• Title, Summary, Keyword: polybutadiene

Search Result 76, Processing Time 0.029 seconds

Epoxidized Polybutadiene as a Thermal Stabilizer for Poly(3-hydroxybutyrate). II. Thermal Stabilization of Poly(3-hydroxybutyrate) by Epoxidized Polybutadiene

  • Choi, Ju-Yol;Lee, Jong-Keun;You, Young;Park, Won-Ho
    • Fibers and Polymers
    • /
    • v.4 no.4
    • /
    • pp.195-198
    • /
    • 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.

A study on the oxidation characteristics of Polybutadiene & Polyisoprene containing various types of antioxidants by DSC (산화방지제(酸化防止劑)를 배합(配合)한 Polybutadiene과 Polyisoprene의 DSC에 의(依)한 산화특성(酸化特性) 연구(硏究))

  • Yoo, Chong-Sun;Choi, Seoi-Young;Paik, Nam-Chul
    • Elastomers and Composites
    • /
    • v.18 no.4
    • /
    • pp.140-147
    • /
    • 1983
  • The purpose of this dissertation is to increase oxidation resistance for Polybutadiene & Polyisoprene, and to investigate the energetics of inhibited oxidation of Polybutadiene & Polyisoprene stabilized with various types of antioxidants using DSC. The results of the study are as fellows: 1. In the DSC SCREEN for the onset temperature of oxidation, Polybutadiene was faster than Polyisoprene for the samples containing no antioxidant in air. 2. In the DSC evaluation for Polybutadiene, Recipe BG-4 with 2.0phr compounds of antioxidant was the best effective, and Recipe BS-4 with 2.0phr compounds of antioxidant was the worst effective, and the degrees of effect of antioxidant were exhibited in the ranking of G-1, D, BHT, and SP, roughly. 3. In the DSC evaluation for the Polyisoprene, Recipe IG-4 with 2.0phr compounds of antioxidant was the best effective, and Recipe ID-4 with 2.0phr compounds of antioxidant was the worst effective, and the degrees of effect of antioxidant were exhibited in the ranking of G-1, SP, BHT, and D roughly. 4. In the study on enthalpy which depends on exothermal reaction, the enthalpy of Polyisoprene was gloater than that of Polybutadiene. However, the problem was not solved completely, and it needs further studies.

  • PDF

A Study on the Physical Properties and Adhesion Characteristics of Polyurethane Resin (폴리우레탄 수지의 물성 및 접착특성에 관한 연구)

  • Kim, Young-Joon;Chang, Ki-Young;Kim, Gu-Ni;Chun, Yong-Chul;Yoo, Chong-Sun;Park, Sang-Wook
    • Elastomers and Composites
    • /
    • v.31 no.2
    • /
    • pp.104-110
    • /
    • 1996
  • The polyurethane was synthesized by the reaction of polycaprolactone diol(Mw 2000), 4,4'-diphenylmethane diisocyanate and 1,4-butanediol as the chain extender. Also, the modified polyurethane polymers based on liquid polybutadiene as a part of soft segment and dimethylolpropionic acid as a chain extender, giving polyurethane with various polarity, were synthesized. The thermal, mechanical, adhesion properties and water contact angles of the polyurethanes were examined. From the result of the water contact angle, the polarity of the acid modified PU containing 6% acid content was unchanged but mechanical and adhesion properties were improved. The water contact angles on polybutadiene modified PU films were increased with increasing polybutadiene content. The mechanical properties of the polybutadiene modified PU were higher than that of acid modified PU. However, the mechanical properties were reduced as polybutadiene content increased. The result is presumably due to phase separation between hard segment and soft segment. The peel strength of the polyurethane introduced with 5wt% polybutadiene was improved about 150% than that of unmodified PU. The same as the mechanical properties, the more polybutadiene was introduced, the lower peel strength was obtained.

  • PDF

Studies on the Polymerization and Characterization of Carboxyl-Terminated Polybutadiene (Ⅰ). Effects of Initiator Concentration on Yields and various Characteristics (Carboxyl-Terminated Polybutadiene 의 중합 및 특성에 관한 연구 (제1보). 개시제농도가 수율 및 특성에 미치는 영향)

  • Jung-Bu Kang;Kyung-Joon You;Suk-Ky Kwon;Dong-Young Oh
    • Journal of the Korean Chemical Society
    • /
    • v.24 no.5
    • /
    • pp.398-403
    • /
    • 1980
  • Carboxyl-terminated polybutadiene was prepared by free-radical polymerization using 4,4'-azobis-[4-cyano valeric acid] as an initiator and the effect of initiator concentration on polymer properties was investigated. Polymerization of the carboxyl-terminated polybutadiene was carried out varying the initiator concentration reacting with a constant butadiene concentration. The carboxyl weight percent decreased with increasing initiator concentration. The conversion was proportional to the square root of initiator concentration, giving a functionality greater than 2.0 which is consistent with the general tendency of free radical polymerization.

