear low‐density polyethylene (LLDPE) with polystyrene (PS) and blends of LLDPE with high‐impact polystyrene (HIPS) were prepared through a reactive extrusion method. For increased compatibility of the two blending components, a Lewis acid catalyst, aluminum chloride (AlCl₃), was adopted to initiate the Friedel–Crafts alkylation reaction between the blending components. Spectra data from Raman spectra of the LLDPE/PS/AlCl₃ blends extracted with tetrahydrofuran verified that LLDPE segments were grafted to the para position of the benzene rings of PS, and this confirmed the graft structure of the Friedel–Crafts reaction between the polyolefin and PS. Because the in situ generated LLDPE‐g‐PS and LLDPE‐g‐HIPS copolymers acted as compatibilizers in the relative blending systems, the mechanical properties of the LLDPE/PS and LLDPE/HIPS blending systems were greatly improved. For example, after compatibilization, the Izod impact strength of an LLDPE/PS blend (80/20 w/w) was increased from 88.5 to 401.6 J/m, and its elongation at break increased from 370 to 790%. For an LLDPE/HIPS (60/40 w/w) blend, its Charpy impact strength was increased from 284.2 to 495.8 kJ/m². Scanning electron microscopy micrographs showed that the size of the domains decreased from 4–5 to less than 1 μm, depending on the content of added AlCl₃. The crystallization behavior of the LLDPE/PS blend was investigated with differential scanning calorimetry. Fractionated crystallization phenomena were noticed because of the reduction in the size of the LLDPE droplets. The melt‐flow rate of the blending system depended on the competition of the grafting reaction of LLDPE with PS and the degradation of the blending components. The degradation of PS only happened during the alkylation reaction between LLDPE and PS. Gel permeation chromatography showed that the alkylation reaction increased the molecular weight of the blend polymer. The low molecular weight part disappeared with reactive blending. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1837–1849, 2003     

Direct synthesis of linear low‐density polyethylene of ethylene/1‐hexene from ethylene with a tandem catalytic system in a single reactor

Tandem catalysis offers a promising synthetic route to the production of linear low‐density polyethylene. This article reports the use of homogeneous tandem catalytic systems for the synthesis of ethylene/1‐hexene copolymers from ethylene stock as the sole monomer. The reported catalytic systems employ the tandem action between an ethylene trimerization catalyst, (η⁵‐C₅H₄CMe₂C₆H₅)TiCl₃ ( 1 )/modified methylaluminoxane (MMAO), and a copolymerization metallocene catalyst, [(η⁵‐C₅Me₄)SiMe₂(^tBuN)]TiCl₂ ( 2 )/MMAO or rac‐Me₂Si(2‐MeBenz[e]Ind)₂ZrCl₂ ( 3 )/MMAO. During the reaction, 1 /MMAO in situ generates 1‐hexene with high activity and high selectivity, and simultaneously 2 /MMAO or 3 /MMAO copolymerizes ethylene with the produced 1‐hexene to generate butyl‐branched polyethylene. We have demonstrated that, by the simple manipulation of the catalyst molar ratio and polymerization conditions, a series of branched polyethylenes with melting temperatures of 60–128 °C, crystallinities of 5.4–53%, and hexene percentages of 0.3–14.2 can be efficiently produced. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4327–4336, 2004     

Block balance in hydrogenated polybutadiene‐b‐polymethylmethacrylate diblock copolymer for efficient interfacial activity in low‐density polyethylene/polymethylmethacrylate blend: Phase morphology development

The objective of the present study was to determine the best molecular balance between the two hydrogenated polybutadiene (HPB) and polymethylmethacrylate (PMMA) blocks that promotes an HPB‐b‐PMMA diblock copolymer with efficient compatibilization activity in a low‐density polyethylene (LDPE)/PMMA immiscible blend. The model blend selected, LDPE/PMMA, is “more immiscible” than the LDPE/polystyrene pair largely reported in open literature. The blends having a composition of 80LDPE/20PMMA exhibit a droplet‐in‐matrix phase morphology whereas in 20LDPE/80PMMA a co‐continuous phase morphology was developed. In the droplet‐in‐matrix phase morphology, the emulsifying efficiency of the copolymer was evaluated based on the maximum reduction of the PMMA droplet size it is able to promote. Whereas, in the co‐continuous phase morphology, the copolymer was evaluated based on its ability to stabilize the maximum phase co‐continuity. The sequences of the best emulsifying copolymer revealed are not symmetrical. An HPB‐b‐PMMA where the ratio of molar mass of the blocks, _HPB/ _PMMA, is within 1.8–1.95 exhibits a much better interfacial activity in LDPE/PMMA blends than a copolymer of much lower ratio (longer PMMA block). This is ascribed to the much higher interactions (cohesive energy density) encountered in PMMA (PMMA of the copolymer and PMMA phase of the blend) compared with the LDPE side (HPB of the copolymer and LDPE phase of the blend). © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 837–848, 2005     

