Compatibilizer Agent Research Articles

The Effects of High Energy Radiation on the Tensile Properties of Rubber Toughened Nanocomposites

Composites based on high density polyethylene (HDPE), ethylene propylene diene monomer (EPDM) and Organically Modified Montmorillonite (OMMT) clays were made by melt compounding followed by compression molding. Mechanical properties, X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) were used to characterize the nanocomposites. The addition of clay, compatibilizer agent, Maleic Anhydride Polyethylene (MAPE) and irradiation technique, High Energy Electron Beam (EB) considerably improved the properties of nanocomposites. Tensile Strength and Modulus (MPa) were found to increase significantly with increasing clay content and decreasing as the clay content exceeds 4 vol%. The largest improvement in nanocomposite tensile properties occurred at clay loading of 4 vol% (2-8 vol%) with irradiation technique. The d spacings of the clay in nanocomposites were monitored using XRD and the extent of delamination was examined by TEM. TEM photomicrographs illustrated the intercalated and exfoliated structures of the nanocomposites with OMMT, MAPE and irradiation process.

Study and characterization of composites materials based on polypropylene loaded with olive husk flour

AbstractIn Algeria, a significant quantities of olive husk are rejected to nature causing by the way major nuisances to environment, to give us a reason for which our work is focused on the valorization of this waste by its incorporation in a polypropylene matrix. The hydrophilic nature of natural fibers affects negatively its adhesion to hydrophobic polymeric matrix. To improve interfacial adhesion, two modes of chemical treatments were done using vinyltriacetoxysilane (VTAS) and maleic‐anhydride‐polypropylene (PPMA) compatibilisant agent. Several formulations of PP filled with 10 and 20% by mass of olive husk flour treated (OHFT) and untreated (OHFUT) were prepared. The chemical modification of olive husk flour was studied by Fourier transform infrared (FTIR) spectroscopy. The tensile properties, the water‐absorption behavior, the thermal degradation properties, and crystallinity of the composites were investigated. It was found that, the incorporation of the treated and untreated OHF improves the thermal stability of the composites. However, the use of the compatibilizer agent PPMA leads to a better thermal stability compared with the treatment of the OHF by the VTAS and the OHFUT. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Use of EPDMSDD as compatibilizer agent for EPDM/EPDMR blends: Rheologic, mechanical, and morphologic properties

AbstractAround the world, concern is growing about the amount of waste rubber going into landfills. Policymakers are encouraging researchers to find innovative ways to recycle this waste. In this study, as part of an effort to recycle waste rubber (EPDMR) as filler in compositions of EPDM, we prepare a terpolymer of ethylene–propylene–diene with 1‐dodecanethiol (EPDMSDD). We use it as a compatibilizing agent to improve adhesion and incorporation of the residue (EPDMR) in EPDM/EPDMR blends. We synthesize and characterize EPDMSDD through 13C‐NMR and FTIR spectroscopy. We evaluate the effect of the compatibilizer EPDMSDD using vulcanization parameters, such as optimum cure time, scorch time, and torque. To evaluate its effect on the interaction between EPDMSDD/EPDMR, we carried out mechanical tests of samples with and without EPDMSDD. Our findings show that the tensile strength and elongation increased with the addition of EPDMSDD, indicating a better interaction between EPDMR/EPDM. Tear strength also increased with the presence of EPDMSDD, particularly for the amount of 70 and 80 phr of EPDMR. This suggests a good adhesion between the phases in high amounts of waste. The micrographs of the mixtures revealed that the addition of EPDMSDD improved the dispersion of the EPDMR in the EPDM phase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.

