Addition Of Maleic Anhydride Grafted Polypropylene Research Articles

Enhanced High-Performance iPP/TPU/MWCNT Nanocomposite for Electromagnetic Interference Shielding.

The rapid development of electronic communication technology has led to an undeniable issue of electromagnetic pollution, prompting widespread attention from researchers to the study of electromagnetic shielding materials. Herein, a simple and feasible method of melt blending was applied to prepare iPP/TPU/MWCNT nanocomposites with excellent electromagnetic shielding performance. The addition of maleic anhydride-grafted polypropylene (PP-g-MAH) effectively improved the interface compatibility of iPP and TPU. A double continuous structure within the matrix was achieved by controlling the iPP/TPU ratio at 4:6, while the incorporation of multi-walled carbon nanotubes endowed the composites with improved electromagnetic shielding properties. Furthermore, by regulating the addition sequence of raw materials during the melt-blending process, a selective distribution of carbon nanotubes in the TPU matrix was achieved, thereby constructing interconnected conductive networks within the composites, significantly enhancing the electromagnetic shielding performance of iPP/TPU/MWCNTs, which achieved a maximum EMI shielding efficiency of 37.8 dB at an iPP/TPU ratio of 4:6 and an MWCNT concentration of 10 wt.%.

The effect of maleic anhydride grafted polypropylene addition on the degradation in the mechanical properties of the PP/wood composites

This work focuses on studying the influence of coupling agents on the degradation in the mechanical properties of Polypropylene (PP)/wood composites. Maleic anhydride polypropylene (MAPP) was used as a coupling agent between the wood flour and PP matrix. As the coupling agent plays an important role in the stability of the WPC, a 10 wt% wood flour was mixed with PP granules along with a UV stabilizer and varying percentages (1, 3, 5 wt%) of MAPP in a twin-screw extruder to obtain PWC granules. The composite granules were injection molded to produce tensile samples for the mechanical characterization of the composites. To test the environmental degradation of the PWCs, the tensile samples were exposed to the environmental conditions for 0, 336 h (14 days), and 672 h (28 days) prior to testing. After the specified exposure time, the samples were mechanically characterized using tensile testing. The degradation characteristics of the WPCs were quantified in terms of the failure strains of the composite with exposure time. The experiments were designed, and various analyses, including ANOVA, regression equation, and prediction tests, were carried out to investigate the impact of parameters on the failure strain of the PWCs. Moreover, the study aimed to examine the effect of parameters such as MAPP and time, on the failure strain of the composites. From the experimental results, it is concluded that the composites containing 1 wt% of MAPP showed superior retention in the degradation of composites when compared with 3 and 5 wt% MAPP content.

Effect of the melt flow index of compatibilizer on the melt processing and properties of highly filled magnesium hydroxide/linear low density polyethylene composites

AbstractThe application of highly filled composites is limited by their poor processing and rheological properties due to the high loading of fillers. One possible solution to this problem is to use maleic anhydride grafted polypropylene (MAPP) with high melt index as compatibilizer and lubricant. Herein, magnesium hydroxide (MH)/linear low‐density polyethylene (LLDPE) composites with 60 wt% of MH were prepared using MAPP with three different melt flow indexes (MFI). The equilibrium torque and melt flow index tests show that the addition of MAPP with high MFI significantly improves the processability and flowability of MH/MAPP/LLDPE composites. The rheological studies show that it also leads to a substantial reduction in the viscosity and therefore MH/MAPP/LLDPE composites exhibit more solid‐like responses. The scanning electron microscopy shows that a transition layer is formed at the MH‐LLDPE interface. The flame retardancy test shows that the addition of MAPP slightly reduces the flame retardancy of the composites as evidenced by the reduced limiting oxygen index and increased total heat release. Cone calorimeter test shows that the simultaneous addition of MH and MAPP has a synergistic smoke suppression effect.