Photocrosslinking and related properties of intumescent flame‐retardant LLDPE/EVA/IFR blends

The photoinitiated crosslinking of halogen‐free flame retarded linear low density polyethylene/poly(ethylene‐co‐vinyl acetate) blends (LLDPE/EVA) with the intumescent flame retardant (IFR) of phosphorous‐nitrogen compound (NP) in the presence of photoinitiator and crosslinker and their characterization of related properties have been investigated by gel determination, heat extension test, cone calorimeter test (CCT), thermogravimetric analysis (TGA), Fourier transfer infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), mechanical properties measurements, limiting oxygen index (LOI), UL‐94, and water resistance test. The data from the gel content and heat extension rate (HER) show that the LLDPE/EVA/IFR blends filled with NP are readily crosslinked to a gel content of above 75% and the HER values reach about 50% by UV‐irradiation of 5 sec under suitable amount of photoinitiator and crosslinker. The data obtained from the CCT and LOI indicate that photocrosslinking can considerably decrease the heat release rates (HRR) by 10–15%, prolongate the combustion time, and increase two LOI values for the LLDPE/EVA/NP blends UV irradiated for 5 sec. The results from TGA and the dynamic FTIR spectra give the evidence that the photocrosslinked LLDPE/EVA/NP samples show slower thermal degradation rate and higher thermo‐oxidative degradation temperature than the uncrosslinked LLDPE/EVA/NP samples. The morphological structures of charred residues observed by SEM give the positive evidence that the compact charred layers formed from the photocrosslinked LLDPE/EVA/NP samples play an important role in the enhancement of flame retardant and thermal properties. The data from the mechanical tests and water‐resistant measurements show that photocrosslinking can considerably improve the mechanical and water‐resistant properties of LLDPE/EVA/NP samples. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] on the charge distributions of low‐density polyethylene/polystyrene blends

The effect of the triblock copolymer poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] (SEBS) on the formation of the space charge of immiscible low‐density polyethylene (LDPE)/polystyrene (PS) blends was investigated. Blends of 70/30 (wt %) LDPE/PS were prepared through melt blending in an internal mixer at a blend temperature of 220 °C. The amount of charge that accumulated in the 70% LDPE/30% PS blends decreased when the SEBS content increased up to 10 wt %. For compatibilized and uncompatibilized blends, no significant change in the degree of crystallinity of LDPE in the blends was observed, and so the effect of crystallization on the space charge distribution could be excluded. Morphological observations showed that the addition of SEBS resulted in a domain size reduction of the dispersed PS phase and better interfacial adhesion between the LDPE and PS phases. The location of SEBS at a domain interface enabled charges to migrate from one phase to the other via the domain interface and, therefore, resulted in a significant decrease in the amount of space charge for the LDPE/PS blends with SEBS. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2813–2820, 2004     

Transport properties of crosslinked acrylonitrile butadiene rubber/poly(ethylene‐co‐vinyl acetate) blends

The diffusion and transport of organic solvents through crosslinked nitrile rubber/poly(ethylene‐co‐vinyl acetate) (NBR/EVA) blends have been studied. The diffusion of cyclohexanone through these blends was studied with special reference to blend composition, crosslinking systems, fillers, filler loading, and temperature. At room temperature the mechanism of diffusion was found to be Fickian for cyclohexanone–NBR/EVA blend systems. However, a deviation from the Fickian mode of diffusion is observed at higher temperature. The transport coefficients, namely, intrinsic diffusion coefficient (D*), sorption coefficient (S), and permeation coefficient (P) increase with the increase in NBR content. The sorption data have been used to estimate the activation energies for permeation and diffusion. The van't Hoff relationship was used to determine the thermodynamic parameters. The affine and phantom models for chemical crosslinks were used to predict the nature of crosslinks. The experimental results were compared with the theoretical predictions. The influence of penetrants transport was studied using dichloromethane, chloroform, and carbon tetrachloride. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1815–1831, 1999     

Effect of the coupling agent's reactivity on the shrinkability of the blends consisting of grafted low‐density polyethylene and ethylene acrylic elastomer

