Polyethylene-octene Elastomer Research Articles

Exploring the Impact of Visual Heat Conduction Paths on Thermal Conductivity of Polymer Composites and the Practical Applications.

The theory of heat conduction paths has been widely recognized and widely studied in the research about the thermal conductivity of thermal conductive polymer composites at present. Encapsulating polymer pellets with thermally conductive fillers and processing them into thermally conductive polymer composites is a simple and effective method for constructing heat conduction paths. It is meaningful to investigate the related heat conduction mechanism of this method. Otherwise, this approach can significantly preserve the performance of the polymer substrate, making it highly valuable for practical material applications. In this work, polyethylene-octene elastomer (POE) pellets were encapsulated with thermal conductive fillers by physical absorption. Subsequently, the composite films containing heat conduction paths were fabricated using the encapsulated POE pellets through a heating press. Alumina (Al2O3), boron nitride (BN), and alumina/boron nitride hybrid (Al2O3/BN) fillers were used to prepare Al2O3@POE, BN@POE, and BN/Al2O3@POE composite films to investigate the influence of filler shapes on heat conduction path construction. The influence of the constitute and density of heat conduction paths on the thermal conductivity of composite films was analyzed by infrared thermal imaging, finite element analysis, and thermal resistance theory in detail. Owing to the reserved good adhesion and flexibility of the POE substrate, the composite films could be directly used as thermal interface materials for chip cooling, which presented a good heat dissipation effect. Furthermore, a series of integrated composite materials were prepared by the combination of encapsulated pellets with various functional films (copper foil, aluminum foil, and graphite sheet) through a one-pot heating press, exhibiting a good electromagnetic shielding effect. The performance of the composites and the corresponding preparation method demonstrate the strong significance of this research for practical applications.

Preparation and microcellular foaming of crosslinked polyethylene-octene elastomer by ionic modification

Polyethylene-octene elastomer (POE) has the advantages associated with thermoplastics and rubbers, and is therefore widely used in various fields. To achieve better performance, zinc oxide (ZnO) and stearic acid were introduced into maleic anhydride-grafted POE to create ionically crosslinked structures. Owing to these crosslinked structures, the tensile strength and creep resistance of POE were improved. After crosslinking, the viscoelastic properties of the polymer matrix were enhanced, thus stabilizing the cellular structure of the foams prepared by supercritical CO2 foaming. When the foaming condition was 8 MPa and 55 °C, the cell size of the POE-10ZnO foam was reduced from 50 µm to 23 µm, and the cell density was improved by approximately an order of magnitude higher than that of neat POE foam. The cyclic resilience of the foams was also investigated. The results showed that the POE-10ZnO foam exhibited good rebound resilience and high compressive strength.

Design and engineering of sustainable biocomposites from ocean-recycled polypropylene-based polyolefins reinforced with almond shell and hull

In this work, we discuss the development of a bio-based polypropylene composite by using recycled polypropylene (rPP) and almond shell with hull as green phases. In the first step, a blend of rPP and virgin PP (vPP) was manufactured and evaluated. The melt flow index (MFI) of the blend was higher (∼20 g/10 min) as compared to the neat rPP (∼3 g/10 min). With the introduction of polyethylene-octene elastomer (POE), the impact properties improved dramatically from 29.5 J/m to 203 J/m while the MFI remained close to ∼20 g/10 min which is ideal for injection molding applications. A finely ground almond shell powder was introduced to produce the composites at 20 wt.% filler content. The particle-matrix interface was clearly improved by the addition of 3% maleic anhydride grafted polypropylene (MA-g-PP), as observed in the SEM images. The good particle-matrix interfacial adhesion also improved the tensile and impact strengths by 17% and 15%, respectively. Results obtained in these experiments prove that recycled PP-almond shell reinforced composites show promise for the preparation of alternative new green materials to those manufactured with 100% non-upcycled materials.