Improvement in mechanical properties of reinforced thermoplastic elastomer composite with kenaf bast fibre

This paper report on the development of thermoplastic elastomer composite reinforced with 20 vol.% kenaf fibre. Two types of impact modifier were blended with polypropylene (PP) namely; thermoplastic natural rubber (TPNR) and polypropylene/ethylene–propylene–diene–monomer (PP/EPDM). Both composites were produced via double melt blending method using Haake internal mixer before they were compression moulded. The ratio of thermoplastic:elastomer was 70:30 for both polymer blends. Due to incompatibility between matrix and reinforcement, maleic anhydride polypropylene (MAPP) was added as in the case of treated composite. It was found that the tensile strength for TPNR is about 12% higher than the PP/EPDM matrix. The present of kenaf fibre (KF) and MAPP however has significantly increased the tensile strength of the PP/EPDM composite by approximately 81% while only 55% increment attained in TPNR–KF–MAPP as compared to unreinforced TPNR. Apart from that, flexural properties and impact strength are greatly improved for treated kenaf fibre composite. This shows that KF has imparted its tensile strength to the PP/EPDM system with good interaction provided by the compatibilizer agent. Scanning electron micrographs (SEMs) revealed that the improvement achieved in mechanical properties was due to the interaction between both matrix systems and kenaf fibre.

POLYPROPYLENE/CLAY NANOCOMPOSITES: SYNTHESIS AND CHARACTERIZATION

abstract Polypropylene nanocomposites were synthesized by using the method of mixing in the molten state. Nanocomposites were obtained in twin-screw co-rotating extruders and the nanocomposites were prepared with percentage of nanoclay (C 2 ) from 5 wt-%, with and without compatibilizer agent (PP- g -MA).The thermal (DSC, TGA), morphology (XRD, TEM), and dynamical mechanical (DMA) properties of the nanocomposites were characterized.All nanocomposites prepared are in intercalated state as corroborated by XRD and TEM. The Tm and Xc were not affected by the presence of clay, PP-g-MA, or processing support. The incorporation of clay and compatibilizer agent increases the thermal stability and heat deflection temperature (HDT). Keywords : Nanocomposites, polypropylene, clays. compatiblizer agent 1. introdUction Polypropylene is a polymer widely used in many applications, and their thermal (1-2), rheological (3), mechanical (4-5), and gas permeation properties (6-7) need to be improved. A large number of studies have focused to improve a range of capabilities for these materials used in the automotive industries, and which show a great potential for use in the aeronautical field (7). The study of polymer nanocomposites has focused on enhancing the conventional properties of this polymeric material (8),

A Linear Relationship between the Mechanical, Thermal and Gas Barrier Properties of MAPE Modified Rubber Toughened Nanocomposites

Composites based on high density polyethylene (HDPE), ethylene propylene diene monomer (EPDM) and organophilic montmorillonite (OMMT) clays were prepared by melt compounding followed by compression molding. The addition of clay as well as compatibilizer agent (maleic anhydride polyethylene (MAPE)) considerably improved the tensile properties of nanocomposites systems. The largest improvement in mechanical and thermal properties occurred at clay loading levels of 4% (2-8 wt %) with MAPE system. Interestingly, the increased in tensile properties also resulted in improve in thermal and barrier properties. Differential scanning calorimeter analysis (DSC) revealed that the barrier property of nanocomposite was influenced by the crystalline percentage of nanocomposite. Along with crystalline percentage, the crystallization temperature, Tc and melting temperature, Tm were also improved with OMMT and MAPE agent. The d-spacings of the clay in nanocomposites were monitored using x-ray diffraction (XRD) and the extent of delamination was examined by transmission electron microscope (TEM). The wide angle of XRD patterns showed the increased interplanar spacing, d of clay layers, indicating enhanced compatibility between polymer matrix and OMMT with the aid of MAPE agent. TEM photomicrographs illustrated the mixed intercalated and partial exfoliated structures of the nanocomposites with OMMT and MAPE agent.

