Addition Of Maleic Anhydride Grafted Polypropylene Research Articles

Enhanced wear performance of nylon 6/organoclay nanocomposite by blending with a thermotropic liquid crystalline polymer

AbstractA new approach for improving the wear performances of nylon 6 (PA6)/clay nanocomposites was examined in this study. Two hybrid nanocomposites were prepared by melt blending a thermotropic liquid crystalline polymer (TLCP) and a well‐dispersed PA6/clay nanocomposite, but with and without the incorporation of maleic‐anhydride grafted polypropylene (MAPP) as compatibilizer. The addition of MAPP improved the compatibility between TLCP and matrix and thus enhanced the fibrillation of dispersed TLCP phase. Wear‐testing results revealed that the wear resistance of the compatibilized hybrid nanocomposite could be improved effectively, as indicated by the low values of specific wear rate and frictional coefficient, especially under high‐normal load (i.e., 80 N). Based on the characterization on the worn damage and the debris, it was suggested that abrasive wear was the main‐damage mechanism for all the materials under investigation, except for the compatibilized hybrid nanocomposite. For this system, the wear damage was caused by a combination of abrasive and adhesive wearing because of the formation of transfer film on the counter pin surface from the wear debris. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

Thermomechanical and Rheological Behaviours of Waste Glass Fibre-Filled Polypropylene Composites

The composites between the reinforced glass fibre wastes obtained from surfboard manufacturing industry and polypropylene were developed for value adding and environmental reasons. The thermomechanical and rheological behaviours of the composites were investigated. Glass fibre contents were varied from 5 to 30 wt%. The effects of maleic anhydride grafted polypropylene (MA-PP) compatibilizer on the behaviours were also determined. The results revealed that the addition of glass fibre was able to reduce the heat of fusion of the composite. Additionally, the tensile and flexural properties were increased with increasing the glass fibre contents following the rule of mixtures. The addition of MA-PP led to enhance tensile and flexural properties due to the improvement of the adhesion between matrix and glass fibre, which is correlated with morphological observations. From the rheological studies, the apparent flow activation energy revealed that the addition of glass fibre decreased the fluidity of the molten composite materials; however, it could be slightly improved by using MA-PP.

Dielectric Behavior of Maleic Anhydride Grafted Polypropylene (MAgPP) Modified Sisal Fiber Reinforced PP Composites

ABSTRACT Sisal fiber reinforced polypropylene composites having different weight percent sisal fiber with and without Maleic anhydride grafted polypropylene (MAgPP) have been developed by melt mixing method. Dielectric properties such as ϵ′, tanδ, and a.c. conductivity of sisal fibers reinforced polypropylene composites with and without MAgPP have been determined. Dielectric constant, tan δ, and a.c. conductivity increases with increase in temperature at different frequencies. 10 wt% sisal fiber addition to PP gave two tanδ peaks. First peak appears at 90°C, which is similar to 5 wt% sisal fiber PP composite. Another peak appears at 105°C, which is due to the sisal fiber. MAgPP addition to sisal-PP composite suppresses the first 90°C peak. There is a peak that appears at 123°C, 126°C, 135°C, and 140°C in 1 phr (parts per hundred) MAgPP added sisal-PP composite. On adding 2 phr maleic anhydride grafted polypropylene (MagPP) to 5wt% sisal-PP composite the peak appears at 125°C, 128°C, 132°C, and 135°C. Peak is shifted to higher temperature side due to the improved bonding between the sisal fiber and PP matrix. The relaxation time values calculated at 70°C for sisal fiber/PP composites with and without MAgPP show that addition of sisal fiber decreases the relaxation time due to shortening of PP chains. Addition of low concentration of coupling agent increased the relaxation time and further increase of MAgPP concentration decreased the relaxation time value, increase is due to increased bonding between sisal fiber and polypropylene chains. Better bonding between fiber and polypropylene would have created hindrance in the movement of the dipoles, which would have increased the relaxation time.