The effect of coupling agent on the mechanical properties of injection molded polypropylene/wheat straw composites

The objective of this work is to evaluate the effect of maleic anhydride-grafted polypropylene (MAPP) as coupling agent in polypropylene (PP)-based composites filled with ground wheat straw (WS) particles. The WS and the MAPP content in the composites was 10 wt% and 2 wt%, respectively. The samples were fabricated through melt compounding using a twin-screw extruder and then formed into dumbbell-shaped specimens by injection molding. The mechanical properties of neat PP and the composites with and without coupling were evaluated based on tensile and flexural tests and dynamic mechanical analyses (DMA). The experimental results showed that incorporating WS into the PP reduces its tensile strength by ~3 MPa, while improving its Young’s modulus by 0.14 GPa. The addition of MAPP compensated for the loss in tensile strength without affecting the modulus. Similar observations were made during the flexural tests as well, in which case, however, there was no loss revealed in the strength in the presence of WS due to the different types of load. The results of DMA analyses indicated an improved stiffness of WS-containing samples throughout the whole analyzed temperature range of 20-120 °C as a consequence of reduced chain mobility of PP caused by the stiff straw particles.

Effect of Compatibilizer on the Properties of Areca-Fiber Reinforced Polypropylene Composites

ABSTRACT Areca fiber reinforced polypropylene (PP) composites were prepared at 20%, 30%, 40%, and 50% loading levels in the presence of compatibilizing agent, MAPP (maleic anhydride grafted polypropylene). The influence of compatibilizing agent and filler concentration on the mechanical properties of the resulting composites was studied. At 50% areca fiber loading, tensile, flexural strength, and modulus of the coupled samples were found to be superior when compared to the uncoupled samples. Coupled composites exhibited effective coupling/interfacial adhesion between the surface of areca fiber and polypropylene phase as evidenced by SEM microphotographs and FTIR spectroscopy. Increase in fiber percentage led to an increase in brittleness and stiffness of composites. A considerable increase in strength was noticed upon the addition of compatibilizing agent, due to proper incorporation of areca fiber into the polypropylene matrix and the efficient transfer of load from matrix to the fiber. Higher moisture absorption in case of composites with higher fiber content was found. Addition of MAPP reduces the percentage of water absorption as a result of encapsulation of areca fiber. Areca fiber can be effectively utilized to develop artificial wood with better properties to replace natural wood as a waste-to-wealth approach.

Molecular-scale deformation of glass-fiber-reinforced polypropylene probed by rheo-optical Fourier transform infrared imaging combined with a two-trace two-dimensional correlation technique

The molecular-scale deformation behavior of glass-fiber-reinforced polypropylene was probed by a newly developed rheo-optical Fourier transform infrared (FTIR) imaging technique combined with two-trace two-dimensional correlation mapping. This technique, based on an in situ polarized FTIR microscopic analysis, revealed variations in the polymer orientation during tensile deformation. The analyses of composites containing single fibers aligned parallel and perpendicular to the elongation direction clearly revealed that the addition of maleic anhydride-grafted polypropylene (MAPP) restricts the polymer mobility at the matrix–fiber interface and inhibits interfacial debonding during the elongation process. Namely, matrix–fiber adhesion was improved by the compatibilizing effects of MAPP, which in turn contributed to enhanced mechanical properties resulting from the efficient stress transfer and reduction in fracture formation at the matrix–fiber interface. This study demonstrates that the rheo-optical technique can provide a better understanding of the reinforcement mechanism of glass-fiber-reinforced thermoplastics related to interfacial states.

Use of Organic Acids in Bamboo Fiber-Reinforced Polypropylene Composites: Mechanical Properties and Interfacial Morphology.

