• Fibers and Polymers
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• v.4 no.4
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• pp.195-198
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• 2003

Epoxidized polybutadiene (EPB) was prepared by polybutadiene (PB) with m-chloroperbenzoic acid (MCPBA) in homogeneous solution. EPB was blended with poly(3-hydroxybutyrate) (PHB) up to 30 wt% by solution-precipitation procedure. The thermal decomposition of PHB/EPB blends was studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and differential thermal analysis (DTA). The thermograms of PHB/EPB blends contained a two-step degradation process, while that of pure PHB sample exhibited only one-step degradation process. This degradation behavior of PHB/EPB blends, which have a higher thermal stability as measured by maximum decomposition temperature and residual weight, is probably due to crosslinking reactions of the epoxide groups in the EPB component with the carboxyl chain ends of PHB fragments during the degradation process, and the occurrence of such reactions can be assigned to the exothermic peaks in their DTA thermograms.

• Fibers and Polymers
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• v.3 no.3
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• pp.109-112
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• 2002

Polybutadiene(PB) was epoxidized to various extents with m-chloroperbenzoic acid (MCPBA) in homogeneous solution. The thermal properties of the epoxidized PBs were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). As a result of epoxidation the glass transition temperature (Tg) of PB increased by approximately $0.8^{\circ}$ for each 1 mol% of epoxidation. The thermal decomposition of the epoxidised PBs occurred in two-step process, while that of PB exhibited apparent one-step degradation process.

• Elastomers and Composites
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• v.47 no.1
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• pp.30-35
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• 2012

Novel bio-polybutadiene polymers with controlled molecular weight (MW), MW distribution, chemical composition and micro structure were synthesized by a living anionic polymerization of butadiene and the subsequent coupling reaction of the thus obtained living polybutadiene and a vegetable oil. Anionic polymerization of butadiene was carried out in THF solvent using n-BuLi initiator. The resulting living polybutadienyllithium polymer was then reacted with epoxidized soybean oil (ESO) to obtain a star-polymer of polybutadiene and vegitable oil. Three different bio-elastomers were prepared by coupling living polybutadienes of MWs 1000, 5000 and 1000g/mol with ESO. The molecular structure and MW of the polybutadienes and bioelastomers were characterized by $^1H$-NMR, FTIR and GPC techniques.

• Polymer(Korea)
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• v.33 no.6
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• pp.608-614
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• 2009

The cation-exchange membrane which was sulfonated styrene-ethylene/buthlene-styrene(SEBS) block copolymer containing the high impact polystyrene (HIPS) was prepared via post-sulfonation and casting method using the epoxidized polybutadiene and divinylbenzene as crosslinking agents. Post-sulfonation was carried out with sulfuric acid as sulfonating agent and silver sulfate as initiator in the nitrogen atmosphere. The basic properties of membranes, degree of sulfonation (DS), water uptake, ion-exchange capacity (IEC), electrical resistance, and modulus have been examined. DS of membrane increased with increasing the sulfonation time. The maximum DS of membrane containing 10 wt% HIPS was 83.6 %. The water uptake and IEC of membranes gradually increased as increasing the DS. The maximum water uptake and IEC of membranes were 43.8 % and 1.14 meq/g, respectively. The lowest electrical resistance of membrane containing the 20 wt% HIPS was $83\;\Omega{\cdot}cm^2$. The electrical conductivity of membrane containing 10 wt% HIPS was $1.22\times10^{-4}S/cm$. The modulus of membrane increased with increasing DS and these values were 153 and $204\;kgf/cm^2$ before and after sulfonation, respectively.

• Elastomers and Composites
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• v.56 no.3
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• pp.179-186
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• 2021

Carbon-based nanofillers, including nanodiamond (ND) and carbon nanotubes (CNTs), have been employed in epoxy matrixes for improving the toughness, using the tow prepreg method, of epoxy compounds for high pressure tanks. The reinforcing performance was compared with those of commercially available toughening fillers, including carboxyl-terminated butadiene acrylonitrile (CTBN) and block copolymers, such as poly(methyl methacrylate)-b-poly(butyl acrylate)-b-poly(methyl methacrylate) (BA-b-MMA). CTNB improved the mechanical performance at a relatively high filler loading of ~5 phr. Nanosized BA-b-MMA showed improved performance at a lower filler loading of ~2 phr. However, the mechanical properties deteriorated at a higher loading of ~5 phr because of the formation of larger aggregates. ND showed no significant improvement in mechanical properties because of aggregate formation. In contrast, surface-treated ND with epoxidized hydroxyl-terminated polybutadiene considerably improved the mechanical properties, notably the impact strength, because of more uniform dispersion of particles in the epoxy matrix. CNTs noticeably improved the flexural strength and impact strength at a filler loading of 0.5 phr. However, the improvements were lost with further addition of fillers because of CNT aggregation.