Blends prepared by melt mixing of thermoplastic elastomer have gained considerable attention in recent years from a heat shrinkability point of view. Our present study deals with the measurement of heat shrinkability of the maleic anhydride grafted low‐density polyethylene and ethylene acrylic elastomer. Two samples have been prepared to study the effect of coupling agent's reactivity on the shrinkability of the blends. The coupling agents used are 4,4′‐diamino diphenyl sulphone, and 4,4′‐diamino diphenyl methane. Shrinkability was measured at room temperature, 120 °C, 150 °C, and 180 °C. Shrinkability is found to be greater in high temperature stretched sample rather than that of room temperature stretched sample. It is observed that reactivity as well as heat shrinkability is more when 4,4′‐diamino diphenyl methane is used as a coupling agent. The mechanism of interchain crosslinking reaction has been confirmed by IR spectroscopy. Differential scanning calorimetry was performed to study the thermal stability of the sample. Copyright © 2002 John Wiley & Sons, Ltd.     

Stress–strain behavior of low‐density polyethylene/poly(methyl methacrylate) blends with modulated interfaces with a hydrogenated polybutadiene‐block‐poly(methyl methacrylate) diblock copolymer

The stress–strain diagrams and ultimate tensile properties of uncompatibilized and compatibilized hydrogenated polybutadiene‐block‐poly(methyl methacrylate) (HPB‐b‐PMMA) blends with 20 wt % poly(methyl methacrylate) (PMMA) droplets dispersed in a low‐density polyethylene (LDPE) matrix were studied. The HPB‐b‐PMMA pure diblock copolymer was prepared via controlled living anionic polymerization. Four copolymers, in terms of the molecular weights of the hydrogenated polybutadiene (HPB) and PMMA sequences (22,000–12,000, 63,300–31,700, 49,500–53,500, and 27,700–67,800), were used. We demonstrated with the stress–strain diagrams, in combination with scanning electron microscopy observations of deformed specimens, that the interfacial adhesion had a predominant role in determining the mechanism and extent of blend deformation. The debonding of PMMA particles from the LDPE matrix was clearly observed in the compatibilized blends in which the copolymer was not efficiently located at the interface. The best HPB‐b‐PMMA copolymer, resulting in the maximum improvement of the tensile properties of the compatibilized blend, had a PMMA sequence that was approximately half that of the HPB block. Because of the much higher interactions encountered in the PMMA phase in comparison with those in HPB (LDPE), a shorter sequence of PMMA (with respect to HPB but longer than the critical molecular weight for entanglement) was sufficient to favor a quantitative location of the copolymer at the LDPE/PMMA interface. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 22–34, 2005     

Shrinkability of ethylene vinyl acetate/polyurethane blends and their characterization

Heat shrinkability of the polymer, which depends on the elastic memory, is being utilized in various applications, mainly in the field of encapsulation. The elastic memory is introduced into the system in the form of an elastomeric phase. Here the blends of ethylene vinyl acetate and polyurethane were studied with reference to their shrinkability, introducing crosslinking in both the phases. It is found that with increase in elastomer content the shrinkage increased to a certain level and then decreased. With increase in cure time shrinkage is decreased. It is seen that high‐temperature (HT) stretched samples showed higher shrinkage than room temperature (RT) stretched one. Generally, the crystallinity of the HT stretched sample is higher than that of low‐temperature stretched sample, which is again higher than that of original sample. From high temperature differential scanning calorimetry it is found that with increase in PU content stability towards oxygen is increased and further high temperature processing decreases the initial degradation temperature but enhances the rate of degradation. From scanning electron microscopy it is seen that an HT stretched sample is more elongated than an RT stretched one. Copyright © 2000 John Wiley & Sons, Ltd.     

Ethylene/vinyl acetate copolymer/clay nanocomposites

This article highlights the history, synthetic routes, material properties, and scope of ethylene/vinyl acetate copolymer (EVA)/clay nanocomposites. These nanocomposites of EVAs are achieved with either unmodified or organomodified layered silicates with different methods. The structures of the resulting polymer/inorganic nanocomposites have been characterized with X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The addition of a small amount of clay, typically less than 8 wt %, to the polymer matrix unusually promotes the material properties, such as the mechanical, thermal, and swelling properties, and increases the flame retardancy of these hybrids. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 471–480, 2006     

Structure and properties of compatibilized recycled poly(ethylene terephthalate)/linear low density polyethylene blends