In obtaining wood polymer composites (WPCs), a weak interfacial bonding can cause problems during the processing and affect the mechanical properties of the resulting composites. A coupling agent (CA) is commonly used to solving this limitation. To improve the interfacial bonding between bamboo fiber (BF) and a polypropylene matrix, the effect of three organic acids on the mechanical properties and interfacial morphology were investigated. The BF/PP composites were prepared in five families: the first without CA, the second using a maleic anhydride-grafted polypropylene coupling agent, and the third, fourth, and fifth families with the addition of organic acids (OA) tricarboxylic acid (TRIA), hexadecanoic acid (HEXA), and dodecanoic acid (DODA), respectively. The use of OA in BF/PP improved the interfacial adhesion with the PP matrix, and it results in better mechanical performance than composites without CA. Composites coupled with MAPP, TRIA, DODA, and HEXA showed an increase in Young’s modulus of about 26%, 23%, 15%, and 16% respectively compared to the composite without CA incorporation. In tensile strength, the increase in composites with CA was about 190%, while in the flexural modulus, the coupled composites showed higher values, and the increase was more in composites with TRIA: about 46%. The improvement caused by tricarboxylic acid was similar to that promoted by the addition of maleic anhydride-grafted polypropylene (MAPP).

The influence of mechanical recycling on the properties of thermotropic liquid crystalline polymer and long glass fiber reinforced polypropylene

The effect of mechanical recycling on the properties of injection-molded polypropylene (PP) reinforced with thermotropic liquid crystalline polymer (TLCP) or long glass fiber (GF) has been investigated. The 30 and 50 wt% in situ TCLP and GF reinforced composites were mechanically recycled for three processing cycles, using an injection molding machine with an end-gated plaque mold. The processing temperatures used in the mechanical recycling were determined using rheological and thermogravimetric analyses to minimize the degradation of polypropylene. Recycled TLCP/PP maintained its mechanical properties, and recycling had no significant influence on its morphological, thermal, rheological, and thermo-mechanical properties. Morphological investigation illustrated the regeneration of TLCP fibrils during the mold filling process of each recycle. By the addition of maleic anhydride-grafted polypropylene (MAPP), significant improvements in the mechanical properties of TLCP/PP without impact on recyclability were observed. In contrast, the tensile strength of 50 wt% glass fiber reinforced composite decreased 30% while the tensile modulus decreased 5% after the third recycle. Glass fiber filled polypropylene exhibited significant fiber shortening and was not able to regenerate fibers in processing. Fiber length attrition during the recycling process led to the deterioration of the mechanical properties of the recycled glass filled composites.

Insight into interfacial compatibilization of glass-fiber-reinforced polypropylene (PP) using maleic-anhydride modified PP employing infrared spectroscopic imaging

We propose a technique for evaluating the compatibilization effect of maleic anhydride-grafted polypropylene (MAPP) introduced into glass fiber reinforced polypropylene by probing chemical structures using Fourier transform infrared (FTIR) microscopy. The dispersion state of MAPP in the composites was investigated by FTIR imaging constructed with integrated spectral intensity arising from carbonyl groups. MAPP was predominantly distributed around the glass fibers, due to the formation of interactions between the carbonyl groups in MAPP and the surface silanol groups on the fibers. The effects of interfacial interactions on matrix-fiber adhesion of the fiber composite were confirmed by observation of a fracture surface, using FTIR imaging, after tensile testing. The presence of polymer adhered to the fiber was detected. This revealed cohesive failure to occur in the matrix portion, attributable to improved interfacial adhesion. The addition of MAPP is therefore essential to improve matrix-filler adhesion, which contributes to enhanced strength and ductility by efficient stress transfer and prevention of fracturing at the matrix-fiber interface. This characterization technique can be utilized as a generally applicable tool to reveal the mechanisms of compatibilization of polymer composites.

Thermal, structural and dynamical mechanical properties of hollow glass sphere-reinforced polypropylene composites

In the present study, the effect of maleic anhydride grafted polypropylene (MAPP) ratio on the thermal and dynamic mechanical properties of polypropylene/hollow glass spheres (PP/HGS) composites was investigated. Hollow glass spheres content was constant at 20 wt % and MA-g-PP was set at four different levels: 1, 5, 10 and 15 wt % in PP/HGS composites. The mechanical properties of polymer composites as a function of temperature were measured using dynamic mechanic analyzer. The oxidation induction times tests and thermal properties were carried out in thermogravimetric differential thermal analyzer in order to determine thermo-oxidative performance and thermal stability of the composites. Moreover, the x-ray diffraction (XRD), the Fourier transform infrared spectrophotometry and the scanning electron microscopy were used to analyze the structural characteristics of the polymer composites. The results demonstrated that the increased MAPP content enhanced dynamic mechanical and thermal oxidative aging properties of PP /HGS composites. The addition of MAPP did not alter the crystal structure according to XRD results.

