Maleic Anhydride-grafted High-density Polyethylene Research Articles

Mechanical Properties Effect of Wood-plastic Composite by Basalt Fiber and MAPE

In order to protect biological resources, this article explores the use of tensile and bending tests and Thermogravimetry (TG), thermal differential scanning (DSC) and other experimental studies. The compatibilizer maleic anhydride grafted high-density polyethylene (MAPE) improves the mechanical properties of chopped basalt fiber (SBF, 20% by mass) and reinforces wood-plastic composites (WPC). The results show that: 1) WPC with a length of 6mmSBF, when the MAPE content is 5∼6%, its tensile breaking strength and bending strength achieve the best results, of which the breaking strength is increased by about 90% compared with pure wood plastic; (2) Since the tensile and bending strength of MAPE itself is roughly similar to HDPE, when the content of MAPE is greater than 9%, it acts as a matrix HDPE. In addition to the plasticity continues to be improved, its strength index is gradually decreasing. 3) When the MAPE content is 6%, the TG curve has the slowest thermal weight loss and the DSC has the highest melting peak temperature, which means that the composite material is difficult to melt, and the bonding between the components in the material is firm, thereby having better mechanics. The performance also confirmed the results of mechanical testing.

Cyclic Extrusion of Recycled High Density Polyethylene/Banana Fiber/Fly Ash Cenosphere Biocomposites: Thermal and Mechanical Retention Properties

AbstractDisposal of composite materials used vastly in structural applications raises the need to study the reprocessability of these systems for environmental benefits. In this paper, composites of recycled high density polyethylene (R) containing 30 wt.% banana fiber (BF)/7.5 wt.% fly ash cenospheres (FACS) were prepared with 3 wt.% maleic anhydride grafted high density polyethylene (MA-g-HDPE) as a coupling agent using twin screw extrusion followed by injection molding. The effects of thermal cycles (two times extrusion followed by injection molding) were studied on R and its composites. The samples were characterized by using tensile, flexural, izod impact tests, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetry (TGA) and dynamic mechanical analysis (DMA). The tensile and flexural properties were improved by addition of both BF/FACS into the R matrix. The percentage retention in tensile properties of R/BF/FACS(E2) biocomposites (i.e. two times extrusion followed by injection molding) is more than 80 %, while that for flexural properties is more than 90 %. This indicates that R/BF/FACS composites exhibit good retention ability in mechanical properties after subjecting to two times twin-screw extrusion followed by injection molding. DSC results revealed that repeated extrusion improved the crystallization temperature and crystallinity of the composites with a slight reduction in melting temperature. From the TGA results, it was observed that the thermal stability (e.g. Tonset) of R was reduced by the addition of BF/FACS. However, repeated extrusion showed an improvement in thermal stability of the composites.

Electrically Conductive and Flame Retardant Graphene/Brominated Polystyrene/Maleic Anhydride Grafted High Density Polyethylene Nanocomposites with Satisfactory Mechanical Properties

Electrically conductive and flame-retardant maleic anhydride grafted high-density polyethylene (MA-HDPE) nanocomposites with satisfactory mechanical properties are fabricated by melt compounding MA-HDPE with polyethyleneimine (PEI)-modified reduced graphene oxide (PEI@RGO) as the conductive nanofiller and brominated polystyrene (BPS) as the flame retardant. The modification with PEI significantly improves the interfacial compatibility and dispersion of the RGO sheets in the MA-HDPE matrix, leading to electrically conductive nanocomposites with enhanced mechanical properties. Furthermore, the addition of 25 wt% of BPS makes the nanocomposite flame-retardant with a UL-94 V-0 rating. Thus, the multifunctional RGO/MA-HDPE nanocomposites with good electrical, flameretardant, and mechanical properties would have potential applications in construction and pipeline fields.

