• Elastomers and Composites
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• v.48 no.4
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• pp.276-281
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• 2013

Polyester type polyurethane foam modified with acrylic polyol was prepared by quasi prepolymer method. Thermal and dynamic mechanical properties of polyurethane foam were analysed by thermal gravimetric analysis(TGA) and dynamic mechanical analysis(DMA). Also, glass transition temperature was measured by differential scanning calorimeter(DSC). As acrylic polyol contents were increased, thermal stability measured by TGA was slightly decreased. Storage modulus was increased and tan delta was decreased with increasing of acrylic polyol contents.

• Elastomers and Composites
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• v.48 no.3
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• pp.241-248
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• 2013

Polyester type polyurethane foam has low hydrolysis resistance. It was overcome with addition of acrylic polyol by quasi prepolymer method. Tensile strength and hardness of polyurethane foam contained acrylic polyol was increased with increasing of acrylic polyol contents. But split tear strength and tear strength was slightly changed. Hydrolysis resistance of polyurethane foam was measured by loss % of tensile strength. It was improved with increasing of acrylic polyol contents from 25.5g to 102g.

• Elastomers and Composites
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• v.34 no.4
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• pp.299-314
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• 1999

Bonding metal and textile components to rubber has always posed a problem. In this paper, an attempt had been made to modify textile and metal surfaces for bonding with rubber. The metal surfaces were modified using silane coupling agents and textile fibers were modified using plasma polymerization techniques. Some results on adhesion of metals to a range of sulfur-cured rubber compounds using a combination of organofunctional silanes are given here. The treatment was not only effective for high-sulfur compounds but also for low-sulfur com pounds as used in engine mounts and even for some semi-EV compounds. Coatings of plasmapolymerized pyrrole or acetylene were deposited on aramid and polyester tire cords. Standard pull-out force adhesion measurements were used to determine adhesion of tire cords to rubber compounds. The plasma coatings were characterized by various techniques and the performance results are explained in an interpenetrating network model.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.55-58
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• 2004

Phenolin resin, prepared form phenol and formaldehyde, is one of the oldest thermosetting resins available. Phenolic resins are cured via condensation polymerization with evolution of water, which in molding process is a big problem. The use of phenolic resins in glass fiber composites is growing, primarily due to their low flame spread, low smoke generation and low smoke toxicity properties. SMC of phenolics has been rearched since the 1986. The technology challenge was to match resin viscosity, handling and cure with those for the polyester SMC to avoid any special processing for fabricators and end users. Phenolic SMC was chosen because of the ease of molding to the required shape with light- weight, thin wall structure and with excellent fire protection.

• Advances in concrete construction
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• v.5 no.4
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• pp.331-343
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• 2017

In this study a polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with natural Alfa fibers has been studied. The results of flexural testing of unreinforced polymer concrete with different rates of charges (marble) showed that the concrete with 20% of marble is stronger and more rigid compared to other grades. Hence, a rate of 20% of marble powder is selected as the optimal value in the development of polymer concrete reinforced Alfa fibers. The fracture results of reinforced polymer concrete with 1 and 2 wt% of chopped untreated or treated Alfa fibers showed that treated Alfa (5% NaOH) fiber reinforced polymer concrete has higher fracture properties than other composites. We believe that this type of concrete provides a very promising alternative for the building industry seeking to achieve the objectives of sustainable development.

• Elastomers and Composites
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• v.54 no.4
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• pp.279-285
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• 2019

Bio-based polyester polyols were synthesized using esterification with azelaic acid, sebacic acid, and 1,3-propanediol. Polyurethanes were prepared using chain extenders (1,4-Butanediol, 1,3-Propanediol, and isosorbide) and 4,4'-diphenylmethane diisocyanate with a mixing ratio of 1:1:1.1. Subsequently, the properties of the polymers prepared using the different chain extenders were compared. The synthesis of polyurethane was confirmed by FT-IR, TGA, and GPC. The mechanical properties (hardness, ball rebound, and tensile strength) of the materials were analyzed using shore A tester, taber abrasion, and UTM. heat, chemical, and water resistances of the prepared materials were measured by comparing the tensile strengths according to external changes.

• Transactions on Electrical and Electronic Materials
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• v.18 no.4
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• pp.203-206
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• 2017

The effect of the content of microsilica and nanosilica continuously modified with hydroxy silane and epoxy-modified silicone in cycloaliphatic epoxy/microsilica/nanosilica composites (EMNCs) on the mechanical and water repellent properties was evaluated. Surface-modified micro- and nanosilica was well-mixed with a cycloaliphatic epoxy resin in the presence of polyester-modified polydimethylsiloxane (PEM-PDMS) as a dispersing agent using an ultrasonicator. Tensile and flexural tests were carried out using a universal testing machine (UTM). The water repellent property was evaluated by contact angle measurements of water on the composite surface. Tensile strength of the composite could be enhanced by 32.2% up to 91.4 MPa, and the flexural strength was raised to 122.0 MPa, which is 38.8% higher than that of neat epoxy. The contact angle of water on the composite was as high as $104.1^{\circ}$.

• Composites Research
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• v.26 no.4
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• pp.265-272
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• 2013

Fiber-reinforced plastic (FRP) is applied to fabricate the main structures of composite boats. Most of them are made from molds. These products deform after releasing from the mold and they also deform in high temperature environment. Therefore, experimental investigation and evaluation of deformation of laminated composite structures under various manufacturing and working conditions are necessary. The specimens of L-shape and curveshape were made from unsaturated polyester resin and fiberglass material. Input factors (independent variables) are percentage of hardener and manufacturing temperature and four levels of working temperature and output factor is the deformation which is measured on these specimens. From the results, it was observed that the higher the hardener rate and temperature, the lower the deformation. When the working temperature increased, the specimens showed great variations for the initial deformation values. Besides, the values of deformation or input factors could be predicted by regression equations.

• Membrane Journal
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• v.16 no.2
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• pp.85-105
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• 2006

Poly(lactic acid) is a linear aliphatic thermoplastic polyester, produced by the ring-opening polymerization of lactides and the lactic acid monomers, which are obtained from the fermentation of sugar feed stocks, corn, etc. PLA has high mechanical, thermal plasticity, fabric-ability, and biocompatibility, So PLA is a promising polymer far various end-use applications. In recent time, the intercalation of polymers from either solution or the melt in the silicate galleries of clay is the best technique to prepare nanocompoiste material which often exhibit remarkable improvement of mechanical, thermal, optical and physicochemical properties when compared with the pure polymer or conventional composites. Layered silicate is naturally abundant, economic, and more importantly benign to the environment.

• Composites Research
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• v.34 no.3
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• pp.148-154
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• 2021

Carbon/epoxy composite bipolar plate (BP) is a BP that is likely to replace existing graphite bipolar plate of vanadium redox flow cell (VRFB) due to its high mechanical properties and productivity. Multi-functional carbon/epoxy composite BP requires graphite coating or additional surface treatment to reduce interfacial contact resistance (ICR). However, the expanded graphite coating has the disadvantage of having low durability under VRFB operating conditions, and the surface treatments incur additional costs. In this work, an excessive resin absorption method is developed, which uniformly removes the resin rich area on the surface of the BP to expose carbon fibers by applying polyester fabric. This method not only reduces ICR by exposing carbon fibers to BP surfaces, but also forms a unique ditch pattern that can effectively hold carbon felt electrodes in place. The acidic environmental durability, mechanical properties, and gas permeability of the developed carbon/epoxy composite BP are experimentally verified.