Presence Of Maleic Anhydride Grafted Polypropylene Research Articles

Valorization of pineapple peel waste and sisal fiber: Study of cellulose nanocrystals on polypropylene nanocomposites

AbstractThe present study focuses on the isolation and characterization of the cellulose nanocrystals (CNCs) from the pineapple peel waste (PPW) (agro‐waste) and sisal fiber (SiF) (natural fiber) employing the acid hydrolysis method, and its comparison with the commercially available CNCs (CNC‐C). Furthermore, the CNCs from PPW, SiF, and CNC‐C were subjected to transmission electron microscopy (TEM), Fourier transform electron microscopy, X‐ray diffraction, particle size distribution, and zeta potential analysis. The studied properties of the isolated CNCs are considerably different from the PPW and SiF. The CNCs so formed have been estimated by TEM to be around 10–40 nm wide and length of several micrometers. Fourier transform electron microscopy studies described the removal of the noncellulosic components like lignin, hemicellulose, and pectin substances from the base materials in both the cases by employing acid hydrolysis method. Additionally, nanocomposites of CNC isolated from PPW along with polypropylene (PP) matrix were fabricated using melt blending method followed by injection molding. Maleic anhydride grafted PP (MAPP) acts as a compatibilizer for improving the dispersibility of hydrophilic CNC within the nonpolar PP matrix. The addition of CNC (3 wt%) along with MAPP at 5 wt% showed optimum tensile strength and modulus to the tune of 10.39 and 25.53%, respectively, when compared to their counterparts without MAPP. Dynamic mechanical analysis revealed an increased stiffness of PP in its nanocomposite system due to the addition of CNC. Scanning electron microscopy studies revealed uniform distribution of CNC within the nonpolar PP matrix in the presence of MAPP.

Influence of cellulose nanocrystal/sisal fiber on the mechanical, thermal, and morphological performance of polypropylene hybrid composites

Polypropylene (PP)/sisal fiber (SiF)/cellulose nanocrystals (CNC) hybrid composites were prepared at a variable weight percentage of SiF/CNC loading (29:1, 27:3, 25:5, and 23:7) using melt-blending technique followed by injection molding. The dispersion of the CNCs and SiFs within the nonpolar PP matrix was enhanced by using maleic anhydride grafted PP (MAPP) as a compatibilizer. Furthermore, the mechanical properties like tensile, flexural, and impact properties of the hybrid composites were evaluated. High tensile strength and modulus of 47.02 MPa and 2820.26 MPa, respectively, were observed for the hybrid composite with the incorporation of SiF/CNC (27:3 wt%) in the presence of 5 wt% MAPP. Additionally, an increment of 30.87% and 14.81% was observed for corresponding flexural strength and modulus as compared to their counterparts without MAPP. The elastic moduli obtained experimentally were compared with the theoretical elastic moduli using Cox–Krenchel and Ouali model in combination with the Halpin–Tsai model. Surface morphology by field emission scanning electron microscopy observed that the CNCs and SiFs were well dispersed within the PP matrix in the presence of MAPP. Differential scanning calorimetry thermograms showed no measurable changes in the melting temperature (Tm) of PP in PP hybrid composites; however, an increment in the crystallization temperature (Tc) was observed. The thermogravimetric analysis confirmed the enhancement in the thermal stability of PP hybrid composites due to the synergistic effect of hybridization within the PP matrix. Partial substitution of CNCs along with SiFs within the matrix polymer shows an increment in the stiffness of the hybrid composites as evident by dynamic mechanical analysis.

High flow polypropylene/SEBS composites reinforced with differently treated hemp fibers for injection molded parts

Polypropylene/hemp fibers (PP/HF) composites for injection molded car parts show several advantages compared to similar composites containing glass fibers (GF), however they have low impact strength, tensile strength and modulus. Here, hemp fibers modified by alkali and alkali-silane treatment were used to reinforce a polypropylene matrix modified with maleic anhydride grafted polypropylene (MAPP) and SEBS. The addition of HF in PP modified with MAPP and SEBS has increased not only the tensile strength and modulus (by 45% and 230%) but also the impact strength. Double tensile strength and triple Young's modulus were obtained in PP composites with alkali-silane treated HF (HFs) in the presence of MAPP and SEBS. Similarly, the HFs led to a significant increase of storage modulus, with about 100% at room temperature and with about 200% at 120 °C. Moreover, the onset degradation temperature increased with 51 °C for HFs containing composites compared to neat PP. PP/HFs composites modified with MAPP and SEBS showed improved mechanical and thermal properties, being considered as a viable alternative to PP/GF composites for injection molded parts in the automotive industry.