Melt Production and Antimicrobial Efficiency of Low-Density Polyethylene (LDPE)-Silver Nanocomposite Film

Colloidal silver nanoparticles with a size of 5.5 ± 1.1 nm were prepared by chemical reduction using polyethylene glycol (PEG). Silver nanoparticles were incorporated into low-density polyethylene (LDPE) by melt blending and subsequent hot pressing at 140 °C to produce nanocomposite film with an average thickness of 0.7 mm. PEG was added at 5% weight of polymer as a compatibilizer agent in order to prevent agglomeration and provide uniform distribution of nanoparticles in polymer matrix. Antimicrobial activity of silver nanocomposites against Escherichia coli ATCC 13706, Staphylococcus aureus ATCC12600, and Candida albicans ATCC10231 was evaluated by semi-qualitative agar diffusion test and quantitative dynamic shake flask test. Mechanical properties of nanocomposites were not significantly different from silver-free LDPE-containing PEG films (p > 0.05), and silver nanoparticles did not form chemical bonding with the polymer. LDPE-silver nanocomposite samples by more than 6.69 ppm silver nanoparticles showed considerable antimicrobial clear zone. LDPE-silver nanocomposite affected growth kinetic parameters of the examined bacteria and is more efficient on S. aureus than E. coli. Polyethylene-silver nanocomposites containing 22.64 ppm silver nanoparticles could reduce 57.8% growth rate and 23.3% maximum bacterial concentration and increase 35.8% lag time of S. aureus. This study shows the potential use of LDPE-silver nanocomposite as antimicrobial active film. Antimicrobial efficiency of silver nanocomposite depends on silver nanoparticles concentration; however, high level of silver nanoparticles may lead to weakening of mechanical properties.

Elemental Analysis of a Heterogeneous Polymeric System by EDS: Detection of the Compatibilizer Agent Containing Si Atoms and Silver Nano-Particles (AgNP´s) in High Impact Polystyrene

High impact polystyrene (HIPS) is considered a heterogeneous polymeric system and is constituted by a disperse phase of rubber particles within a continuous phase formed by a polystyrene (PS) matrix. During the synthesis of HIPS, PS is formed whereas some PS chains become chemically bonded to polybutadiene (PB) chains, resulting in a PB-g-PS copolymer, which decreases the interfacial tension between both incompatible phases, acting as a compatibilizer. In this study, 2 HIPS systems were evaluated by energy dispersive spectroscopy (EDS). In the first case, a HIPS composite was analyzed by EDS to locate the graft copolymer species containing Si atoms, which were previously synthesized by anionic polymerization using chloro-silane chemistry. The graft copolymer was incorporated to the HIPS synthesis from the beginning of the reaction in order to provide an improvement on the rubber phase stability. The graft copolymer was located at the interphase between the PS occlusions and the PB subdomains of the rubber particles. In the second case, HIPS was synthesized incorporating silver nanoparticles (AgNP´s) during the polymerization reaction, where the system can exhibit different types of morphology of the elastomeric phase (micelles, lamellas and core-shell). These structures overlapped the AgNP´s in the transmission electron microscopy (TEM) images, thus resulting this technique to be inadequate to establish the location of the AgNP´s. In this context EDS was used to evaluate the location and distribution of the AgNP´s by means of the elemental composition analysis. AgNP´s were preferentially detected in the PS phase as bigger clusters.

Improved dispersion of multi-wall carbon nanotubes in poly(butylene terephthalate) using benzimidazolium surfactants

AbstractMulti-wall carbon nanotubes/poly(butylene terephthalate) nanocomposites have been prepared by in-situ polymerization. Benzimidazolium tetrafluoroborate salts improve the dispersion of carbon nanotubes in the polymer matrix due to the formation of “π-cation” interactions of the imidazolium salt with the surface of the carbon nanotubes. An improved dispersion of the nanotubes in butanediol was also observed using the benzimidazolium salt. The presence of the compatibilization agent gives rise to improved thermo-mechanical properties and electrical conductivity for the nanocomposite. The presence of the nanotubes also consistently increases the thermal stability and enhances the nucleation process on PBT crystallization.

