Process of grafting styrene onto LLDPE by swelling and suspension copolymerization

A technology of swelling and suspension copolymerization was conducted to graft styrene onto linear low‐density polyethylene (LLDPE). The graft mechanism of styrene with LLDPE had been described by ¹H NMR and IR. The mean particle diameter and size distribution of the products with different proportions of LLDPE to styrene monomer were calculated. The morphology and thermal behavior of copolymers were characterized by scanning electron microscopy and differential scanning calorimetry. The glass transition temperature of copolymers increased with the addition of LLDPE, which proved the existence of the polyethylene‐g‐polystyrene copolymer. The grafting efficiency and granulation rate of suspension copolymerization were investigated. It was found that the grafting efficiency increased and the granulation rate decreased with the addition of LLDPE. POLYM. ENG. SCI., 50:1713–1720, 2010. © 2010 Society of Plastics Engineers     

Compatibilization effect of graft copolymer on immiscible polymer blends. II. LLDPE/PS/LLDPE-g-PS systems

The compatibilizing effect of graft copolymer, linear low density polyethylene-g-polystyrene (LLDPE-g-PS), on immiscible LLDPE/PS blends has been studied by means of ¹³C CPMAS NMR and DSC techniques. The results indicate that LLDPE-g-PS is an effective compatibilizer for LLDPE/PS blends, and the compatibilizing effect of LLDPE-g-PS on LLDPE/PS blends depends on the PS grafting yield and molecular structure of the compatibilizers and also on the composition of the blends. It was found that LLDPE-g-PS chains connect two immiscible components, LLDPE and PS, through solubilization of chemically identical segments of LLDPE-g-PS into the noncrystalline region of the LLDPE and PS domain, respectively. Mean while, LLDPE-g-PS chains connect the crystalline region of LLDPE by isomorphism, resulting in an obvious change in the crystallization behavior of LLDPE. © 1996 John Wiley & Sons, Inc.     

ABS modified with hydrogenated polystyrene‐grafted‐natural rubber

Natural rubber (NR) latex was grafted by emulsion polymerization with styrene monomer, using cumene hydroperoxide/tetraethylene pentamene as redox initiator system. The polystyrene‐grafted NR (PS‐g‐NR) was hydrogenated by diimide reduction in the latex form using hydrazine and hydrogen peroxide with boric acid as a promoter. At the optimum condition for graft copolymerization, a grafting efficiency of 81.5% was obtained. In addition, the highest hydrogenation level of 47.2% was achieved using a hydrazine:hydrogen peroxide molar ratio of 1:1.1. Hydrogenation of the PS‐g‐NR (H(PS‐g‐NR)) increased the thermal stability. Transmission electron microscopy analysis of the H(PS‐g‐NR) particles revealed a nonhydrogenated rubber core and hydrogenated outer rubber layer, in accordance with the layer model. The addition of H(PS‐g‐NR) at 10 wt % as modifier in an acrylonitrile–butadiene–styrene (ABS) copolymer increased the tensile and impact strengths and the thermal resistance of the ABS blends, and to a greater extent than that provided by blending with NR or PS‐g‐NR. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Linear low‐density polyethylene/(soya powder) blends containing polyethylene‐g‐(maleic anhydride) as a compatibilizer

Blends were made from linear low‐density polyethylene (LLDPE) and various amounts of soya powder. The soya powder content was varied from 5 to 20 wt%. Polyethylene‐g‐(maleic anhydride) (PE‐g‐MA) was used as a compatibilizer. Tensile strength and elongation at break (EB) decreased with increasing soya powder content. However, Young's modulus increased with the incorporation of soya powder. The addition of PE‐g‐MA as a compatibilizer increased the tensile strength, EB, and modulus of the blends. The interfacial adhesion between soya powder and LLDPE was improved by the incorporation of PE‐g‐MA, as demonstrated by scanning electron microscopy. Increasing the content of soya powder reduced the crystallinity of the LLDPE phase. The addition of PE‐g‐MA had no significant effect on melting temperature, but the degree of crystallinity of the LLDPE was increased. The thermal stability of the blends was determined by using thermogravimetric analysis. Thermal stability decreased with increasing soya powder loading. However, the addition of PE‐g‐MA slightly increased the thermal stability of LLDPE/(soya powder) blends. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