Effect of coupling agent on durian skin fibre nanocomposite reinforced polypropylene

This paper reports on the development of a composite-based natural fiber to reduce the reliance on petroleum-based product in order to amplify environmental awareness. The production of Durian Skin Nanofiber (DSNF) was conducted using biological fermentation method via rhizopus oryzae in order to obtain the nano dimension of the particle size. Polypropylene (PP) and DSNF were produced using Haake internal mixer via melt blending technique. The significant effect of maleic anhydride grafted polypropylene (MAPP) on the properties of PP/DSNF nanocomposite was investigated to study its mechanical properties which are tensile strength and thermal stability using thermogravimetric (TGA) and differential scanning analysis (DSC). The tensile property of PP nanocomposites increased from 33 MPa to 38 MPa with the presence of MAPP. The addition of MAPP also increased the thermal stability of PP/DSNF nanocomposite where the char residue increased by 52%. Besides that, the thermal degradation of PP/DSNF and PP/DSNF-MAPP were higher than PP where they exerted higher amount of weight loss at an elevated temperature. The percentage of crystallinity, %Xc, of PP nanocomposites improved with the addition of MAPP by 35% based on the differential scanning calorimetry (DSC) result. The SEM analysis showed that the PP/DSNF-MAPP exerts ductile fracture while PP/DSNF exerts brittle fracture.

Mechanical and Morphological Properties of Meranti Wood Flour Filled Polypropylene Composites

Wood plastic composites (WPC) have been produced by compounding meranti wood flour (WF) with polypropylene (PP) copolymer using a twin-screw extruder. The meranti WF content was varied from 30 to 60 wt.%. The mechanical properties, i.e. tensile, flexural and impact of the composites were determined on injection-molded specimens. The tensile fractured surfaces were used to study the morphological properties of the composites. The result shows that the increment in WF content has given a significant improvement in modulus properties but at the expense of strength and toughness properties. A commercial maleic anhydride grafted polypropylene (MAPP) compatibilizer at 5 wt.% was incorporated into the PP40/WF60 formulation. The strength, stiffness and toughness properties were improved significantly in the presence of MAPP. The morphology of the composites was studied by scanning electron microscopy (SEM). The improvement of the fibre-matrix adhesion between the WF and PP matrix as revealed by SEM is believed to be one of the major reasons for the improved mechanical properties.

Flame‐Retardant Polypropylene/Multiwall Carbon Nanotube Nanocomposites: Effects of Surface Functionalization and Surfactant Molecular Weight

Flame‐retardant polypropylene (PP)/carbon nanotubes (CNTs) nanocomposites influenced by surface functionalization and surfactant molecular weights are studied. 3‐Aminopropyl‐triethoxysilane (APTES) is utilized to modify the CNTs (f‐CNTs), and maleic‐anhydride‐grafted PP (MAPP) with two molecular weights ( of 800 and 8000 g mol−1) is used to further improve the dispersion of f‐CNTs in the PP matrix. Thermal gravimetric analysis (TGA) and microscale combustion calorimetry (MCC) reveal that the molecular weight of MAPP directly affects the thermal stability and flammability of PP/f‐CNTs PNCs: both MAPP polymers ( of 800 and 8000 g mol−1) increase the thermal stability of PP; however, the heat release rate of PP/f‐CNTs is reduced in the presence of MAPP ( of 800 g mol−1) and increased in the presence of MAPP ( of 8000 g mol−1). MAPP ( of 800 g mol−1) also results in a lower viscosity of the PP/f‐CNTs PNCs compared with pure PP. image

Dynamic-mechanical analysis and SEM morphology of wood flour/polypropylene composites