Utilization of Recycled Polypropylene for Production of Eco-Composites

Renewable raw materials and recyclable thermoplastic polymers provide attractive eco-friendly quality as well as environmental sustainability to the resulting natural fiber reinforced composites. We studied the possibility of using the recycled polypropylene (PP) for production of composites based on kenaf fibers (KF) and rice hulls (RH) as reinforcements. Polypropylene/rice-hulls (PP/RH/CA) and polypropylene/kenaf (PP/K/CA) composites with 30% fiber (filler) content and appropriate compatibilizing agent (CA)—a maleic anhydride grafted PP (MAPP), have been prepared by two steps procedure: melt mixing and compression molding. Flexural strength and thermal stability of the composites with recycled PP were similar to those with neat PP. The composites reinforced with kenaf fibers have shown better properties than those based on rice hulls. The flexural strength of the composite sample with recycled PP is 51.3 MPa in comparison with 51.1 MPa for the composite with neat PP. Degradation temperatures of neat and composite with recycled PP at residual weight 90% are 344.4°C and 343.5°C, respectively. The results obtained report the possibility of utilization of recycled PP for the production of natural reinforcements based composites with good mechanical characteristics for using as construction building materials in housing systems.

SBS nanocomposites as toughening agent for polypropylene

The toughening of polypropylene [PP] with styrene–butadiene–styrene rubber [SBS]/montmorillonite [MMT] nanocomposites was investigated with respect to morphological, thermal, and mechanical properties. The MMT/SBS nanocomposites were prepared in an internal mixer, using an epoxidized SBS [SBSe] to investigate its effect as a compatibilizer. The MMT/SBS nanocomposite was added to PP up to 10 wt%, aiming at material toughening. Transmission electron microscopy (TEM) revealed MMT induced dispersed-phase reductions when compared to typical PP/SBS blends. In addition, changes in the PP crystallization process were observed in the presence of the nanocomposite. Surprisingly, the use of nanofiller, combined with SBSe compatibilizer agent, increased the PP impact strength by about 60%, with no reduction in the tensile module.

Cellular Structure of Halogen-Free Flame Retardant Foams Based on LDPE

Composites of LDPE/ATH (up to 70 wt.%) were foamed to create new materials with good fire retardancy properties and low weight, proving the feasibility of developing cellular structures when high levels of inorganic fillers are included. An experimental study was carried out to explore the effects of chemical composition on cellular structure as well as the effect of structure on their thermal, mechanical and combustion properties. Samples fabrication was carried out using an improved compression moulding route consisting of polymer compounding, precursor preparation and foaming under pressure. The polymer matrix consisted of low density polyethylene as well as certain amount of LLDPE-g-MAH as compatibilizer agent. The inorganic filler used was aluminium trihydroxide (ATH) ranging from 0 wt.% to 70 wt.%. Furthermore, azodicarbonamide (ADC) was used as chemical blowing agent. Foamed samples with cell sizes below 100 microns were produced. These samples showed similar fire retardancy than their solid precursors. The compatibilization was proved indispensable to achieve a good adhesion between mineral filler and polymer and to improve the cellular structure. The increase of the amount of filler has an interesting effect on the cellular structure, going from a closed-cell (at low contents) to an open-cell (at higher contents) cellular structure. As a result of this investigation, halogen-free flame retardant cellular materials were processed, leading to a notable reduction of material compared to the solid one and to new properties which can result in new applications.

Effects of Mixing Temperature and Wood Powder Size on Mechanical Properties of Wood Plastic Recycled Composite

In this study, wood (cedar) powder ranging from 53 µm to 1 mm sizes, recycled polypropylene (PP) / polyethylene (PE) and acid-modified PP as a compatibilization agent were used to produce a wood-plastic recycled composite (WPRC). For discussing the effects of the wood powder sizes on the mechanical properties of the WPRC, a mixing process of the wood powder and the plastics in a constant wood content of 50% weight was firstly performed by a mixing machine controlled temperature and rotation of mixing blade. And then, to obtain WPRC panels the wood and plastics mixtures were compressed in a mould under a constant pressure and a temperature for a certain holding time. WPRC specimens for mechanical tests were cut from the WPRC panels, and a tensile strength and a size-stability were acquired. The results show that the successful mixing process runs above 180°C, where the mixing torque required compounding keeps constant or slightly increases. The tensile strength of the WPRC increases when the smaller size of wood powder is used for wood/plastic compound under successful mixing conditions. It is shown from thickness change rate of specimens that mixing temperature of wood/plastic compound affects a size stability of the WPRC.

