• Elastomers and Composites
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• v.46 no.3
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• pp.204-210
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• 2011

In this study, Jute fibers reinforced polypropylene (JFRP) composites were manufactured by injection molding technique. In order to improve the affinity and adhesion between fibers and thermoplastic matrices during manufacturing, Maleic anhydride (MA) as a coupling agent have been employed. Untreated and treated surfaces of jute fibers were characterized using SEM and Fourier transform infrared (FTIR). Physical properties like water absorption rate were studied. Tensile and flexural tests were carried out to evaluate the composite mechanical properties. Tensile test and bending test indicated that JFRP composites show higher strength and modulus than pure PP. In addition, strength and modulus were found to be influenced by the variation of MAPP content (1%, 2%, and 3%). Tensile fracture surfaces were examined using scanning electron microscope. It ensures better interfacial adhesion between fibers and matrix by increasing the percentage of MAPP.

• Polymer(Korea)
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• v.38 no.3
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• pp.327-332
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• 2014

Polymer/wood flour composites are recently attracting a lot of interest because they are economic and ecofriendly. In this study, the effects of wood flour size on the thermal and mechanical properties of a polypropylene/wood flour composite were investigated. Mechanical properties of the composite samples prepared by melt-mixing and compression molding were tested by UTM and an izod impact tester, and thermal properties of them were measured by TGA, DMA, DSC and TMA. The best coupling agent was selected by testing three kinds of maleic anhydride modified polypropylene coupling agents, and under the same condition, the effects of wood flour size on the physical properties of the composite were investigated. According to the test results for four different wood flour sizes of 600, 250, 180 and $150{\mu}m$, flexural strength, flexural modulus, crystallinity and water-resistivity of the composite increased with decreasing wood flour size.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1136-1140
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• 1999

Melt blends of polymide 6(PA6) and polypropylene grafted maleic anhydride(PP-g-MA) were prepared to study the influence of chemical reaction between the two polymer components. The tensile, flexural, izod impact, dynamic mechanical properties and phase structure were investigated for this blend system. Tensile strength and modulus of the blends showed synergetic effect upon blending of two polymer components. Flexural properties maintained the value of numerical mean calculated from the weight ratio of two components. Also, notched izod impact strengths showed maximum in th PA6/PP-g-MA 50/50 wt % blend. From the change of tan ${\delta}$ observed, we confirmed the increase of miscibility in this blend system by chemical reaction between PA6 and PP-g-MA. Blends of good impact resistance could be obtained when the PP-g-MA particles of $2{\mu}m$ was dispersed in the PA6 matrix.

• Clean Technology
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• v.19 no.2
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• pp.140-147
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• 2013

In this study, chemical demulsification and electrical treatment methods were investigated for improving the efficiency of water separation from a water/bitumen emulsion. Two types of motor oils (GS Caltex, Deluxe Gold V 7.5 W/30 and, Hyundai gear oil 85 W/140) were used as model oils in basic experiments to investigate the effects of a demulsifier on water/oil emulsion separation. Chemical demulsifiers showing good water separation performance were then used in asphalt emulsion and bitumen emulsion separation trials. Maleic anhydride and e-caprolactam were shown to be good oil soluble demulsifiers and 2-ethylhexyl acrylate and acrylic acid were effective as water soluble demulsifiers. Based on the results obtained in basic experiments, these four demulsifiers were used in further asphalt emulsion experiments. The oil soluble demulsifiers showed higher water separation efficiencies than the water soluble demulsifiers. To investigate the water separation efficiency using a combined chemical and electrical treatment method, the water/bitumen emulsion was separated with the electrical oil treatment apparatus after a chemical demulsifier had been added to it.

• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1141-1146
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• 1999

Melt blend of PA6/PP-g-MA system containing SEBS-g-MA as a compatible impact modifier was prepared to investigate the change of mechanical properties and morphologies. The tensile strength slightly decreased, but the elongation at break increased with increasing content of SEBS-g-MA in the blend. Also the notched izod impact strength increased with increasing the content of PP-g-MA and SEBS-g-MA. It is attributed to improved compatibilization and interfacial adhesion by reaction of the amide of PA6 with maleic anhydride of SEBS-g-MA and PP-g-MA. The result of dynamic mechanical analysis(DMA) showed a typical behavior of the compatibilization in the polymer blends. Finally, in the phase structure observed by the use of SEM, we confirmed improvement of the compatibilization and interfacial adhesion with increasing the content of SEBS-g-MA and PP-g-MA.

• Polymer(Korea)
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• v.35 no.2
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• pp.124-129
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• 2011

Wood plastic composites (WPCs) are attracting a lot of interest recently. In this study, wood flour/polyethylene (PE) composites panels comprised of a coupling agent and nanoclay were prepared by melt-blending followed by compression molding. Five maleic anhydride grafted polyethylene (MAPE) coupling agents were tested, and the best choice and its optimum content were determined. The mechanical properties of the WPCs were measured by UTM, and the thermal properties were measured by TGA, DMA, DSC, and TMA. Adding just a small amount (1 phr) of organoclay made the tensile and flexural strength and the crystallinity of the WPC somewhat increase and the storage modulus and dimensional stability of the WPC largely increase. SEM images showed that the coupling agent drastically improved wood flour/PE interfacial bonding. Selecting the best coupling agent optimized content and adding a small amount of organoclay resulted in a high performance wood flour/PE composite.