A study was conducted to investigate the effects of compatibilizers, including Maleic anhydride grafted polypropylene (MA-PP) and maleic anhydride grafted ethylene-propylene-diene copolymer (MA-EPDM), on wood-flour/polypropylene (WF/PP) composites. WF/PP composites were prepared by direct extrusion profiles using a twin-screw/single-screw extruder system. DMA analysis showed that the loss factor of composites decreased and the storage modulus improved in the presence of MA-PP, which indicated much better interfacial adhesion between the PP matrix and wood flour filler than in the absence of compatibilizer. Morphological feature based on SEM observation showed that MA-PP and MA-EPDM improved the dispersion of the wood particles in the plastic matrix. MA-EPDM is a soft segment, although it improved the interfacial adhesion, storage modulus decreases with adding of MA-EPDM. As compatibilizer of wood-flour/polypropylene composites, both DMA analysis and SEM feature proved that MA-PP was superior to MA-EPDM.

Micro- and nano-structure in polypropylene/clay nanocomposites

Polypropylene (PP)/clay nanocomposites prepared by melt blending using different clays and coupling agents based on maleic anhydride-grafted PP (MA-PP) were studied. Clay dispersion using field emission gun scanning electron microscope (FEG-SEM) and transmission electron microscopy (TEM), and PP matrix morphology were characterized. Clay dispersion was improved in the presence of MA-PP, as shown by the higher particles surface density (number of particles/mm 2) at all micro-, sub-micro- and nano-levels. The PP spherulite diameter was affected by both the presence of MA-PP and clay dispersion. Clay intercalation, characterized by both complementary X-ray diffraction (XRD) and TEM, was greatly influenced by the characteristics of MA-PP. The use of low molecular weight ( M w) MA-PP led to a good and uniform intercalation but with no further possibility to exfoliation. The use of higher M w MA-PP led to a heterogeneous intercalation with signs of exfoliation. The crystallization behavior of nanocomposites was studied by differential scanning calorimetry (DSC). When fine clay dispersion was achieved with MA-PP, clay-nucleating effect was limited and lower crystallization temperature and rates were observed. It was also shown by wide angle X-ray diffraction (WAXD) that clay induced some orientation of α-phase PP crystallites.

Performance of Rubberwood Fiber–Thermoplastic Natural Rubber Composites

Rubberwood fiber–thermoplastic natural rubber (RWF–TPNR) composites were prepared and evaluated in this study. The RWFs were supplied in the form of thermomechanical pulp (TMP) from the Hume Fiberbord Company in Malaysia. The fibers were screened to 0.5–1 mm sizes and blended with TPNR and maleic anhydride–grafted polypropylene (MAPP) as a compatibilizer in the internal mixer of Brabender Plasticorder machine. The mechanical, thermal properties and morphology of the composites were investigated by tensile, impact, flexural, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscope (SEM). The results showed that the tensile strength and Young's modulus increased, while tensile strain and impact strength decreased with increasing of fiber loading. Thermogravimetric analysis showed an increasing degradation temperature of the samples with RWF. On the other hand, SEM micrographs showed good adherence between fibers and matrix with the presence of MAPP.

Structure–property relationship of modified polypropylene–polycaproamide fiber

AbstractThe effect of the addition of polyamide on the structure and properties of polypropylene fiber has been studied. Although a good fiber is obtained with a composition containing only a very low concentration of polycaproamide in polypropylene, the increase in polyamide content decreases the drawing strength of the mixed polymer melt due to sudden lowering of melt viscosity and strength. The poor melt strength of the studied polymer mixture is attributed to increased heterogeneity induced in the system with increased concentration of polyamide. Use of an effective interphase modifier, maleic anhydride‐grafted polypropylene, however, was found to improve fiber properties of the studied polymer mixtures even with a very high concentration of polyamide as the dispersed phase. Thus, addition of a 1–4 wt % interphase modifier facilitates the formation of good fiber even with 30 wt % polycaproamide in the blend. This improvement is attributed to the improved dispersity of polyamide in the polypropylene matrix as well as improved phase compatibility due to the formation of a chemically modified polyamide during melt extrusion in the presence of maleic anhydride‐grafted polypropylene.