Fabrication strategy for long‐chain branched polypropylene foams with high resilience and compressive strength

AbstractA flexible and controllable is proposed for fabricating long‐chain branched polypropylene (LCBPP) foams with high resilience and strength. LCBPP was blended with thermoplastic polyester elastomer (TPEE) using polyethylene octene elastomer grafted glycidyl methacrylate (POE‐g‐GMA) as a compatibilizer at different mass ratios, and the blends were then used to prepare foams at different temperatures by the supercritical CO2 batch foaming method. The foams were then tested for their compressive permanent strain and compressive strength. The results showed that introducing TPEE and POE‐g‐GMA increased the resilience. In particular, the permanent strain of the LCBPP/TPEE/POE‐g‐GMA foam at a ratio of 90/10/7 decreased from an initial 14.5% for the original LCBPP foam to 5% after five compression cycles. However, the compressive strength decreased from 65.59 to 39.82 kPa. Therefore, the foam density (ρ) and cell size (d) were adjusted to balance the resilience and strength. Increasing ρ/d from 0.32 to 3.10 increased the compressive strength significantly from 39.82 to 91.67 kPa while the permanent strain only increased 3.5%. Thus, the proposed strategy realized LCBPP foams with high resilience and compressive strength.

Effect of compatibilization agents and rice husk on the energy demand on the extrusion of recycled high-density polyethylene composites

The new trend of the circular economy encourages the preservation of the planet’s resources. In this sense, plastic recycling is one of the critical strategies in line with the circular economy. Rice husk is one of the principal agro-industrial waste in Ecuador. Its harnessing also promotes this trend. The energy demand in single screw extrusion has been studied to optimize production cost in extrusion process manufacturing. This study examined rice husk’s effect on the extrusion process’s energy demand using a recycled high-density polyethylene (rHDPE) with a tapered compression screw with dispersive and distributive mixers. Rice husk was reduced to a maximum particle size of 45μm. Two commercial compatibilizers based on Maleic anhydride-grafted polyethylene-octene elastomer (POE-g-MA) and ethylene-glycidyl methacrylate copolymer (E-g-MA) were used to enhance compatibility between the rice husk and the polymer matrix. The energy consumption was measured on the total energy of the extruder machine. The energy consumption (EC) and specific energy consumption (SEC) were measured to contrast the effect of the rice husk (3 wt%) and the addition of the compatibilizers. The SEC of RH/E-g-MA and RH/ POE-g-MA were at about 41.11% and 55.32%, respectively, lower than rHDPE. This work suggests that rHDPE/RH bio-composite processing incurs minor costs when coupling agents, processing conditions, and screws are carefully selected.

Structure and Properties of Recycled Polyester-cotton Blended Fiber/HDPE Composite Board

Recycled polyester-cotton blended fiber/high density polyethylene (HDPE) composite boards were prepared by internal mixing and compression molding two-step process with maleic anhydride grafted ethylene polyethylene-octene elastomer (POE-g-MAH) as compatibilizer. Two kinds of recycled polyester-cotton blended fiber were used as reinforcing fibers, including polyester-cotton long fiber (F1) and polyester-cotton short fiber (F2). Microstructure and properties of the composite boards reinforced with F1 and F2 were characterized by SEM and electronic universal tensile testing machine. The results showed that the comprehensive mechanical properties of polyester-cotton blended long fiber composite boards (F1HC4) and polyester-cotton blended short fiber composite boards (F2HC4) were optimal with a compatibilizer content of 4%. F1 had a significant effect on the mechanical properties of the composite boards in two kinds of fiber with the same addition of compatibilizer. The tensile strength, flexural strength, impact strength and of F1HC4 were 56.4%, 36.4% and 87.5% higher than that of F2HC4, respectively.