• Polymer(Korea)
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• v.37 no.2
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• pp.204-210
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• 2013

Effects of additives (lubricant and antioxidant) and melt-blending condition (temperature, time and rotor speed) on the mechanical properties of polypropylene-based wood polymer composites (WPCs) were investigated. WPCs were prepared by melt-blending followed by compression molding. To understand melt-blending procedure, torque change of the WPC melt-blend was monitored. Maleic anhydride modified PP and nanoclay were used as a compatibilizer and a reinforcing filler, respectively. UTM and izod impact tester were used to measure the mechanical properties of the WPCs and a color-difference meter was used to measure the discoloration of the WPCs according to melt-blending condition. The mechanical properties showed that the optimized melt-blending condition was $170^{\circ}C$, 15 min, and 60 rpm. The mechanical properties of the WPCs decreased with increasing lubricant and antioxidant content. The two step method, adding wood flour later separately during melt-blending, was more effective than the typical one step method for improving the mechanical properties of the WPCs.

• Polymer(Korea)
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• v.28 no.2
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• pp.162-169
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• 2004

Poly[styrene-b-(ethylene-1-butene)-b-styrene] triblock copolymer (SEBS) was functionalized with 0 to 3.0 phr maleic anhydride and the amount of dicumyl peroxide used as an initiator was varied from 0 to 0.3phr. The gel content of the modified SEBS was determined by xylene extraction and poly(oxymethylene) was blended with the modified SEBS. The impact, tensile, flexural strength and morphologies of the blends were investigated. The Izod impact strength of poly(oxymethylene) was improved through its blending with modified SEBS. However, the Izod impact strength of poly(oxymethylene)/modified SEBS blend decreased above 5% modified SEBS content. Regarding the effect of dicumyl peroxide content on the Izod impact strength, the blend had a maximum Izod impact strength when poly(oxymethylene) was blended with modified SEBS prepared with 0.1 phr dicumyl peroxide. It was also confirmed by SEM micrographs that the average particle size of modified SEBS in poly(oxymethylene)/modified SEBS blends was smaller than that of SEBS in poly(oxymethylene)/SEBS blends.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.275-282
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• 2021

High-molecular-weight maleic anhydride-grafted polylactic acids (HMMA-g-PLA) compatibilizers were prepared by melt grafting in a twin screw extruder using di(tert-butyl-perxoyisopropyl)benzene (PK-14; as initiator), maleic anhydride (MA), and divinylbenzene (DVB). To determine the properties of the prepared HMMA-g-PLA compatibilizers, Fourier transform infrared (FTIR), Melt index (MI), and back-titration analyses were performed. On increasing DVB concentration, grafting yield of HMMA-g-PLA increased but MI decreased because 𝛽-scission of PLA was restrained by the DVB, and thus, the molecular weight of HMMA-g-PLA increased. PLA-based wood-plastic composites (WPCs) were prepared using HMMA-g-PLA by melt blending through a single screw extruder. The flexural and impact strengths of WPCs compatibilized with HMMA-g-PLA were greater than those of WPCs produced without HMMA-g-PLA. Scanning electron microscope (SEM) studies indicated that increased mechanical properties were caused by excellent interfacial adhesion between PLA and wood fibers due to the addition of HMMA-g-PLA. However, rather high contents of HMMA-g-PLA reduced the mechanical properties of WPCs. We believe that lower molecular-weight of HMMA-g-PLA added as an compatibilizer, compared with PLA polymer, caused the reduction of mechanical properties.

• Composites Research
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• v.37 no.3
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• pp.238-245
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• 2024

In this study, as part of the development of a monitoring system for the efficient maintenance of steel pipes, an experimental study was conducted to evaluate the performance of steel pipes treated with modified polyethylene coating. In the case of the conventional mechanical pre-coating method, there was a deterioration in polyethylene adhesion during expansion testing, which led to the application of a chemical pre-treatment process using a calcium-mixed phosphate zinc film to resolve this issue. SEM and EDX analyses showed that the densest structure was observed at a Zn/Ca ratio of 1.0, and improved heat resistance compared to the conventional method was confirmed. Additionally, to prevent coating detachment during expansion, an evaluation of adhesion and elongation was conducted on steel pipes with modified polyethylene coating, incorporating materials such as elastomers based on maleic anhydride grafting, metal oxides, blocking agents, and slip agents. Experimental results showed that the specimen (S4) containing all modified materials exhibited more than a 25% performance improvement compared to the specimen (S2) containing only metal oxides. Lastly, the development and performance evaluation of wedge-shaped socketing and pressing wheels, which are part of the pipe fixing accessories, were conducted to prevent surface coating damage on the completed pipes.