Influence of the compatibilizer/nanoclay ratio on final properties of polypropylene matrix modified with montmorillonite-based organoclay

The use of nanoclays as additives for polymer matrices requires, in some cases (with non-polar matrices) the use of a compatibilizer agent which will act as a bridge or permanent buffer for nanoclay-matrix interaction. In this research, we have worked on the improvement of mechanical and thermal properties of polypropylene matrices by adding montmorillonite based nanoclays (MMT) which have been previously modified with an organic component (a quaternary ammonium salt modifier). In this particular case, we have worked on the optimization of the compatibilizer:nanoclay ratio. As a compatibilizer agent it has been used a propylene graft maleic anhydride copolymer (PP-g-MA) and the PP-g-MA:MMT ratio has varied from 0.25:1 to 4:1. Nanoclay dispersion and intercalation–exfoliation degree has been investigated by X-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM). Also, mechanical and thermal properties for different PP-g-MA:MMT ratios have been determined. The results show optimum dispersion and intercalation–exfoliation levels for PP-g-MA:MMT ratios close to 3:1 and 4:1 and also we can observe a slight increase in mechanical and especially in thermal properties for similar ratios.

Rheological evaluation of polymer-modified asphalt binders

Currently, the most used polymer for asphalt binder modification is the thermoplastic elastomer styrene butadiene styrene (SBS) and aromatic oil is commonly added to the mixtures to improve their compatibly. This paper proposes the use of oil shale from sedimentary rock as a compatibilizer agent for polymer-modified asphalt binder (PMB). PMBs were produced by mixing a bitumen with a linear SBS copolymer (3.5% (w.w-1)) using two oil shale contents (2 and 4%) and petroleum aromatic oil to evaluate comparatively the effect of the compatibilizer agent on the SBS PMB properties. The rheological characteristics of the SBS PMBs were analyzed in a dynamic shear rheometer (DSR) and the morphology accessed by fluorescence optical microscopy. The viscoelastic behavior of the samples corroborated the results for the classical properties and varied according to the sample morphology and composition. The results indicate that the aromatic and shale oils have similar effects on the microstructure, storage stability and viscoelastic behavior of the PMBs. Thus, shale oil could be successfully used as a compatibilizer agent without loss of properties or could even replace the aromatic oil. Following the Superpave methodology it was observed that the linear- and radial-SBS PMBs and linear-SBS PMB with 2% of shale oil can be used up to 70 °C, and the linear-SBS PMBs with 4% of shale oil or 2% of aromatic oil can be used only up to 64 °C.

Molecular orientation of extruded PET/LCP blend films. II. X‐ray pole figures

AbstractThe crystalline uniaxial molecular orientation of two liquid crystalline polymers (LCPs), Vectra®A950, and Rodrun®LC5000, blended with poly(ethylene terephthalate) (PET) was obtained from wide angle X‐ray pole figures. The blends films were produced by extrusion using a twin screw extruder with a slit die. The molecular orientation was evaluated along the transverse section of the films and as a function of the blends composition. The influence of a compatibilizer agent on the LCPs orientation was also analyzed. It was found that the orientation of both LCPs in the pure LCP films was high, highest in the draw direction but variable along the transverse section of the extruded films; in this last case, it was higher at the position where the shear rate was maximum. However, a drastic orientation decrease in both LCP's phases was observed in the films made of PET/LCPs blends. The maximum orientation effects were observed for the blend with 5 wt % of LCP content and also at the position where the shear rate was the highest. The Vectra®A950 LCP, as a pure material and in the blend with PET, orient more effectively than the Rodrun®LC5000 LCP in the films produced at the same processing conditions. The results showed that the use of a compatibilizer agent decreased the LCP orientation and were in accordance with previous studies using polarized infrared spectroscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Effect of the Amount and Funtionalization Grade of PPgMA Compatibilization Agent in Polypropylene/clay nanocomposites