A study of industrial lime sludge waste as filler in hybrid polymeric composites

Industrial lime sludge waste is an environmental hazard, which is usually disposed in dump yards causing pollution. This study aims to increase the viability of lime sludge (LS) by using it as filler in hybrid polymeric composites. Study of the mechanical properties of LS filled high density polyethylene (HDPE) and maleic anhydride grafted high density polyethylene (MAPE) revealed better properties of MAPE due to effective interfacial bonding at the filler-matrix boundary owing to the presence of maleic anhydride compatibilizer. LS also proved to be an effective reinforcing filler in case of short coir fibre - epoxy hybrid composites, thereby increasing their tensile strengths upon filler loading up to 9 wt %. LS improved thermal stability of the LS-coir-epoxy hybrid composites by increasing the thermal degradability and residual wt. %. However, it is observed that the addition of coir and LS in composites increased the water absorption rate of the composites significantly. Nevertheless, lime sludge proves to be an efficient filler in polymeric composites which would not only decrease pollution but also manufacturing cost of polymeric composites.

Effect of PANI on Thermal, Mechanical and Electromagnetic Properties of HDPE/LLDPE/PANI Composites

In this work, polyaniline (PANI) in emeraldine-base form, synthesized by chemical oxidation polymerization, was protonated with hydrochloric acid (HCl). Composites based on high-density polyethylene (HDPE) and linear-low density polyethylene (LLDPE) blends with PANI were prepared in molten condition using a torque rheometer. The effect of compatibilizer agent (maleic anhydride-grafted high density polyethylene, HDPE-g-MA) and different contents of PANI on the blends-based composites was also investigated. Thermal, mechanical, and electromagnetic (electric permittivity) measurements and morphological aspects of the composites were evaluated. The addition of PANI content in the composites decreases the degree of crystallinity of HDPE and LLDPE blends, which implies that PANI particles make it difficult for co-crystallization to occur in the HDPE and LLDPE, respectively. On the other hand, the addition of compatibilizer agent in the HDPE and LLDPE blends increased the degree of crystallinity. The complex parameters of permittivity in the frequency range of 8.2 to 12.4 GHz varied as a function of the PANI content in the blend. It was also observed that the compatibilizer agent increased the composite stiffness and decreased the electric permittivity values. This result shows that the increasing rigidity of the molecular structure of the polyethylene matrix hindered the dissipation of the electromagnetic energy in the sample.

Preparation and Properties of a Novel Microcrystalline Cellulose-Filled Composites Based on Polyamide 6/High-Density Polyethylene.

In the present study, lithium chloride (LiCl) was utilized as a modifier to reduce the melting point of polyamide 6 (PA6), and then 15 wt % microcrystalline cellulose (MCC) was compounded with low melting point PA6/high-density polyethylene (HDPE) by hot pressing. Crystallization analysis revealed that as little as 3 wt % LiCl transformed the crystallographic forms of PA6 from semi-crystalline to an amorphous state (melting point: 220 °C to none), which sharply reduced the processing temperature of the composites. LiCl improved the mechanical properties of the composites, as evidenced by the fact that the impact strength of the composites was increased by 90%. HDPE increased the impact strength of PA6/MCC composites. In addition, morphological analysis revealed that incorporation of LiCl and maleic anhydride grafted high-density polyethylene (MAPE) improved the interfacial adhesion. LiCl increased the glass transition temperature of the composites (the maximum is 72.6 °C).

Interfacial interaction between degraded ground tire rubber and polyethylene

The interfacial interaction between the linear low density polyethylene (LLDPE) and ground tire rubber (GTR) suffered from various degrees of degradation was investigated using the scanning electron microscopy (SEM), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC) and mechanical testing. The effect of the maleic anhydride-grafted high density polyethylene (HDPE-g-MAH) on the interaction was also investigated. The results showed that the interfacial interaction was greatly influenced by the degradation degree of ground tire rubber and the presence of HDPE-g-MAH. During the melt process, a mechanochemical reaction between LLDPE and the degraded GTR was observed. The addition of the HDPE-g-MAH promoted a more homogeneous dispersion of degraded GTR in the LLDPE, and the thermal and mechanical performance of the composites was higher than those of without HDPA-g-MAH. The degraded molecular chains and the exposed carbon black reacted with the HDPA-g-MAH, which was confirmed by the Fourier transform infrared spectroscopy (FTIR).

