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Aromatic Isocyanate

The Experts below are selected from a list of 120 Experts worldwide ranked by ideXlab platform

Kyu Ho Chae – 1st expert on this subject based on the ideXlab platform

  • polymerization of n 4 azidocarbonyl phenyl maleimide and n 4 n phenoxycarbonylamino phenyl maleimide polymers containing Aromatic Isocyanate precursors
    Polymer, 1999
    Co-Authors: Ji Young Chang, Kyu Ho Chae

    Abstract:

    Abstract N -[4-(Azidocarbonyl)phenyl]maleimide ( 3 ) and N -[4-( N ′-phenoxycarbonylamino)phenyl]maleimide ( 5 ) were polymerized and copolymerized with methyl methacrylate (MMA) or acrylic acid (AA) by initiation with AIBN. The resultant polymers were to have Aromatic isocyanato groups when heated. In the differential scanning calorimetry measurement, the polymers from monomer 3 showed a strong and broad exotherm around 130°C. Thermogravimetric analysis also showed a weight decrease corresponding to the elimination of nitrogen at that temperature. The formation of isocyanato groups was confirmed by infra-red measurement with varying the cell temperature. The coupling reaction of the polymer with N -4-(nitrophenyl)- L -prolinol, resulting in the formation of urethane bonds, was carried out in a quantitative yield. The crosslinked films from copolymers of 5 and MMA or AA were obtained when heated above 200°C. The cured films were insoluble in common organic solvents. With the copolymers with AA it was expected that carboxylic groups would react with isocyanato groups generated from urethane units when heated. The copolymer was degraded above 150°C. After curing, its thermal stability improved dramatically, no weight loss being observed up to 300°C.

Ji Young Chang – 2nd expert on this subject based on the ideXlab platform

  • polymerization of n 4 azidocarbonyl phenyl maleimide and n 4 n phenoxycarbonylamino phenyl maleimide polymers containing Aromatic Isocyanate precursors
    Polymer, 1999
    Co-Authors: Ji Young Chang, Kyu Ho Chae

    Abstract:

    Abstract N -[4-(Azidocarbonyl)phenyl]maleimide ( 3 ) and N -[4-( N ′-phenoxycarbonylamino)phenyl]maleimide ( 5 ) were polymerized and copolymerized with methyl methacrylate (MMA) or acrylic acid (AA) by initiation with AIBN. The resultant polymers were to have Aromatic isocyanato groups when heated. In the differential scanning calorimetry measurement, the polymers from monomer 3 showed a strong and broad exotherm around 130°C. Thermogravimetric analysis also showed a weight decrease corresponding to the elimination of nitrogen at that temperature. The formation of isocyanato groups was confirmed by infra-red measurement with varying the cell temperature. The coupling reaction of the polymer with N -4-(nitrophenyl)- L -prolinol, resulting in the formation of urethane bonds, was carried out in a quantitative yield. The crosslinked films from copolymers of 5 and MMA or AA were obtained when heated above 200°C. The cured films were insoluble in common organic solvents. With the copolymers with AA it was expected that carboxylic groups would react with isocyanato groups generated from urethane units when heated. The copolymer was degraded above 150°C. After curing, its thermal stability improved dramatically, no weight loss being observed up to 300°C.

Marwah Rayung – 3rd expert on this subject based on the ideXlab platform

  • comparative study of Aromatic and cycloaliphatic Isocyanate effects on physico chemical properties of bio based polyurethane acrylate coatings
    Polymers, 2020
    Co-Authors: Nurul Huda Mudri, Luqman Chuah Abdullah, Min Min Aung, Mek Zah Salleh, Dayang Radiah Awang Biak, Marwah Rayung

    Abstract:

    Crude jatropha oil (JO) was modified to form jatropha oil-based polyol (JOL) via two steps in a chemical reaction known as epoxidation and hydroxylation. JOL was then reacted with Isocyanates to produce JO-based polyurethane resin. In this study, two types of Isocyanates, 2,4-toluene diIsocyanate (2,4-TDI) and isophorone diIsocyanate (IPDI) were introduced to produce JPUA-TDI and JPUA-IPDI respectively. 2,4-TDI is categorised as an Aromatic Isocyanate whilst IPDI is known as a cycloaliphatic Isocyanate. Both JPUA-TDI and JPUA-IPDI were then end-capped by the acrylate functional group of 2-hydroxyethyl methacrylate (HEMA). The effects of that Isocyanate structure were investigated for their physico, chemical and thermal properties. The changes of the functional groups during each synthesis step were monitored by FTIR analysis. The appearance of urethane peaks was observed at 1532 cm−1, 1718 cm−1 and 3369 cm−1 while acrylate peaks were detected at 815 cm−1 and 1663 cm−1 indicating that JPUA was successfully synthesised. It was found that the molar mass of JPUA-TDI was doubled compared to JPUA-IPDI. Each resin showed a similar degradation pattern analysed by thermal gravimetric analysis (TGA). For the mechanical properties, the JPUA-IPDI-based coating formulation exhibited a higher hardness value but poor adhesion compared to the JPUA-TDI-based coating formulation. Both types of jatropha-based polyurethane acrylate may potentially be used in an ultraviolet (UV) curing system specifically for clear coat surface applications to replace dependency on petroleum-based chemicals.