Blends of recycled poly(ethylene terephthalate) (R-PET) and linear low density polyethylene (LLDPE) were compatibilized with poly(styrene-ethylene/butyldiene-styrene) (SEBS) and maleic anhydride-grafted poly(styrene-ethylene/butyldiene-styrene) (SEBS-g-MA). Effects of compatilizer were evaluated systematically by study of mechanical, thermal and morphology properties together with crystallization behavior of PET. Tensile properties of the blends were improved effectively by the addition of 10 wt% SEBS-g-MA, elongation at break and charpy impact strength were increased with the increasing content of compatilizer. SEBS-g-MA is more effectual on mechanical properties of R-PET/LLDPE blends than SEBS. DSC analysis illustrates crystallinities of PET and LLDPE were increased by compatilizer at annealing condition. WAXD and FT-IR spectra show that annealing influences crystallization behavior of PET. Different compatilizer content results in different morphology structure, in particular, higher SEBS-g-MA content can induce the formation of a salami microstructure.     

Binary and ternary blends of high‐density polyethylene with poly(ethylene terephthalate) and polystyrene based on recycled materials

Binary blends of recycled high‐density polyethylene (R‐HDPE) with poly(ethylene terephthalate) (R‐PET) and recycled polystyrene (R‐PS), as well as the ternary blends, i.e. R‐HDPE/R‐PET/R‐PS, with varying amounts of the constituents were prepared by twin screw extruder. The mechanical, rheological, thermal, and scanning electron microscopy (SEM) analyses were utilized to characterize the samples. The results revealed that both R‐HDPE/R‐PET and R‐HDPE/R‐PS blends show phase inversion but at different compositions. The R‐PET was found to have much higher influence on the properties enhancement of the R‐HDPE compared to R‐PS, but at the phase inverted situation, a significant loss in the tensile strength of R‐HDPE/R‐PET blend was observed due to the weak interaction at this morphological state. However, the ternary blends with higher loading of second phase, namely greater than 50 wt% of R‐PET+R‐PS, demonstrated better mechanical properties than the binary blends with the same content of either R‐PET or R‐PS. Copyright © 2009 John Wiley & Sons, Ltd.     

Crystal and phase morphology of dynamic-packing-injection-molded high-density polyethylene/ethylene vinyl acetate blends

The effect of shear stress, provided by so-called dynamic-packing injection molding, on crystal morphology and phase behavior was investigated for high-density polyethylene (HDPE) in blends with ethylene vinyl acetate (EVA) of various viscosities and vinyl acetate (VA) contents, with the aid of differential scanning calorimetry, two-dimensional small-angle X-ray scattering (2D SAXS), and scanning electron microscopy (SEM). A shish-kebab pattern was found in the oriented zones of dynamic samples, and the ratio of shish to kebab increased as a function of the EVA content in the blends up to 20 wt %, regardless of the VA content. This showed that molecules of HDPE could easily be stretched to form a shish structure in the presence of EVA. Moreover, a large increase in the long spacing, characterized by 2D SAXS measurements, was achieved because of the presence of EVA. The SEM results showed an obvious decrease in the domain size of the EVA phase under the effect of shear stress. All these results suggested shear-induced mixing between HDPE and EVA, in that ethylene segments of EVA molecules could be forged in the shish structure during shear and the other fractions of EVA were located in the amorphous regions between the adjacent lamellae of HDPE. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1831–1840, 2004     

A comparative study of thermal ageing characteristics of poly(ethylene‐co‐vinyl acetate) and poly(ethylene‐co‐vinyl acetate)/carbon black mixture

In this comparative study, the effect of carbon black (CB) on the thermal ageing characteristics of poly(ethylene‐co‐vinyl acetate) (EVA) was investigated. EVA, containing 13% vinyl acetate (VA), and poly(ethylene‐co‐vinyl acetate)/carbon black mixture (EVA/CB) containing 13% VA and 1% CB were aged at 85°C in air up to 30 weeks. Sol‐gel analysis experiments were made to determine the percentage gelation of both virgin and aged samples. FT‐IR measurements were performed to follow the chemical changes which took place in the samples during ageing. Dynamic and isothermal thermogravimetric studies were performed for determination of the thermal stabilities of virgin and aged samples. Sol‐gel analysis results showed that EVA itself has a tendency to form a gel under thermal treatment, whereas EVA/CB never becomes a gel when being thermally aged under the same conditions. As a result of FT‐IR measurements, some oxidation products such as ketone, lactone and vinyl species were observed through thermal ageing of EVA. It is also clear that these kind of oxidation products did not appear to a considerable extent in EVA/CB. Thermal analysis experiments exhibit that thermal stability of EVA decreased through thermal ageing; whereas that of EVA/CB remained almost unchanged. Copyright © 2004 John Wiley & Sons, Ltd.