A facile,green, versatile protocol to prepare polypropylene‐g‐poly(methyl methacrylate) copolymer by water‐solid phase suspension grafting polymerization using the surface of reactor granule technology polypropylene granules as reaction loci

A facile and environment friendly process, called water‐solid phase suspension grafting polymerization, was developed to prepare polypropylene‐g‐poly(methyl methacrylate) (PP‐g‐PMMA) copolymer with a submicrometer microdomain. In this approach, graft polymerization was elaborately regulated to occur within micropores of polypropylene particles prepared by reactor granule technology. FTIR spectra of the samples after extraction demonstrated that PMMA was successfully grafted onto the PP. The results showed grafting percentage (GP) of PMMA increased with the increasing monomer ratios to PP and that could reach 13.6%. Whereas the grafting efficiency decreased as the monomer ratio increased. The addition of second monomer styrene improved GP up to 24.5%. Differential Scanning Calorimetry tests showed that the grafting of PMMA have a slight effect on the melting point and the relative crystallinity of PP. TEM micrographs demonstrated PMMA domains distributed in PP matrix with sizes ranging from about 100 to 300 nm. In addition, Shear viscosity increased with the growing GP indicated by rheological measurement. The preliminary evaluation showed PP‐g‐PMMA was effective in improving the compatibility of PP/acrylonitrile‐styrene‐acrylate blends. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Study of multi‐monomer melt‐grafting onto polypropylene in an extruder

Free‐radical melt‐grafting of the dual‐monomer systems glycidyl methacrylate–styrene (GMA‐St) and hydroxyethyl methacrylate–styrene (HEMA‐St) onto polypropylene (PP) has been studied using a single‐screw extruder. For single monomer grafting systems, degradation of PP was unavoidable and deterioration of the mechanical properties of the grafted PP subsequently occurred because of β‐scission of PP chains during the free‐radical melt‐grafting process. However, for the dual‐monomer systems, it is shown that the addition of styrene as a comonomer can significantly enhance the GMA or HEMA grafting levels on PP and reduce the extent of β‐scission of PP backbone. It has been found that the grafting degree of dual‐monomer melt‐grafted PP, such as PP‐g‐(GMA‐co‐St) or PP‐g‐(HEMA‐co‐St), is about quadruple that of single‐monomer grafted PP for the same monomer and dicumyl peroxide concentrations. Moreover, the melt flow rate of the dual‐monomer grafted PP is smaller than that of the unmodified PP. Hence, PP not only was endowed with higher polarity, but also kept its good mechanical properties. © 2000 Society of Chemical Industry     

Synthesis and characterization of graft copolymers of syndiotactic polystyrene with polybutadiene and 4‐methylstyrene

The basic method for synthesizing syndiotactic polystyrene‐g‐polybutadiene graft copolymers was investigated. First, the syndiotactic polystyrene copolymer, poly(styrene‐co‐4‐methylstyrene), was prepared by the copolymerization of styrene and 4‐methylstyrene monomer with a trichloro(pentamethyl cyclopentadienyl) titanium(IV)/modified methylaluminoxane system as a metallocene catalyst at 50°C. Then, the polymerization proceeded in an argon atmosphere at the ambient pressure, and after purification by extraction, the copolymer structure was confirmed with ¹H‐NMR. Lastly, the copolymer was grafted with polybutadiene (a ready‐made commercialized unsaturated elastomer) by anionic grafting reactions with a metallation reagent. In this step, poly(styrene‐co‐4‐methylstyrene) was deprotonated at the methyl group of 4‐methylstyrene by butyl lithium and further reacted with polybutadiene to graft polybutadiene onto the deprotonated methyl of the poly(styrene‐co‐4‐methylstyrene) backbone. After purification of the graft copolymer by Soxhlet extraction, the grafting reaction copolymer structure was confirmed with ¹H‐NMR. These graft copolymers showed high melting temperatures (240–250°C) and were different from normal anionic styrene–butadiene copolymers because of the presence of crystalline syndiotactic polystyrene segments. Usually, highly syndiotactic polystyrene has a glass‐transition temperature of 100°C and behaves like a glassy polymer (possessing brittle mechanical properties) at room temperature. Thus, the graft copolymer can be used as a compatibilizer in syndiotactic polystyrene blends to modify the mechanical properties to compensate for the glassy properties of pure syndiotactic polystyrene at room temperature. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Thermal properties and morphology of noncrosslinking linear low‐density polyethylene‐grafted acrylic acid