Conceptualizing Physical and Chemical Interactions in the Compatibilized HDPE/PA6 and HDPE/EVOH Pairs: Theoretical and Experimental Analyses

ABSTRACTPhysical/chemical interaction in blends of high-density polyethylene with polyamide 6 and polyethylene-co-vinyl alcohol compatibilized with maleic anhydride-grafted high-density polyethylene was discussed. The performance of maleic anhydride-grafted high-density polyethylene was assessed by domain size variation and interfacial adhesion examination. Analysis of impact strength elucidated physical interaction improvement by compatibilization (entanglements and hydrogen bonding), while chemical reactions between ‒OH and ‒NH (from polyethylene-co-vinyl alcohol and polyamide 6, respectively) and ‒COOH functional groups resulting from ring-opening of maleic anhydride determined interfacial adhesion reinforcement, where interfacial adhesion parameter changed from 0.75 for noncompatibilized to 0.96 compatibilized high-density polyethylene/polyamide 6, but remained unchanged for high-density polyethylene/polyethylene-co-vinyl alcohol blends, from 0.98 to 1.02.

Extrusion Blow Molding of Polymeric Blends Based on Thermotropic Liquid Crystalline Polymer and High Density Polyethylene

Abstract This work is concerned with the extrusion blow molding of polymeric blends containing thermotropic liquid crystalline polymer (TLCP) and high density polyethylene (HDPE), using a single screw extruder. The TLCP is synthesized from terephthalic acid, 4-hydroxybenzoic acid, hydroquinone and hydroquinone derivatives, the melting point of which is 280 °C. Because the TLCP is usually processed at much higher temperatures than HDPE, the thermal stability of HDPE at elevated temperature is evaluated. It is shown that HDPE is relatively stable in the processing temperature range of the TLCP used in this work (260 to 300 °C). Bottles are successfully produced from the blends containing 10, 20 and 50 wt% TLCP. The TLCP/HDPE blend bottles exhibit enhanced modulus relative to pure HDPE. However, the improvement in tensile strength is marginal. At 10 and 20 wt% TLCP contents, the TLCP phase exists as platelets aligning along the machine direction, while a co-continuous morphology is observed for the blend containing 50 wt% TLCP. To further enhance the mechanical properties of the blends, the preliminary effectiveness of maleic anhydride grafted HDPE (MA-g-HDPE) as a compatibilizer is studied. The injection molded ternary blends of TLCP/HDPE/MA-g-HDPE have demonstrated superior mechanical properties over the binary TLCP/HDPE blends, which suggests MA-g-HDPE as a potential compatibilizer for developing high performance TLCP/HDPE containers with enhanced mechanical properties.

Thermal degradation kinetics and lifetime of high-density polyethylene/poly (l-lactic acid) blends

In this work, a kinetic study on the thermal degradation of films prepared from high-density polyethylene (HDPE), poly(l-lactic acid) (PLLA) and their blends is presented. Activation energy ( Ea), order of reaction ( n) and frequency factor (ln ( A)) were studied through thermogravimetric analysis (TGA) over a temperature range of 25–600°C at four heating rates, that is, 5, 10, 15, and 20°C min−1. The TGA data were used to predict the thermal stability of the film samples, comparing the kinetic parameters obtained by three model-free isoconversional techniques and estimating the lifetime of the films. The value of Ea for neat HDPE was found to be much higher than that for PLLA, but for HDPE/PLLA blends, it was nearer to that of HDPE. An increase in Ea of 80/20 (HDPE/PLLA) blends was noticed with the addition of compatibilizer, maleic anhydride-grafted HDPE. Overall, the thermal kinetics of the polymer samples depends on fractions of their constituents, heating rates and calculation technique used. It was proved, through lifetime estimation method, that the lifetime of neat HDPE decreases by addition of PLLA. With increase in temperature, the lifetime of all samples decreased exponentially. Scanning electron microscopy studies verified that HDPE and PLLA interfaces became fairly compatible by adding the compatibilizer.