Effects of dynamical cure and compatibilization on the morphology and properties of the PP/epoxy blends

In this paper, effects of dynamical cure and compatibilization on the morphology and properties of the PP/epoxy blends were studied. The addition of maleic anhydride-grafted polypropylene (MAH-g-PP) and dynamical cure of epoxy by dicyanamide give rise to decrease the average diameter of epoxy particles in the PP/epoxy blends. The epoxy particles in the PP/epoxy blends act as effective nucleating agents, accelerating the crystallization of PP component. The dynamical cure and compatibilization increase the kinetic constant K(T) of PP crystallization in the PP/epoxy blends. Dynamical cure of the epoxy resin leads to an improvement in the modulus and strength of the PP/epoxy blends, and the addition of MAH- g-PP results in an increase in the impact strength. Dynamic mechanical thermal analysis (DMTA) results indicate that the addition of MAH-g-PP improves the compatibility between PP and epoxy resin, and the storage modulus of the PP/epoxy blends increase by dynamical cure. Thermogravimetric analysis (TGA) results show dynamical cure of epoxy and addition of MAH-g-PP improved the thermal stability of the PP/epoxy blends. Wide-angle X-ray diffraction (WAXD) analysis shows that the PP/epoxy blends have the same crystalline structure as pure PP, indicating dynamical cure and compatibi- lization do not disturb the crystalline structure of the PP/epoxy blends.

Influence of Different Endothermic Foaming Agents on Microcellular Injection Moulded Wood Fibre Reinforced PP Composites

Microcellular wood fibre reinforced polypropylene composites, a new development using bio-fibre strengthened plastic, were prepared in an injection moulding process. The influence of three different endothermic chemical foaming agents was examined. The effects of various concentrations (1 to 4 wt.% of the composites) of the chemical foaming agent on the properties of the composites was studied with a view to establishing the concentration-structure-property relationships for these materials. The influence of wood fibre type (hard wood and soft wood) on the microcellular structure and physico-mechanical properties of the composites was also investigated. Microcell morphology (cell size, shape and distribution) was observed using scanning electron microscope. The chemical substance of different endothermic foaming agent affected the microcellular structure of hard and soft wood fibre-PP composites. Endothermic foaming agent with chemical substance polymeric microsphere (ESC 5313) showed finer microcellular structures compared to other foaming agents and 4 wt.% content of chemical foaming agent exhibits finer microcellular structures than the other contents. The reinforcing of soft wood fibre showed significantly finer microcellular structures than the hard wood fibre reinforcements. Density reduced maximum 30% and decreased up to 0.721 g/cm3 at soft wood fibre 30 wt.% content with coupling agent maleic anhydride grafted polypropylene (MAH-PP). With the addition of MAH-PP, specific tensile strength and specific flexural strength increased maximum 60% and 55% respectively with foaming agent ESC 5313 at soft wood fibre 30 wt.% content.

Effect of coupling agent on abrasive wear behaviour of chopped jute fibre-reinforced polypropylene composites

In this paper, studies have been conducted to investigate the abrasive wear behaviour of jute fibre-reinforced polypropylene composites. Effect of addition of maleic anhydride-grafted polypropylene (MA-g-PP)-coupling agent by two different approach, sliding distance and load on abrasive wear performance of jute fibre–PP composites has been determined by using a SUGA abrasion tester. Use of coupling agent gives better wear resistance as compared to without the use of coupling agent. It has also been found that addition of MA-g-PP coupling agent during melt mixing gives better wear resistance as compared to the jute PP composites having MA-g-PP solution-treated jute fibres, which has been explained on the basis of highest thermal stability of jute–PP Composite having melt-mixed MA-g-PP. Abrasive wear performance of the composites has been explained with the help of surface microstructures of worn surfaces.