Noncrosslinking linear low‐density polyethylene‐grafted acrylic acid (LLDPE‐g‐AA) was prepared by melt‐reactive extrusion in our laboratory. The thermal behavior of LLDPE‐g‐AA was investigated by using differential scanning calorimetry (DSC). Compared with neat linear low‐density polyethylene (LLDPE), melting temperature (T_m) of LLDPE‐g‐AA increased a little, the crystallization temperature (T_c) increased about 4°C, and the melting enthalpy (ΔH_m) decreased with an increase in acrylic acid content. Isothermal crystallization kinetics of LLDPE and LLDPE‐g‐AA samples were carried out by using DSC. The overall crystallization rate of LLDPE was smaller than that of grafted samples. It showed that the grafted acrylic acid monomer onto LLDPE acted as a nucleating agent. Crystal morphologies of LLDPE‐g‐AA and LLDPE were examined by using SEM. Spherulite sizes of LLDPE‐g‐AA samples were lower than that of LLDPE. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2626–2630, 2002     

Effect of reaction conditions on grafting ratio and properties of starch nanocrystals‐g‐polystyrene

Starch nanocrystals‐g‐polystyrene (StN‐g‐PS) was synthesized by free radical emulsion copolymerization of starch nanocrystals with styrene. The effect of polymerization conditions on grafting efficiency (GE) and grafting ratio (GR) were investigated. It was found that during graft copolymerization procedure both GE and GR increase with increasing monomer concentration and reaction time. As a result the high GE and high GR can be achieved. The good linear fit of the GR with A_St/A_OH (the absorption strength ratio of aromatic ring peaks and hydroxyl group peaks) confirmed that during graft copolymerization, FTIR spectra can be used as a simple method for determining GR. X‐ray diffraction showed that the crystallinity of StN‐g‐PS decreased slightly with increasing GR. Grafted polystyrene side chains can improve the interface compatibility of starch nanocrystals with the hydrophobic polymer matrix. The mechanical properties of StN‐g‐PS/rubber nanocomposites can be obviously enhanced. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40571.     

Effects of the molecular structure of impact modifier and compatibilizer on the toughening of PBT/SBS/PS‐GMA blends

This work aims at studying the toughening process of poly(butylene terephthalate) (PBT) through its blends with styrene‐butadiene‐styrene block copolymers (SBS), in the presence of poly(styrene‐ran‐glicydil methacrylate) (PS‐GMA) as reactive compatibilizer. High values of impact strength were attained for PBT/SBS blends without the compatibilizer; however, this improvement is achieved for blends with SBS having similar viscosity compared to PBT, at high SBS content (40 wt %) and for blends prepared under specific processing conditions. The efficiency of the in situ compatibilization of PBT/SBS blends by PS‐GMA was found to be strongly dependent on the SBS and PS‐GMA molecular characteristics. Better compatibilizing results were observed through fine phase morphologies and lower ductile to brittle transition temperatures (DBTT) as the interfacial interaction and stability of the in situ formed compatibilizer are maximized, that is, when the miscibility between SBS and PS‐GMA and reaction degree between PBT and PS‐GMA are maximized. For the PBT/SBS/PS‐GMA blends under study, this was found when it is used the SBS with higher polystyrene content (38 wt %) and with longer PS blocks (M_w = 20,000 g mol^?1) and also the PS‐GMA with moderate GMA contents (4 wt %) and with molecular weight similar to the critical one for PS entanglements (M_c = 35,000 g mol^?1). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5795–5807, 2006     