Preparation and characterization of wood-plastic composite by utilizing a hybrid compatibilizer system

The challenge to improve the interface in wood-plastic composite (WPC) has continued to remain a major setback in the field of wood technology. In this work, a novel hybrid compatibilizer system was developed. Chinese fir (Cunninghamia lanceolata) waste and low-density polyethylene were used as a reinforcing lignocellulosic material and matrix, respectively. Maleic anhydride grafted polyethylene octene elastomer (MPOE), octadecyl organically modified montmorillonite (OMMT) and their combinations were used as compatibilizers. The as-produced composites were characterized for their mechanical and physical properties using the SEM, FTIR, and mechanical testing. The result shows a significant increase in tensile strength of about 41.46 % when a mixture of MPOE and OMMT were used as compatibilizers. Moreover, the addition of MPOE led to the improvement of the impact strength by 26.89 %. Thus, the utilization of both compatibilizers offers an efficient route to improve the interaction and mechanical properties of WPC.

Structure, physical properties, and flame retardancy of POE/NR/EG blend foams: Effect of crosslinking

Elastomeric foams were produced by melt-mixing of polyethylene-octene elastomer (POE), natural rubber (NR), and expandable graphite (EG) in an internal mixer. The blend was later foamed by compression-molding method. EG was used as a filler to enhance flame retardancy of the blend foams. Dicumyl peroxide (DCP) was used as curative to crosslink the blend foams. The influence of DCP content (0.5, 0.7, 0.9, and 1.0 part(s) by weight, pbw) on rheological properties, structure, density, mechanical properties, thermal conductivity, and flame retardancy of the POE/NR/EG blend foams was investigated. The rheological analysis showed that the melt strength/viscosity of the POE/NR/EG blend foams increased with more DCP addition due to promoted crosslinking in the blend foams. The cellular structural observation by SEM technique revealed that the POE/NR/EG blend foams had close-cell structure. Increasing DCP content, the blend foams had smaller cell and narrower cell size distribution. The degree of porosity, however, was highest for the foamed blends added with 0.7 pbw DCP, which brought about the lowest thermal conductivity. Furthermore, it was found that the density, tensile strength, elastomeric recovery, and compressive strength increased with increasing content of DCP, but the elongation at break decreased. The POE/NR/EG blend foams reached the horizontal burning level of HF-1, and their oxygen index increased in accordance with an increase of DCP content. The results indicated that an appropriate use of DCP was critical for the crosslinked POE/NR/EG blend foams with optimum cellular structure, providing the best improvement in thermal insulation properties and good flame retardancy.

Foaming and Physical Properties, Flame Retardancy, and Combustibility of Polyethylene Octene Foams Modified by Natural Rubber and Expandable Graphite

Flame‐retardant blends of polyethylene‐octene elastomer (POE) and natural rubber (NR) filled with expandable graphite (EG) were melt‐mixed with azodicarbonamide to prepare elastomeric foams. The effect of the NR incorporation on the properties of EG filled POE foam was investigated. Gel content and microstructure observations revealed that the addition of NR into the POE/EG blend induced change in molecular structure, which produced a finer cellular structure during foaming. The compressive strength and elastomeric recovery of the POE/NR/EG blend foams were found to increase with increasing NR content. Based on the limiting oxygen index and horizontal burning measurements, all the POE/NR/EG blend foams were found to have good flame‐retardant properties. On the other hand, these POE/NR/EG blend foams exhibited higher combustion rates with an increasing NR content under high heat radiation and temperature in a cone calorimeter test. This study demonstrates that the combined use of NR as a modifier and EG as a flame retardant in POE foams provides an effective and practical method of obtaining well‐balanced improvements in cellular structure, mechanical properties, and flame resistance.

A new approach for silane curing polyolefin elastomer/linear low density polyethylene blends by Monosil and Sioplas processes