The Mechanical Properties of Sisal/PMMA and Sisal/Carbon/PMMA Biomedical Composites

Sisal, carbon, and poly-methyl methacrylate (PMMA) are the component materials that have been developed for the biomedical composite. However, characterization of the mechanical properties of the composites affected by some modified treatments is still opened for discussion. Sisal/poly-methyl methacrylate (PMMA) and sisal/carbon/PMMA composites with 30% fiber content and 6 mm fiber length were manufactured using a cold press molding at room temperature for about 60 min curing time. Tensile and bending properties of the composites were investigated by the influence of alkalization, the addition of maleic-anhydride-grafted polypropylene (MAPP) and hybridization of sisal and carbon fibers. The results indicated that the addition of MAPP (3, 5 and 10 wt. %) increases the tensile and flexural strengths of sisal/PMMA composites which are higher than the composites reinforced with alkali-treated and untreated sisal fibers. The addition of 5 % MAPP resulted in more effective improvement in mechanical properties compared to the effect of alkalization. However, a significant enhancement of tensile properties was shown by the hybridization effect of sisal and carbon with a ratio of 1:1 and 1:2 in sisal/carbon/PMMA composites. Scanning electron microscopy (SEM) of tensile fracture surfaces confirmed the presence of a functional relationship between the high mechanical strength of the composites with excellent adhesion between sisal fiber and PMMA by introducing 5% MAPP. Relatively homogeneous fiber dispersion in the matrix either sisal fibers or mixed sisal and carbon fibers within the PMMA matrix with sisal/carbon ratio of 1:2 have also contributed to the improvement of the mechanical strength. The use of alkali-treated sisal and HNO3-treated carbon fibers had promoted a remarkable increase in tensile strength of the sisal/carbon/PMMA hybrid composites.

Effect of wood particle size on selected properties of neat and recycled wood polypropylene composites

Neat polypropylene (PP)- and post-industrial recycled polypropylene (rPP)-based wood-plastic composites (WPC) were manufactured using 40% mahogany wood flour (WF). The effect of particle size (0.074 to 0.149 mm, 0.177 to 0.250 mm, and 0.400 to 0.841 mm) on the selected properties of PP and rPP composites was studied. The influence of 3% maleic anhydride grafted polypropylene (MAPP) presence in the formulation was also evaluated. Test specimens were manufactured using a combination of extrusion and injection molding processes. The density and mechanical properties, such as flexural strength, flexural modulus, tensile strength, tensile modulus, elongation at break, hardness and impact strength values were determined. Morphology of the manufactured composites was also studied using scanning electron microscopy (SEM) analysis. Results showed that the particle size, polypropylene type (neat or recycled), and presence of MAPP had important effects on WPC’s properties. Density, flexural modulus, tensile modulus, and impact strength values increased with decreased particle size regardless of the presence of MAPP. Flexural strength values increased with decreased particle size without MAPP. Regardless of particle size, addition of MAPP in composites provided higher flexural strength, flexural modulus, tensile strength, and tensile modulus values but lower elongation at break values compared to composites without MAPP.

Transcrystallization of Isotactic Polypropylene/Bacterial Cellulose Hamburger Composite.