Graft copolymerization of oleic acid onto low‐density polyethylene in the molten state

A graft copolymer of oleic acid (OA) onto low‐density polyethylene (LDPE) was prepared using dicumyl peroxide (DCP) as an initiator in the molten state. The grafting was carried out in a Haake rheometer. The effects of the reaction time and the amount of DCP and the monomer on the percentage of grafting were studied. The rheological behavior and the melt‐flow rate of the graft copolymer (LDPE‐g‐OA) were also investigated. FTIR spectroscopy and a mass spectrum were used to characterize the structure of LDPE‐g‐OA. The experimental results showed that when the OA amount was 10 wt % and the DCP amount was 0.4 wt % based on the LDPE the percentage of grafting of LDPE‐g‐OA, prepared by maintaining the temperature at 170°C and the roller speed at 80 rpm, was about 6 wt %. It was found that both LDPE and LDPE‐g‐OA were pseudoplastic fluids. OA was grafted onto LDPE in the form of a monomer and a dimer. The grafted LDPE is expected to act as a compatibilizer between starch and polyethylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3299–3304, 2003     

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     

Modification of polypropylene via the free‐radical grafting ternary monomer in water suspension systems

Maleic anhydride, styrene, and butyl acrylate were grafted onto polypropylene (PP) via free‐radical polymerization. The grafted product, polypropylene‐g‐(maleic anhydride–styrene–butyl acrylate) (PP‐g‐PMSB), was prepared in a water suspension system, and a nongrafted polymer, poly(maleic anhydride–styrene–butyl acrylate) (PMSB′), was produced at the same time. The optimal synthesis conditions were determined by orthogonal experiments. The crystallinity, thermal stability, melt flow rate, and hydrophilicity of the grafting samples were investigated in the presence or absence of PMSB′. The results indicate that the grafting percentage (G_p) of PP‐g‐PMSB and the content of PMSB′ (C_m) increased as the monomer content increased under the optimum reaction conditions. All of these ternary monomers were grafted onto the PP backbone as long‐chain branches. With increasing G_p, PP‐g‐PMSB's polarity and thermal stability increased, the crystallinity decreased, and the molecular distribution became narrower. The contact angle decreased to 72.12° when G_p was 6.87%. With increasing C_m, the crystallinity and thermal stability of the grafting products decreased compared to PP‐g‐PMSB and the molecular distribution grew wider. The contact angle decreased to 63.51° when C_m was 3.64%; this indicated that the presence of PMSB′ further improved the hydrophilicity of the grafted products. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Cross‐linking and grafting with PS of EPDM in the presence of Lewis acids

With Lewis Acids as catalysts in melt system, the influence of kinds of Lewis Acids, dosages of catalysts on the behaviors of crosslinking and grafting of ethylene–propylene–diene rubber (EPDM) were investigated. The Lewis Acids, such as anhydrous AlCl₃, FeCl₃, SnCl₄, could initiate the crosslinking of EPDM and the grafting between EPDM and polystyrene (PS). The carbon–carbon double bonds existing on EPDM chain were favorable to the formation of the initial carbocation in the presence of Lewis Acids. The carbocation initiated carbonium ion polymerization between the unsaturated bonds, or substituted for a proton from the phenyl in the presence of PS forming EPDM‐g‐PS copolymer. Anhydrous aluminum chloride was found to be an efficient catalyst and its initiating temperatures for crosslinking or grafting were about 110°C. The amounts of gel and the data of torques showed that there was a competition between the crosslinking‐grafting reaction and the degradation of blending components in the presence of AlCl₃. The EPDM‐g‐PS copolymer served as a compatibilizer in the EPDM/PS blends and enhanced the mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and application of MDPE‐g‐GMA as reactive compatibilizer in blends of MDPE/PET and MDPE/PA6