Mechanical properties of sisal fiber reinforced high density polyethylene composites: Effect of fiber content, interfacial compatibilization, and manufacturing process

In this paper, we investigated the effect of fiber content, interfacial compatibilization, and manufacturing process on the mechanical properties (tensile, impact and creep) of sisal fiber (SF) reinforced high-density polyethylene (HDPE) composites. The increase of fiber content and interfacial compatibilization with maleic anhydride grafted HDPE (MAPE) were found to improve the mechanical properties of the composites. Compared with simultaneous blending, a pre-impregnation process with the compatibilizer, namely MAPE, improved the interfacial bonding between the fibers and the matrix, which in turn improved the mechanical properties of the composites. The General Power-Law equation was used to model the creep behavior of the composites. The identified material parameters based on the creep data were used to predict the creep-recovery behavior of the composites, and good agreement was achieved between the predicted and experimental creep-recovery responses.

Influence of MA‐g‐HDPE compatibilizer content on quality and adhesion/bending strength of polyethylene/O‐MMT coating films

ABSTRACTHigh density polyethylene/organo‐modified montmorillonite composites whit various concentrations of maleic anhydride grafted high density polyethylene (MA‐g‐HDPE) as compatibilizer (5–20 wt %) have been prepared by melt process. The extruded composite powders are applied on the treated steel surfaces using spray electrostatic powder technique, followed by oven curing at various temperatures (180°C–220°C) and times (15–45 min). The surface uniformity of produced coating films is studied by scanning electron microscopy. Comparison of micrographs of the coatings shows the composite coating films are measured using standard methods. The uniformity, adhesion, and bending strength of the coating films are compared to select high performance coatings. The results indicate that the presence of 15 wt % MA‐g‐HDPE in the coatings shows the highest properties (adhesion and bending strength) and more surface uniformity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40926.

Improvement in the mechanical performance and interfacial behavior of kenaf fiber reinforced high density polyethylene composites by the addition of maleic anhydride grafted high density polyethylene

The effects of compatibilizer on the tensile, flexural and interfacial adhesion behavior of kenaf fiber reinforced high density polyethylene composites were investigated. The addition of maleic anhydride grafted high density polyethylene (MA-HDPE) as compatibilizer into the composites was found to improve the mechanical properties and the adhesion behavior of the composites. These improvements were due to the improved compatibility between matrix and fiber. 8 % MA-HDPE loading provided maximum enhancement in tensile and flexural properties when compared to the other compatibilizer contents. Meanwhile, uncompatibilized composites showed poorer mechanical properties and interfacial behavior relative to the compatibilized composites. Fourier transformed infrared spectroscopy analysis confirmed the changed chemical structures by the appearance of stretching vibration of the ester carbonyl groups (C = O) around 1725 cm−1 to 1742 cm−1 and the peak of hydroxyl group at 3327 cm−1 in the compatibilized composites. This indicates that the maleic anhydride has bonded to the kenaf fiber through esterification reaction, giving rise to strong interfacial bonding between the matrix and fiber. The improvement in the interfacial behavior was evident from the tensile fracture surface morphology using a field emission scanning electron microscopy.

Morphological factors affecting the permeation resistance of nanocomposite blend films

The micro- and nanoscale morphologies of thin nanocomposite films comprising an immiscible nylon 6/polyethylene blend reinforced with modified sodium montmorillonite were found to substantially affect water vapor transmission rates (WVTRs). Maleic anhydride-grafted high-density polyethylene was incorporated as a compatibilizer between the nylon and polyethylene phases. Preferential incorporation of an organosilicate nanoclay in the nylon phase had a secondary effect on the overall blend morphology and thermal properties. Different degrees of phase continuity in the nanocomposite blend system were studied for their effect on WVTRs by varying the relative viscosities of the polymer phases. Transmission electron and atomic force microscopy were utilized to reveal the morphologies of the nanocomposite blends. POLYM. ENG. SCI., 54:1341–1349, 2014. © 2013 Society of Plastics Engineers

Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE) Addition.