Isotactic polypropylene (iPP) is a commonly used thermoplastic polymer with many excellent properties. But high brittleness, especially at low temperatures, limits the use of iPP. The presence of transcrystallization of iPP makes it possible for fiber-reinforced iPP composites with higher strength. Bacterial cellulose (BC) is a kind of cellulose with great potential to be used as a new filler to reinforce iPP due to its high crystallinity, biodegradability and efficient mechanical properties. In this study, the iPP/BC hamburger composite was prepared by a simple hot press and maleic anhydride grafted polypropylene (MAPP) was used to improve the interface compatibility of iPP and BC. The polarizing microscope (POM) photograph shows that BC successfully induces the transcrystallization of iPP. The differential Scanning Calorimeter (DSC) date proves that the addition of BC could improve the thermal properties and crystallization rate of the composite. Especially, this change is more obvious of the iPP/MAPP/BC. The mechanical properties of the iPP/BC composites were greatly increased. This DSC date is higher than BC; we used BC particles to enhance the iPP in our previous research. The scanning Electron Microscope (SEM) analysis intuitively shows that the interface of the iPP/MAPP/BC is more smooth and flat than the iPP/BC. The fourier Transform infrared spectroscopy (FT-IR) analysis of the iPP/BC hamburger composites was shown that a new C=O group vibration appeared at 1743 cm−1, which indicated that the hydrogen bond structure of BC molecules was weakened and some hydroxyl groups were substituted after modification which can increase the lipophilicity of BC. These results indicated that the BC fiber can easily induce the transcrystallization of iPP, which has excellent mechanical properties. Moreover, the addition of MAPP contributes greatly to the interface compatibility of iPP and BC.

Interfacial designing of PP/GF composites by binary incorporation of MAH-g-PP and lithium bis(trifloromethanesulfonyl)imide: Towards high strength composites with excellent antistatic performance

High strength polypropylene (PP)/glass fiber (GF) composites with excellent antistatic performance were prepared by binary incorporation of maleic anhydride grafted polypropylene (MAPP) and lithium bis(trifloromethanesulfonyl)imide (Li-TFSI) into PP/GF composites. Li-TFSI was used as antistatic agents and MAPP was added as the interfacial binder between GF and PP matrix. It was found that the interface between PP and GF can be tuned by the binary addition of MAPP and Li-TFSI. The mechanical properties of PP/GF composites are enhanced drastically with the addition of MAPP. However, Li-TFSI induces the decreasing of the mechanical properties with enhanced antistatic performance of the composites. The investigation showed that Li-TFSI, as a high polar agent, breaks the physisorbed silane on the glass fiber, which induces the deterioration in the strengthening effects of MAPP. At the same time, the Li-TFSI is absorbed on the surface of GF and the ions are ready to move along the GF, so the antistatic performance is achieved. The specific interactions between Li-TFSI, GF and MAPP make it possible to design the interface of PP/GF composites by the binary incorporation of MAPP and Li-TFSI. Therefore, high performance PP/GF composites with both excellent antistaticity and high strength can be achieved.

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.

무수 말레익산이 그래프트된 폴리프로필렌을 상용화제로 사용한 아이소탁틱 폴리프로필렌/세균성 셀룰로오스 복합체의 기계적/유변학적 물성

To improve the mechanical performance of isotactic polypropylene (iPP), the iPP/bacterial cellulose (BC) composites were prepared. The tensile and impact strength of the composites were maximized (38.21MPa and 2.812 KJ/m²) when maleic anhydride grafted polypropylene (MAPP) content was 7 wt%, the tensile modulus was increased with the higher MAPP content and the maximum value was 1858.39 MPa. Compared with pure iPP, the tensile strength, impact strength and tensile modulus increased by 6.32 MPa, 0.75 KJ/m², and 279.68 MPa, respectively. Compared with the control group (the sample which added BC but no MAPP added), the tensile strength, impact strength and tensile modulus increased by 5.61 MPa, 0.692 KJ/m², and 11.24 MPa, respectively. Moreover, the elongation at break of the composites was decreased. Besides, the rheological results and SEM photographs indicated that with the addition of MAPP, the compatibility of the composites was improved greatly, which demonstrated the increase of the mechanical properties of the composites.

Sustainable Biocomposites from Pyrolyzed Grass and Toughened Polypropylene: Structure-Property Relationships.