In the present study, glycidyl methacrylate (GMA) grafted medium density polyethylene (MDPE‐g‐GMA) was synthesized in the molten state and applied as a reactive compatibilizer in MDPE/polyamid6 (PA6) and in MDPE/poly(ethylene terephtalate) (PET) blends. Graft copolymerization of GMA onto MDPE was performed in presence and absence of styrene, with different concentrations of dicumyl peroxide (DCP) as a radical initiator. In the presence of styrene, the MDPE‐g‐GMA with 6% GMA was obtained by addition of only 0.1 phr of DCP. Furthermore, the maximum grafting was reached when 0.6 and 0.7 phr concentration of DCP for styrene containing and styrene free samples were used, respectively. Torque‐time measurement showed faster grafting reaction rate in the presence of styrene. Four MDPE‐g‐GMA samples were selected as compatibilizers in the blends. Furthermore, the effects of melt flow index and grafting content of compatibilizers on mechanical properties and morphology of the blends were investigated through tensile tests and SEM analysis. Tensile test results indicated that the presence of compatibilizers in the blends led to 250 and 133% increase in elongation at break for PA6 and PET blends, respectively. Moreover, the best tensile results for blends were obtained using MDPE‐g‐GMA with high flow ability. The average particle size of the dispersed phase decreased by 350% for PA6 and 300% for PET blends compared with nonreactive blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of different compatibilizers on the rheological,thermomechanical, and morphological properties of HDPE/LLDPE blend‐based nanocomposites

The influence of two different compatibilizers and their combination (maleic anhydride grafted high density polyethylene, HDPE‐g‐MA; maleic anhydride grafted linear low density polyethylene, LLDPE‐g‐MA; and 50/50 wt % mixture of these compatibilizers) on the rheological, thermomechanical, and morphological properties of HDPE/LLDPE/organoclay blend‐based nanocomposites was evaluated. Nanocomposites were obtained by melt‐intercalation in a torque rheometer in two steps. Masterbatches (compatibilizer/nanoclay 2:1) were obtained and subsequently diluted in the HDPE/LLDPE matrix producing nanocomposites with 2.5 wt % of nanoclay. Wide angle X‐ray diffraction (WAXD), steady‐state rheological properties, and transmission electron microscopy (TEM) were used to determine the influence of different compatibilizer systems on intercalation and/or exfoliation process which occurs preferentially in the amorphous phase, and thermomechanical properties. The LLDPE‐g‐MA with a high melt index (and consequently low viscosity and crystallinity) was an effective compatibilizer for this system. Furthermore, the compatibilized nanocomposites with LLDPE‐g‐MA or mixture of HDPE‐g‐MA and LLDPE‐g‐MA exhibited better nanoclay's dispersion and distribution with stronger interactions between the matrix and the nanoclay. These results indicated that the addition of maleic anhydride grafted polyethylene facilitates both, the exfoliation and/or intercalation of the clays and its adhesion to HDPE/LLDPE blend. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1726–1735, 2013     

Influence of core–shell rubber particles synthesized with different initiation systems on the impact toughness of modified polystyrene

Core–shell poly(butadiene‐graft‐styrene) (PB‐g‐PS) rubber particles were synthesized with different initiation systems by emulsion grafting polymerization. These initiation systems included the redox initiators and an oil‐soluble initiator, 1,2‐azobisisobutyronitrile (AIBN). Then the PB‐g‐PS impact modifiers were blended with polystyrene (PS) to prepare the PS/PB‐g‐PS blends. In the condition of the same tensile yield strength on both samples, the Izod test showed that the notched impact strength of PS/PB‐g‐PS(AIBN) was 237.8 J/m, almost 7 times than that of the PS/PB‐g‐PS(redox) blend, 37.2 J/m. From transmission electron microscope (TEM) photographs, using the redox initiators, some microphase PS zones existed in the core of PB rubber particles, which is called “internal‐grafting.” This grafting way was inefficient on toughening. However, using AIBN as initiator, a great scale of PS subinclusion was seen within the PB particle core, and this microstructure increased the effective volume fraction of the rubber phase with a result of improving the toughness of modified polystyrene. The dynamic mechanical analysis (DMA) on both samples showed that the glass transition temperature (T_g) of rubber phase of PS/PB‐g‐PS(AIBN) was lower than that of PS/PB‐g‐PS(redox). As a result, the PB‐g‐PS(AIBN) had better toughening efficiency on modified polystyrene than the PB‐g‐PS(redox), which accorded with the Kerner approximate equation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 738–744, 2007     