Influence of surface modification of fillers and polymer on flammability and tensile behaviour of polypropylene-composites

An intumescent system consisting of ammonium polyphosphate (APP) as an acid source and blowing agent, pentaerythritol (PER) as a carbonific agent and natural zeolite (clinoptilolite, Gördes II) as a synergistic agent was used in this study to enhance flame retardancy of polypropylene (FR-PP). Zeolite was incorporated into flame retardant formulation at four different concentrations (1, 2, 5, and 10 wt%) to investigate synergism with the flame retardant materials. Filler content was fixed at 30 wt% of total amounts of flame retardant PP composites. Zeolite and APP were treated with two different coupling agents namely, 3-(trimethoxysilyl)-1-propanethiol and (3-aminopropyl)-triethoxysilane for investigation of the influence of surface treatments on mechanical properties and flame retardant performance of composites. Maleic anhydride grafted polypropylene (MAPP) was used for making polypropylene hydrophilic. Flammability of FR-PP composites was measured by the determination of limiting oxygen index (LOI). The LOI values reached to a maximum value of 41% for mercapto silane treated APP:PER (2:1) PP composite containing 5 wt% zeolite. The tensile strength of composites was increased by the addition of MAPP and elongation at break of composites was increased with silane treatments.

Fibre Orientation and Mechanical Properties of Short Glass Fibre Reinforced PP Composites

The fibre orientation and distribution in short glass fibre (SGF) reinforced polypropylene (PP) composites were measured and an orientation function ( f) was introduced to describe the fibre orientation distribution. The fibre orientation distribution in the same level plane depended on the fibre position in an injection-moulded plate. The fibres close to the boundary wall of the injection cavity were parallel to the injection direction and those close to the back wall were perpendicular to the injection direction. A commercial maleic anhydride grafted PP (MAPP) was used as a compatibilizer. With the addition of MAPP, the fibre orientation distribution in PP/SGF/MAPP composites was slightly different from that of PP/SGF, but MAPP improved the interfacial adhesion between SGF and PP and consequently the mechanical properties. The use of SGF increased the tensile strength of the PP composites from 26.5 to 45.9 MPa (73% improvement), and for the PP/MAPP/SGF composite the tensile strength increased further to 55.4 MPa. The effect of SGF on the tensile strength can be expressed by a fibre efficiency factor (λσ). The SGF efficiency factor of PP/MAPP/SGF (0.198) was 45% higher than that of PP/SGF (0.137). The impact strength of PP/MAPP/SGF (64.7 MPa) was not only higher than that of PP/SGF (40.8 MPa) by 59% but also higher than that of PP (48.3 MPa) by 34%.

Maleic anhydride grafted polypropylene as a coupling agent for polypropylene composites filled with ink‐eliminated waste paper sludge flour

AbstractInk‐eliminated sludge flour (IESF), a waste residue from the recycling treatment of waste paper, is a promising new kind of filler for thermoplastic polymers with a good price/performance ratio and advantages for environmental protection. In this study, high‐impact polypropylene (PP) and maleic anhydride grafted polypropylene (MAPP) were chosen as a polymer matrix and a coupling agent, respectively, for the preparation of IESF/PP composites, and the structures and properties of the obtained composites were also investigated. The experimental results revealed that IESF not only induced the crystallization orientation of PP along the b axis but also had a restraining effect on the formation of the β phase during the recrystallization of PP from the melt; the addition of MAPP further strengthened this effect to some extent. In addition, the proper addition of MAPP was helpful for improving the thermal stability of the IESF/PP composites. With the strengthening of the interfacial interaction between the IESF and PP matrix by MAPP, the resultant efficient stress transfer from the PP matrix to the IESF particles led to increased tensile and flexural strength. However, the original greater rigidity of MAPP, with respect to PP, reduced the toughness of the composites and caused some negative effects on the impact strength and the elongation at break. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2320–2325, 2004

Mechanical Properties of Kenaf–Thermoplastic Natural Rubber Composites

Kenaf–thermoplastic natural rubber (Kenaf–TPNR) composites were developed and evaluated in this study. The kenaf was blended with TPNR and maleic anhydride-grafted polypropylene (MAPP) as a compatibilizer in an internal mixer (Brabender). The mechanical properties of the composites were investigated by tensile, impact, flexural, and morphologic properties by scanning electron microscope (SEM). The incorporation of the kenaf fiber into the TPNR matrix resulted in an improvement in the tensile strength and Young's modulus. However, the maximum strain and impact strength decreased with increased filler loading. The better performance was attributed to the addition of MAPP due to improvements in the wetting of the filler surface. The addition of MAPP produced composites with improved tensile strength, Young's modulus, and flexural stiffness. SEM was employed to investigate the fiber surface, fiber pullout, and fiber–matrix interaction of composites.