This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE) enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs). The maximum values of the specific tensile and flexural strengths areachieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

Effect of bark flour on viscoelastic behavior of high density polyethylene

The dynamic mechanical behavior of high density polyethylene (HDPE) in HDPE/bark flour (BF) composites on varying the volume fraction (Φf) of BF (filler) from 0 to 0.26 has been studied. The storage modulus decreases with increase in BF content up to Φf = 0.07, which is attributed to a pseudolubricating effect by the filler. The storage modulus for the composites at Φ f = 0.20 is higher than HDPE in all other temperature zones due to enhanced mechanical restraint by the dispersed phase. At Φf = 0.07, the loss moduli were either marginally lower or similar to that of HDPE, which is due to the ball-bearing effect of the filler as well as decrease in the crystallinity of HDPE. Above Φf = 0.07, the loss moduli were higher than HDPE. The α-relaxation region of the damping peak shifted toward the higher temperature side with increase in BF content. In the presence of the coupling agent, maleic anhydride-grafted HDPE (HDPE-g-MAH), the storage modulus values were marginally lower than those of the HDPE/BF systems. In the HDPE/BF/HDPE—g—MAH composites, the variations of the loss moduli were similar but values lower than those of the HDPE/BF systems. Damping peak shift in the α-region toward higher temperature was more than those of the HDPE/BF systems, which may be due to the hindrance to the relaxation due to an enhanced phase interaction. The values of tan δ were higher than the rule of mixture for both the composites.

Morphology and properties of nanocomposites based on HDPE/HDPE-g-MA blends

Nanocomposites formed from blends of high density polyethylene (HDPE) and maleic anhydride-grafted high density polyethylene (HDPE-g-MA) and M2(HT)2 organoclay were melt processed to explore the extent of exfoliation and the mechanical properties. Wide angle X-ray scattering (WAXS) and transmission electron microscopy (TEM) coupled with detailed particle analysis were used to determine the effect of HDPE-g-MA content and organoclay content on exfoliation and mechanical properties. As the HDPE-g-MA content increases, the global average particle aspect ratio initially increases drastically, reaches a maximum, and slightly decreases. The fraction of single platelets, however, increases at a steady rate for nanocomposites with HDPE-g-MA contents ≥25%. Relative modulus initially improves with increased levels of HDPE-g-MA, and then levels off with greater HDPE-g-MA content. Izod impact strength reaches a maximum at low HDPE-g-MA levels, decreases below the value for the pure HDPE nanocomposite, and levels off at higher HDPE-g-MA content. A composite model based on the Mori–Tanaka theory was developed to treat organoclay tactoids and single platelets as two separate types of fillers. This model gives rather good quantitative agreement between the predicted values of modulus calculated from the TEM results and that measured experimentally.

Structure and morphology of HDPE- g-MA/organoclay nanocomposites: Effects of the preparation procedures

Nanocomposites comprising high density polyethylene (HDPE) or maleic anhydride-grafted HDPE (HDMA) as the host polymers and Cloisite ® 20A (20A) as the organoclay filler were prepared by melt-compounding, solution-blending and static annealing of polymer/clay powder mixtures. The dependence of their structure and morphology on the preparation conditions was studied by X-ray diffraction (XRD and SAXS), polarized optical microscopy (POM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was shown that intercalated nanocomposites based on HDPE or HDMA cannot be obtained by solution-blending, as long as solvent removal is made at room temperature. In fact, wide angle XRD patterns of solution blended composites are similar to those of mechanical blends of clay and polymer. However, as demonstrated by XRD and SAXS, fast intercalation or even complete delamination was obtained when the HDMA composites prepared from solution were annealed statically at temperatures higher than the polymer melting point. This implies that solution-blending causes efficient fragmentation of the clay agglomerates into thin tactoids (though unintercalated) homogeneously dispersed in the polymer matrix. This conclusion, supported by the finding that annealing mechanical blends of polymer and clay powders only leads to intercalated structures, was confirmed by TEM and SEM analyses. Morphology investigation revealed that, in contrast to melt-compounding, solution-blending followed by static annealing fails to produce significant orientation of clay platelets and polymer crystallites. However, repeated compression molding cycles were shown by XRD and SAXS to cause increasing levels of orientation of the platelets and the polymer matrix parallel to the sample flat surface.