Graft copolymerization of methyl acrylate onto chitosan initiated by potassium diperiodatoargentate (III)

A novel efficient redox system—potassium diperiodatoargentate [Ag(III)]‐chitosan—was employed to initiate the graft copolymerization of methyl acrylate (MA) onto chitosan in aqueous alkali solution. The effects of reaction variables such as monomer concentration, initiator concentration, reaction time, and temperature were investigated and the grafting conditions were optimized. The structures and the thermal stability of chitosan and chitosan‐g‐PMA were characterized by infrared spectroscopy (IR) and thermogravimetric analysis (TGA). The solubility of chitosan‐g‐PMA in some mixed solvent was tested. The graft copolymer was shown to be an effective compatibilizer in blends of poly(vinyl chloride) (PVC) and chitosan. Finally, a mechanism is proposed to explain the formation of radicals and the initiation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 799–804, 2006     

Melt grafting of maleic anhydride onto polypropylene with 1‐decene as a second monomer

The influence of 1‐decene as the second monomer on the melt‐grafting behavior of maleic anhydride (MAH) onto polypropylene (PP) was studied with differential scanning calorimetry and Fourier transform infrared spectroscopy. We found that the value of the grafting degree increased from 0.68% for pure MAH‐g‐PP to 1.43% for the system with a 1‐decene/MAH molar ratio of 0.3, whereas the maximum value with styrene (St) as the second monomer was 0.98% under an St/MAH molar ratio of 1.0. Compared with the contribution of St/MAH‐g‐PP to the peeling strength between the PP and polyamide (PA) layer for a PP/PA laminated film, the introduction of 1‐decene/MAH‐g‐PP increased the peeling strength from 180 g/15 mm to 250 g/15 mm. 1‐Decene inhibited the chain scission behavior of PP. 1‐Decene reacted with MAH to form a 1‐decene/MAH copolymer or the Alder‐ene reaction product before the two monomers grafted onto PP. The grafting of the reactive product onto PP greatly improved the grafting degree of MAH. What is more, because of the similar chemical structures of 1‐decene and PP, the affinity of 1‐decene with PP was higher than that of St. Compared with St, the introduction of less 1‐decene led to a higher grafting degree and higher peeling strength. Therefore, we concluded that 1‐decene was more effective for improving the grafting degree of MAH onto PP. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Mechanical properties and morphology of polylactide,linear low‐density polyethylene,and their blends

Melt blending of linear low density polyethylene (LLDPE) and polylactide (PLA) was performed in an extrusion mixer with post extrusion blown film attachment with and without compatibilizer‐grafted low density polyethylene maleic anhydride. The blend compositions were optimized for tensile properties as per ASTM D 882‐91. On the basis of this, LLDPE 80 [80 wt % LLDPE and 20 wt % poly(L ‐lactic acid) (PLLA)] and MA‐g‐low‐density polyethylene 80/4 (80 wt % LLDPE, 20 wt % PLLA, and 4 phr compatibilizer) were found to be an optimum composition. The blends were characterized according to their mechanical, thermal, and morphological behavior. Fourier transform infrared spectroscopy revealed that the presence of compatibilizer enhanced the blend compatibility to some extent. The morphological characteristics of the blends with and without compatibilizer were examined by scanning electron microscopy. The dispersion of PLLA in the LLDPE matrix increased with the addition of compatibilizer. This blend may be used for packaging applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010