  • PDF

Epoxidized Polybutadiene as a Thermal Stabilizer for Poly(3-hydroxybutyrate). 1. Effect of Epoxidation on the Thermal Properties of Polybutadiene

  • Park, Ju-Yol;Lee, Jong-Keun;Park, Won-Ho
    • Fibers and Polymers
    • /
    • v.3 no.3
    • /
    • pp.109-112
    • /
    • 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.

Synthesis and Characterization of Bio-Elastomer Based on Vegetable Oils (식물성 오일 기반 바이오 탄성체의 합성과 특성)

  • Lee, Hyeok;Kwak, Kyung-Hwan;Kim, Jin-Kuk
    • Elastomers and Composites
    • /
    • v.47 no.1
    • /
    • pp.30-35
    • /
    • 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.

Rheology and Curing of Hydroxyl Terminated Polybutadiene/(Sugar or Calcium Carbonate) Suspension (Hydroxyl Terminated Polybutadiene/(설탕 또는 탄산칼슘) 현탁계의 유변물성 및 경화특성)

  • Lee, Sangmook;Hong, In-Kwon;Lee, Jae Wook;Jeong, Won Bok
    • Polymer(Korea)
    • /
    • v.38 no.4
    • /
    • pp.417-424
    • /
    • 2014
  • Reactivity and rheological behavior of highly concentrated polymer bonded explosives (PBX) simulant was studied. As a binder, thermosetting hydroxyl terminated polybutadiene (HTPB) was used. By using bimodal $CaCO_3$ (size ratio 10:1) and sugar particles (size ratio 25:1) as fillers, maximum 75 v% filling was possible during melt mixing. The relative viscosities of bimodal suspension were much lower than those of unimodal one and showed minimum values at 0.25 of fine particle fraction. In curing experiment, as curing temperature increased, the time of initiation and completeness of curing reaction became shortened, the torque kept low, and the change of internal temperature decreased.

Gas Separation Membranes Prepared from Polystyrene-block-Polybutadiene/Poly(phenylene oxide) Blends for Carbon Dioxide Separation from a Flue Gas (배기가스로부터 이산화탄소 분리를 위한 SB 이종 블록공중합체/즐리페닐렌 옥사이드 블렌드 기체분리막)

  • Jung, You-Sun;Kim, Chang-Keun
    • Polymer(Korea)
    • /
    • v.32 no.6
    • /
    • pp.593-597
    • /
    • 2008
  • To separate carbon dioxide from a flue gas, membranes for gas separation was fabricated from polystyrene-b-polybutadiene (SB) diblock copolymer blends with poly(phenylene oxide), PPO. SB diblock copolymer formed miscible blends with PPO in the experimental range (lower than or equal to 70 wt% PPO). When the blend contained PPO whose composition is in the range of 40-50 wt%, the discontinuous phase of polybutadiene block in SB diblock copolymer, was changed to discrete phase, while polystyrene blocks containing PPO was changed to the continuous phase. A sudden decrease of the gas permeability and a sudden increase of the gas selectivity was observed at these blend compositions. A gas separation membranes having excellent mechanical properties and exhibiting advantages in gas permeability and selectivity could be fabricated from blends containing more than 50 wt% PPO.

Investigations with respect to the electrochemical properties of carbon paste electrode fabricated using polybutadiene binder (폴리부타디엔 결합재를 이용하여 만든 탄소반죽전극의 전기화학적 특성에 관한 연구)

  • Yoon, Kil-Joong
    • Analytical Science and Technology
    • /
    • v.20 no.1
    • /
    • pp.49-54
    • /
    • 2007
  • For the practical use as a biosensor, a rubber electrode bound by polybutadiene was newly devised for the determination of hydrogen peroxide. Then its electrochemical behaviors were investigated. The signal could be obtained at low electrode potential between 0.0 ~ -0.5 V (vs. Ag/AgCl) with a detection limit of $1.4{\times}10^{-4}M$ and its potential dependence was linear in the experimental range. Especially its Lineweaver-Burk plot showed a very good linearity giving the evidence of a good enzyme immobilization on the surface of the electrode. And mechanical stability of the electrode resulted from using rubber binder presented a new possibility for the practical use of biosensor.

Pyrolysis Paths of Polybutadiene Depending on Pyrolysis Temperature

  • Choi Sung-Seen;Han Dong-Hun
    • Macromolecular Research
    • /
    • v.14 no.3
    • /
    • pp.354-358
    • /
    • 2006
  • Polybutadiene (BR) was pyrolyzed at $540-860^{\circ}C$ and the effect of pyrolysis temperature on variations in the relative abundance of the major pyrolysis products (C4-, C5-, C6-, C7-, and C8-species) was investigated. Formation of the C4-, C5-, C6-, and C7-species competed with that of the C8-species. Relative intensity of the C8-species decreased with increasing pyrolysis temperature, while that of the C5-, C6-, and C7-species increased. Pyrolysis paths were became more complicated with increasing pyrolysis temperature. We suggested the operation of double bond migration and succeeding rearrangements for the formation of the C5- and C7-species and various rearrangements, including a double bond, for the formation of the C6-species at high temperature. The activation energies for the pyrolysis product ratios of(C5+C6+C7)/C4 and C8/C4 were used to explain the competition reactions to form the pyrolysis products.