• Title/Summary/Keyword: low molecular wight

Search Result 3, Processing Time 0.016 seconds

Effect of Solvent Extraction on the Low Molecular Weight and Volatile Organic Compounds of Polycarbonate (폴리카보네이트의 저분자량 화합물 및 휘발성 유기물에 대한 접촉추출 영향)

  • Choi, Su-Jung;Yoon, Kyung-Hwa;Hwang, In-Hye;Lee, Chang-Young;Kim, Hee-Seung;Yoo, Seung-Yoon;Kim, Youn-Cheol
    • Applied Chemistry for Engineering
    • /
    • v.21 no.5
    • /
    • pp.532-536
    • /
    • 2010
  • A study on the volatile organic compounds (VOCs) and low molecular weight (LMW) amount which is contained within bisphenol A polycarbonate (PC) was performed by the solvent extraction with ketone type solvents (acetone, butanone, pentanone). The LMW amount of untreated PC was 2.6 wt%, but the values of treated samples with acetone and pentanone were 0.96 and 1.53 wt%, respectively. Acetone is a more effective solvent than pentanone on the LMW extraction. Methylene chloride (MC) and toluene were certified and quantified by GC-Mass experiments, and the quantitative results indicated the fact that the pentanone was the effective solvent on VOC extraction. Focused on the change of VOCs and LMW amount, the use of co-solvent might be more useful, and the experimental results of co-solvent extraction showed that the optimum condition was 50 : 50 volume percent.

Syntheses of 70% Solids Acrylic Resin and Comparative Study in Physical Properties as Acrylic Urethane Resin Coatings (고형분 70% 아크릴수지 합성과 아크릴-우레탄 도료의 도막물성 비교 연구)

  • Kim, Seong-Kil;Park, Hyong-Jin
    • Journal of the Korean Applied Science and Technology
    • /
    • v.38 no.2
    • /
    • pp.476-487
    • /
    • 2021
  • To prepare acrylic resin coatings containing 70% of solids, we used n-butyl methacrylate(BMA), methyl methacrylate(MMA), 2-hydroxyethyl methacrylate(2-HEMA), and acetoacetoxyethyl acrylate(AAEA), caprolactone acrylate(CLA) as raw materials, the glass transition temperature(Tg) of acrylic copolymer was adjusted around 50 ℃. The viscosity and molecular weight of the acrylic resins was increased with increasing OH values. Di-tert-amyl peroxide was found to be the suitable initiator to get high-solids acrylic resins. The optimum reaction conditions found in the study are 5 wt% of initiator, 4 wt% of chain transfer agent, 4 hrs of dropping time, and 140 ℃ of reaction temperature. The structure of the synthesized resins were characterized by FT-IR and 1H-NMR spectroscopy. Number average molecular weight of 1900~2600 and molecular wight distribution of 1.4~2.1 were obtained. Crosslinked acrylic urethane clear coatings were obtained by curing reaction between the synthesized acrylic resins and hexamethylene diisocyanate trimer(Desmodur N-3300), the equivalent ratio of NCO/OH was 1.2/1.0. The physical properties from the following studies were carried out: viscosity(Zahn cup #2), adhesion, drying time, pot-life, pensil hardness, and 60° specular gloss. Various properties of the acrylic urethane clear coatings were also evaluated on the coating specimens. Adhesion property to a substrate, drying time, pot-life, pencil hardness, and 60° specular gloss of prepared paint showed quite good properties. Futhermore, prepared paint containing 10% of CLA showed quite good properties for adhesion, low viscosity and high hardness.