Silane cross-linking of metallocene-based polyethylene-octene elastomer (POE)/linear low density polyethylene (LLDPE) blend was carried out using the single-step Monosil process and two-step Sioplas process in an industrial scale twin-screw extruder. The study revealed that benzoyl peroxide (BPO) is a better initiator than dicumyl peroxide (DCP) for grafting reaction of vinyl trimethoxysilane (VTMS). The optimum values of compression set, gel content and tear strength which were, respectively, found to be 40.4%, 79% and 22.6% obtained at 0.2 w% of BPO. Addition of 0.3 w% antioxidant cause the curing time decreased from 14 to 16 h to 8 h. Oit of the sample was increased linearly with increasing the antioxidant content up to 0.5 w%. The effect of dibutyltin dilaurate (DBTDL) as catalyst on the melt flow index (MFI) of the silane grafted compounds, with the aim of selecting an appropriate silane grafting process, was investigated. The results showed a MFI= 6.4 g/10 min for the silane grafted compound obtained from the Sioplas process, but, MFI= 1.9 g/10 min which was due to the presence of the catalyst in the Monosil process indicated that this method is not a promising process for silane grafting.HighlightsSilane crosslinking POE/LLDPE blend was carried out using the Monosil and Sioplas processes in a twin-screw extruder.BPO is better initiator for grafting reaction of VTMS than DCP.The curing time required for confirming hot set test was decreased from 14 to 16 h to 8 h by addition of 0.3 wt% antioxidant, Irganox 1010.OIT time increased linearly with increasing the antioxidant concentration.Sioplas process caused lower crosslinking degree as well as minimum pre-crosslinking, which prevented the formation of gell spots and rough surface.

Strategy for the preparation of lightweight polypropylene/polyethylene‐octene elastomer composite foams with different phase morphologies using supercritical carbon dioxide

ABSTRACTPolypropylene (PP)/polyethylene‐octene elastomer (POE) composites with a “sea‐island” structure and a cocontinuous structure were prepared. With the selection of a suitable foaming temperature, the supercritical carbon dioxide foaming of PP/POE composites with different phase morphologies occurred only in the POE phase. The effects of the POE content, foaming temperature, pressure, and number of layers on the cell size, cell density, apparent density, foaming layer density, and foaming ratio under different phase morphologies were investigated by scanning electron microscopy, polarized optical microscopy, differential scanning calorimetry, and dynamic thermomechanical analysis. This article provides a novel approach for foaming PP at a low temperature. For PP/POE‐blended composites with a “sea‐island” structure, the foaming temperature is as low as 80 °C, and for PP/POE alternating multilayered composites with a cocontinuous structure, foaming can occur at 40 °C. Compared with the conventional methods for foaming PP, this method avoids the problems of a high foaming temperature, a narrow range of the foaming temperature, and a low melt strength of the PP. Thus, the PP foaming method was successfully improved, yielding a new technique for the preparation of lightweight PP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48157.

Modes of action of a mono-component intumescent flame retardant MAPP in polyethylene-octene elastomer

A mono-component intumescent flame retardant named ethylenediamine-modified ammonium polyphosphate (MAPP) is used in polyethylene-octene elastomer (POE). Insight into the flame-retardant mechanisms of the MAPP is provided from a new perspective. The fire performance of POE/MAPP composites is investigated by oxygen index (OI) and vertical burning (UL-94) tests. POE composite containing 35 wt% MAPP achieves a V-0 rating, and its OI is 29.3 vol%. The thermogravimetric analysis (TGA) and Fourier transform infrared spectra (FTIR) confirm that the incorporation of ethylenediamine changes the thermal decomposition of APP, mainly resulting in the formation of char layer with a thermally stable structure. Cone calorimeter analysis revealed the flame-retardant modes of action of MAPP in POE under forced-flaming conditions. Quantitative analysis illustrates that both the residue due to charring and the fuel dilution/flame inhibition resulting from the release of incombustible products/phosphorus species decrease the total heat release (fire load) by 20–28%. The residue increases linearly with increasing MAPP content, whereas the reduction in effective heat of combustion levels off. Moreover, the flame-retardant effect resulting from the protective properties of the char is discovered to be the dominant mode of action (up to 85% reduction) with respect to the peak heat release rate, leading to the excellent flame retardancy of POE/MAPP.