Polypropylene-organoclay nanocomposites were prepared by melt processing via twin-screw extrusion of three components: PP, maleic anhydride modified polypropylene oligomers (PPgMA) and clays modified by octadecylammonium for the purpose of evaluating the effect of the amount of the grafted compound of the PP on the mechanical properties. Two ways were used to compatibilize the PP and nanoclay. First, varying the PPgMA percentage on the nanocomposite, and secondly its degree of functionalization. The rheological and mechanical properties were studied in relationship to the microstructure of the nanocomposites varying both parameters. X-ray diffraction was used to detect the formation of nanocomposites and the transmission electron microscopy (TEM) was used to characterise the dispersion of the organoclay.

Effect of wood filler treatment and EBAGMA compatibilizer on morphology and mechanical properties of low density polyethylene/olive husk flour composites

This paper deals with plastic-wood composites based on low density polyethylene (LDPE) and olive husk flour (OHF). The problem of incompatibility between the hydrophilic wood filler and the LDPE hydrophobic matrix was treated by two methods: a chemical modification of the olive husk flour with maleic anhydride to esterify the free hydroxyl groups of the wood components and the use of a compatibilizer agent, i. e. an ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA) terpolymer. The changes in the structure, the morphology, and the properties resulting from these treatments were followed by various techniques, especially FTIR spectroscopy, scanning electron microscopy (SEM), tensile meas- urements and water absorption. The experimental results indicated that both methods, i.e. the chemical treatment of the olive husk flour with maleic anhydride and the inclusion of EBAGMA terpolymer, improved the interactions between the two composite components and promoted better dispersion of the filler in the matrix. Moreover, ultimate tensile properties were also increased. However, the use of EBAGMA terpolymer as compatibilizer produced better enhancement of the properties of LDPE/OHF composites compared to those treated with maleic anhydride.

A comparative study of effect of compatibilization agent on untreated and ultrasonically treated waste ground rubber tire and polyolefin blends

The development of thermoplastic elastomer blends from waste tire powder and two polyolefins, Viz. maleic anhydride grafted polypropylene and LDPE, was studied. The polymer blends were processed using a twin-screw extruder equipped with a well-designed screw configuration. The blends studied contained a dispersed phase of waste rubber powder obtained from waste tire in a thermoplastic matrix. The effect of ultrasonic treatment on the rubber powder was compared. Contrary to our expectation, ultrasonically treated samples gave poor mechanical properties compared to untreated samples. Significant improvement in the mechanical properties was obtained with the addition of maleic anhydride-grafted styrene-ethylene-butylene-styrene (SEBS-g-MA) as a compatibilizer in treated and untreated waste tire powder / polyolefin blends.

Molecular orientation of extruded PET/LCP blend films. Part I: Polarized infrared spectroscopy

AbstractThe polarized infrared (IR) spectroscopy technique was used to evaluate the surface uniaxial molecular orientation of films of poly(ethylene terephthalate) (PET), two thermotropic liquid crystalline polymers (LCPs), Vectra®A950 and Rodrun®LC5000, and their blends obtained by extrusion. The molecular orientation of the LCP and of the crystalline and amorphous PET phases in the draw direction was evaluated along the transverse section of the films and as a function of the blend composition. A compatibilizer agent was used to improve the interfacial adhesion between the PET and LCPs. The results showed that the surface molecular orientation of both LCPs was very high along the draw direction. However, when blended, the orientation of the LCP phase decreased drastically, it was dependent of its content and varied along the transverse section of the extruded films. The maximum orientation was observed in the blend with 5 wt % LCP content and at the position where the shear rate was maxima. The LCP Vectra®A950 showed higher orientation than the Rodrun®LC5000, as a pure material and as blended. For the PET phases, an alignment of the amorphous phase in the draw direction due to the presence of LCP and compatibilizer agent was observed. The crystalline phase of PET, however, showed no significant orientation in the draw direction. The compatibilizer agent proved efficient for both PET/LCP systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2241–2248, 2006