Preparation and characteristics of composites of high‐crystalline cellulose with polypropylene: Effects of maleated polypropylene and cellulose content

AbstractBinary composites of high‐crystalline fibrous cellulose with polypropylene (PP) or maleic anhydride‐grafted polypropylene (MAPP) were prepared by melt‐mixing with different contents of cellulose from 0 to 60 wt %. Ternary composites of cellulose with PP and MAPP were also prepared to investigate the effects of MAPP as a compatibilizer between cellulose and PP. Scanning electron microscopy revealed that the addition of MAPP generates strong interactions between a PP matrix and cellulose fibers: All cellulose fibers are encapsulated by layers of the matrix and connected tightly within the matrix. Thus, the tensile strength and Young's modulus of MAPP‐containing composites increase with an increase in MAPP and cellulose content, in contrast to the decrease in tensile strength of a PP‐based binary composite with an increase in cellulose. Cellulose fibers act as a nucleating agent for the crystallization of PP, which is promoted by the addition of MAPP through an increase of the crystallization temperature of PP in the composite. Accordingly, both cellulose and MAPP facilitate the thermooxidative stability of PP composites in the following order: MAPP/cellulose > PP/MAPP/cellulose > PP/cellulose > PP. Relative water absorption increases with an increase in cellulose content, decreasing with the addition of MAPP. MAPP‐containing cellulose composites have high potential for applications as environmentally friendly materials. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 337–345, 2003

The effect of a third component on the morphology and mechanical properties of liquid-crystalline polymer and polypropylene in situ composites

Maleic-anhydride-grafted PP (MAGPP) and polycarbonate (PC) were used as the third component and their effect on the morphology and the mechanical properties of in situ composites of Rodrun liquid-crystalline polymer (LCP) and polypropylene (PP) has been investigated. The addition of LCP in a PP matrix resulted in an increase in tensile modulus but a decrease in tensile strength. The addition of MAGPP as third component in the LCP/PP binary system has considerable effect on both the tensile strength and tensile strain. Furthermore, the introduction of PC in the LCP/PP binary system resulted in a significant increase in tensile modulus, tensile strength and tensile strain. The 30 wt% of PC in the LCP/PP/PC ternary system was an optimum value for the best mechanical properties. A lamella-like morphology was found at the tensile fracture surface of the LCP/PP/PC ternary system whereas it was ribbon-like structure in the LCP/PP binary system.

Control of the structure and properties of barium sulphate-filled blends of polypropylene and ethylene propylene copolymers

The structure and properties of polypropylene (PP) and ethylene propylene copolymer (EPR) blends filled with BaSO4 have been investigated. The aspect of structure control concerned was the separate dispersion of filler and rubber in the PP matrix or encapsulation of the filler in the rubber phase. The former structure prevails in the PP/EPR/BaSO4 systems, and addition of maleic anhydride-grafted polypropylene (MAPP) enhances the adhesion between the PP matrix and the filler. Encapsulation of the filler particles into the elastomer takes place when maleated EPR-rubber (EPMA) is used, and the encapsulated structure prevails even under the severe shearing conditions of injection molding. The improved matrix/filler adhesion resulted in increased yield stress and tensile strength, but decreased impact resistance. The particle size of the filler proved to be a crucial factor; below a certain particle size aggregation becomes a dominating factor. Extensive aggregation leads to the deterioration of all mechanical properties, especially to decreased impact strength.