Synthesis of a novel reactive compatibilizer with large surface area and the application in monomer casting nylon/polyethylene–octene elastomer blends

Graphene oxide (GO) can be used as surfactants in numerous technological fields. For this study, functionalized GO was used as a novel reactive compatibilizer with large surface area to compatibilize immiscible polymer blends. The compatibilizer is composed of three parts with non-polar polymer chain, polar segment and GO sheet, which appears to be of more practical significance and can greatly expand the compatibilizing range. Monomer casting nylon (MC nylon)/polyethylene–octene elastomer (POE) was chosen as the immiscible polymer pairs to investigate the compatibility and comprehensive properties of the compatibilizer. With the incorporation of the novel reactive compatibilizer (GO-TEPAF-POE), the immiscible blends exhibited better compatibility and the dispersion of the minor phase (POE) is remarkably improved without obvious agglomerates. Moreover, GO-TEPAF-POE also acts as multifunctional fillers for MC nylon/POE blends, thus enhancing their mechanical properties and thermal stability. In particular, the notched impact strength values sharply increase by 84 % as opposed to the neat MC nylon. The novel compatibilizer with large surface area may broaden its potential application and fully exploits the extraordinary properties of these appealing carbon nanomaterials.

Cellular structure control and sound absorption of polyolefin microlayer sheets

In this work, a novel microlayer foam/film sheet with alternating soft/soft layers was successfully made via the microlayer co-extrusion technology. A blend of linear low density polyethylene (LLDPE) with poly (ethylene-octene) elastomer (POE) and foamed POE were used as the film and foam layers, respectively. Cross-linked POE showed enhanced melt strength, enabling well-defined cellular structure in the foam layers of the microlayer structure. Meanwhile, this technique provides a new mean to obtain polyolefin foaming material with excellent sound absorption characteristics. In select wavelengths, the sound absorption coefficient of the microlayer foam/film structure improved 2–3 times compared with conventional single-layer materials. In addition, the mechanical properties of the foam/film sheets were also improved markedly through the multilayer assembly of foam/film layers at the micron scale.

Supramolecular hydrogen-bonded polyolefin elastomer/modified graphene nanocomposites with near infrared responsive shape memory and healing properties

Small amounts (0.25–1wt%) of octadecylamine modified graphene oxide (ODA-GO) were incorporated into a 3-amio-1,2,4-triazole (ATA) crosslinked maleated polyethylene-octene elastomer (ATA-POE), a structurally dynamic supramolecular hydrogen-bonded thermoplastic elastomer, via melt blending to prepare ATA-POE/ODA-GO nanocomposites. Field-emission scanning electron microscopy and X-ray diffraction analysis for the ATA-POE/ODA-GO composites revealed that the ODA-GO sheets were dispersed at the nanoscale level in the elastomer matrix which results in enhancement of the mechanical properties of the nanocomposites at low filler loadings. These nanocomposites exhibit both shape memory and scratch-healing effects under near infrared (NIR) light exposure. It was revealed from the results that ODA-GO acted as NIR-triggered nanoheaters as well as reinforcing filler for the elastomer matrix.

Improving viscoelasticity and rebound resilience of crosslinked low-density polyethylene foam by blending with ethylene vinyl acetate and polyethylene-octene elastomer

To obtain high-rebound resilience of crosslinking low-density polyethylene (LDPE) foam and decrease the foam density at the same content of foaming agent, the melt viscoelasticity of LDPE with different compositions (ethylene vinyl acetate [EVA], polyethylene-octene elastomer, and crosslinking agent) was investigated by dynamic rheology test. Then, LDPE/EVA/(polyethylene-octene elastomer) foams with different composition ratios were produced by a continuous foaming process and investigated by the rebound resilience test. The results show that the melt viscoelasticity behavior of LDPE and its blends in the molten state possessed more melt elasticity behavior after the crosslinking was introduced. Meanwhile, the rebound resilience of LDPE foam was increased 54% at the lower foam density (0.031 g/cm3). It could meet the requirements of sports mats for high-rebound resilience (>50%) and decrease the material cost when EVA was introduced into the foaming system. J. VINYL ADDIT. TECHNOL., 22:61–71, 2016. © 2014 Society of Plastics Engineers