A novel class of injection-molded, toughened biocomposites was engineered from pyrolyzed miscanthus-based biocarbon, poly(octene ethylene) elastomer, and polypropylene (PP). The elastomer and biocarbon were added to the PP matrix at 30 and 20 wt %, respectively. The particle size of the biocarbon varied within two main ranges: <20 and 106–125 μm. The morphology and adhesion between the filler and the matrix were controlled by the addition of maleic anhydride grafted PP (MAPP). The composites were melt-blended and then injection-molded to tensile, flexural, and impact bars. The results showed that although the morphology of the composite is almost independent of particle size it is greatly dependent on the addition of MAPP. Two completely different morphologies, separate dispersion and encapsulated filler particles, were obtained in the presence and absence of MAPP, which was verified by atomic force and scanning electron microscopies. Model calculations based on a modified Kerner equation showed that the encapsulated filler content decreased from 64 to 8% by the addition of MAPP, which caused a major improvement in the stiffness and strength of the composites. Despite having a different morphology caused by the compatibilizer, composites with smaller particles exhibited better strength and modulus and lower impact toughness compared to those with a larger particle size. Results suggest that the failure mechanisms are mainly controlled by the local fracturing of biocarbon particles, which was more pronounced when the particle size was larger.

Effect of maleic anhydride‐grafted polypropylene on the flow orientation of short glass fiber in molten polypropylene and on tensile properties of composites

AbstractComposites of polypropylene (PP) and PP blended with maleic anhydride‐grafted polypropylene (MAPP) reinforced with short glass fibers were prepared via extrusion compounding and injection molding techniques. The fiber length did not significantly change irrespective of the presence of MAPP after compounding and injection molding. However, the tensile strength of PP/fiber showed significant improvement after MAPP addition. The interfacial shear strength between PP and fiber increased with the addition of MAPP. Examination of the failure surface of a dumbbell specimen after tensile testing confirmed that the fiber highly orientated in the flow direction in the PP/MAPP matrix. The tensile strength enhancement was attributed to the improvement of the interfacial shear strength between PP and fiber. Moreover, in the injection molding process, there was high orientation of the fiber in the flow direction when there was MAPP. We concluded that the presence of MAPP causes increased orientation of the fiber.

Hemp fiber reinforced polypropylene composites: The effects of material treatments

Abstract Natural fiber reinforced thermoplastic matrix composites have been increasingly used in semi-structural applications in automotive applications because of their good specific strength and modulus, low carbon footprint and recyclability. This research work studies the effects of material treatment(s) on the mechanical behaviors of hemp fiber reinforced polypropylene (PP) composites. The material treatment(s) are realized by chemically treating the hemp fiber with different concentration NaOH and/or adding maleic anhydride grafted polypropylene (MAPP) to the PP matrix. The purpose of the material treatment(s) is to enhance the bonding between the hemp fibers and the polypropylene matrix which otherwise has low surface energy and limited bonding. The mechanical behaviors are investigated with different combinations of material treatment(s) such as 5 wt% MAPP, 5% NaOH treated hemp fiber, 10% NaOH treated hemp fiber, and 5% NaOH + 5 wt% MAPP. 15 wt% and 30 wt% hemp fiber loadings are used in the composites with these material treatments. It is found that the material treatment(s) result(s) in composites with better mechanical properties compared to the composites without any treatment(s). The composites with 5 wt% MAPP addition show the best mechanical properties.

Dependency of the Mechanical Properties of Sisal Fiber Reinforced Recycled Polypropylene Composites on Fiber Surface Treatment, Fiber Content and Nanoclay

The developments of new materials are increasing, especially in the automobile, aerospace, aviation and construction industries. The traditional materials are being replaced with nanocomposites materials due to its superior properties. In this research, chemically treated sisal fiber (SF) reinforced recycled polypropylene (rPP) nanocomposites were prepared. The SF was blended with the rPP at four different loading; 10, 20, 30 and 40 wt%, while nanoclay was added for 1, 3 and 5 wt%. Maleic anhydride grafted polypropylene (MAPP) was used as a compatibilizer. Fiber surface modification led to enhanced interfacial adhesion between the SF and the rPP matrix. The results also showed that fiber modification, addition of MAPP and nanoclay inclusion, led to an improvement in the mechanical properties and reduced the rate of water absorption. With increased fiber loading, addition of MAPP and nanoclay; tensile strength, Young’s modulus and impact resistance of the SF/rPP nanocomposites was observed to have increased.