Wood-Plastic Composites Prepared by Waste Polypropylene and Toughening

The feasibility of wood-plastic composite (WPC) and efficiency of impact strength improvement by toughening agents were discussed using waste polypropylene (PP) from e-wastes as experimental materials. The researching results indicated that it could be used in manufacturing wood-plastic composite while the impact strength of waste PP decreased by 47.3% comparing with new PP. Adding polyethylene octene elastomer (POE) and styrene-butadiene-styrene (SBS) could effectively enhance the impact strength of WPC. When adding 15% of POE and SBS individually, the impact strength increased by 113.2% and 43.4%. The modulus of rupture (MOR) and modulus of elasticity (MOE) lowered when toughening agents were added, which should be made into consideration in practical application according to the property of materials comprehensively.

Rheological and morphological behaviors of polyamide 6/acrylonitrile–butadiene–styrene/nanoclay nanocomposites

In this study, the effect of nanoclay on the rheological and morphological properties of polyamide 6 (PA6)/acrylonitrile–butadiene–styrene (ABS) blends was investigated. The scanning electron microscopy micrographs showed that with increment in the nanoclay content, the dispersed phase droplets size and their polydispersity index decreased, and the finer and more uniform dispersed phase was obtained. The transmission electron microscopy micrographs of nanocomposites indicated well-dispersed nanoclay tactoids in the polymer matrix produced by exfoliation of the nanoclay in the polymeric blends. Dynamic strain sweep experiments showed that the extent of the linear viscoelastic region is sensitive to the nanoclay content and compatibilizer. With increasing nanoclay content in the blend, the extent of the linear viscoelastic region decreased. On the other hand, the rheological measurements revealed that the nanoclay content has a significant effect on the moduli and complex viscosity of the blends. These results have indicated that with increasing nanoclay content the storage modulus ( G′), loss modulus ( G′′) and complex viscosity ( η*) increased. In addition, the results of creep experiments revealed that with the addition of compatibilizer (polyethylene octene elastomer grafted with maleic anhydride) and nanoclay to PA6/ABS blends, creep and recovery strain, over time, decreased remarkably and the recovery percentage increased. It was concluded that there is a good conformity between the results obtained from morphological and rheological investigations.

Deformation reversibility enhancement of thermoplastic vulcanizates based on high density polyethylene and ethylene–propylene–diene terpolymer

Thermoplastic vulcanizates (TPVs) based on high density polyethylene (HDPE)/ethylene–propylene diene copolymer (EPDM) blends with different compositions of polyethylene–octene elastomer (POE) were prepared by dynamic vulcanization, the effects of the POE incorporation on deformation reversibility enhancement, mechanical, dynamic mechanical and morphological properties of the TPVs were investigated systematically. Characterization via FE-SEM confirms the tearing strips on the fracture surface of HDPE/EPDM TPVs were formed by the residual plastic deformation of HDPE lamellae crystals, which also resulted in the relatively high permanent deformation of TPVs. The elasticity of TPV matrix was improved greatly by the incorporation of POE and the tension set was decreased obviously. RPA results show that the increasing frequency led to the increased elastic modulus while the incorporation of POE in matrix led to the decreased elastic modulus. The tan δ decreased continuously with the increasing frequency and the incorporation of POE had a non-ignorable influence on the tan δ of HDPE/EPDM TPVs.

Preparation and properties of polyethylene-octene elastomer (POE)/organoclay nanocomposites

Polyethylene-octene elastomer/organoclay nanocomposites were prepared by a melt blending process. It was found that the addition of a small amount of glycidyl methacrylate and a peroxide during the melt mixing induced facile intercalation of the polymer chains into the organoclay and dispersion of the clay particles on the nanometer scale, which was confirmed by X-ray diffraction and transmission electron microscopy. Enhanced mechanical properties of the nanocomposites were observed from tensile, dynamic mechanical, and tear testing. Oscillatory shear-controlled rheology in the molten state of the nanocomposites revealed a pseudo solid-like behavior as well as an enhanced shear thinning behavior.