Attila Güngör

Preparation and characterization of novel UV-curable urethane methacrylate difunctional monomers and their structure-property relationships, 1

Four new UV-curable cross-linking agents namely 2,2-bis(4-β-ethoxy urethane ethyl methacrylate phenyl)propane (HEPAIEM), 2,2-bis(4-β-ethoxy urethane ethyl methacrylate phenyl)6Fpropane (HEPFAIEM), 2,2-bis(4-β-ethoxy urethane ethyl methacrylate-3,5-dibromo phenyl)propane (TBHEPAIEM), and 5-tert-butyl-1,3-bis(4-ethoxy urethane methacrylate phenyl)benzoylbenzene (tBuHEPBIEM), which can be good candidates for UV-curable coating applications, were synthesized by reacting isocyanato ethyl methacrylate (IEM) with four different diols. The structures of the monomers thus prepared were characterized by FTIR, mass and 1 H NMR spectroscopies. Introduction of new difunctional cross-linking agents affected the mechanical and physical properties of UV-cured films. Addition of 10% cross-linking agents into the formulations caused an increase both in tensile strength and elongation, when compared with widely used di(ethylene glycol)diacrylate (DEGDA) containing films. Elongation values of TBHEPAIEM containing films were exceptions. Gel contents of the UV-cured polymeric films were found to be between 88-98%. Thermogravimetric analysis showed that there were not any noticeable changes in thermal oxidative stability of the films compared with DEGDA containing ones. On the other hand, HEPFAIEM and TBHEPAIEM containing films showed increases in char yields due to the presence of F and Br in their structures. Introduction of the new difunctional monomers lowered the water absorption values of the films somewhat proportional to the methyl group content of the x-linkers.

Synthesis of a hexafluoropropylidene‐bis(phthalic anhydride)‐based polyimide and its conducting polymer composites with polypyrrole

A new electrically conducting composite film from polypyrrole and 4,4*- (hexafluoroisopropylidene) -bis(phthalic anhydride)-based polyimide was prepared. Pyrrole and the dopant ion can easily penetrate through the polyimide substrate and electropolymerize on the platinum (Pt) electrode due to the swelling of the polyimide on the metal electrode. The electrochemical properties of polypyrrole-polyimide (PPy/ PI) composite films have been investigated by using cyclic voltammetry. The PPy/PI composite film is suitable for use as the electroactive material owing to its stable and controllable electrochemical properties. The electrical conductivity of composites falls in the range 0.0035-15 S/cm. Scanning electron micrograph, FTIR, and thermal studies indicate that PPy and PI form a homogeneous material rather than a simple mixture. q 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3009-3016, 1997

Preparation and Characterization of Novel UV-Curable Ester Methacrylate Crosslinking-Agents and Their Structure-Property Relationships, 2

Four, new difunctional monomers namely 2,2-bis(4-ethoxyacrylatephenyl)propane (HEPAAC), 2,2-bis(4-ethoxyacrylatephenyl)6Fpropane (HEPFAAC), 2,2-bis(4-ethoxyacrylate-3,5-dibromphenyl)propane (TB-HEPAAC) and 5-tert-butyl-1,3-bis(4-ethoxyacrylate benzoyl)benzene (tBuHEPBAC) containing acrylic moiety, which can be good candidates as x-linking agents for UV curable coating applications, were synthesized by reacting acryloyl chloride with four different diols. The structures of the monomers thus prepared were characterized by FTIR, mass and 1 H NMR spectroscopies. Introduction of 10% of these new monomers into the UV-curable formulations, caused different behaviors in tensile strengths and elongations, when compared with diethylene glycol diacrylate (DEGDA) containing films. Both elongation and tensile strength values were decreased for TBHEPAAC and tBuHEPBAC containing films, while the same values of the films containing HEPAAC and HEPFAACs increased. Gel contents of the UV-cured polymeric films were found to be between 88-98%. Thermogravimetric analysis showed that there were not appreciable changes in thermal stability of the films compared to DEGDA containing ones. On the other hand, HEPFAAC and tBuHEPAAC containing films showed increased in char yields due to the presence of F and Br in their structures. Introduction of the new difunctional monomers lowered the water absorption values of the films somewhat proportional to the methyl group content of the x-linkers.

Effects of nonreactive resins on the properties of a UV-curable methacrylated urethane resin

The effects of two nonreactive conventional-type resins, a bisphenol-A-based phenoxy resin PAPHEN-301 and aromatic-based PETROLEUM RESIN, on the mechanical, thermal, and physical properties of methacrylated urethane resin-based UV-curable formulations were studied. A methacrylated urethane prepolymer was synthesized from isocyanatoethyl methacrylate (IEM) and polytetrahydrofurandiol (PTHF) via a one-step reaction. An increase in PAPHEN-301 content caused an increase both in tensile strength and elongation values of UV-cured polymeric films. On the other hand, an increase in PETROLEUM RESIN content caused a decrease both in tensile strength and elongation values of the polymeric films. However, thermooxidative properties were not affected by the introduction of either resin. It was also found that the water-absorption capacities of the UV-cured methacrylated urethane films depended on the type and amount of the nonreactive resins.

Thermal and Mechanical Properties of Poly(arylene ether ketone)s Based on 5-tert-Butyl-1,3-bis(4- fluorobenzoyl)benzene

An aromatic bishalide, 5-tert-butyl-1,3-bis(4-fluorobenzoyl)benzene (2) was synthesized in high yield and purity by the reaction of 5-tert-butylisophthaloyl chloride (1) and fluorobenzene and polymerized by nucleophilic substitution reaction with commercially available aromatic bisphenols to prepare a series of high molecular weight poly(arylene ether ketone)s containing pendant tertiary butyl groups. The effect of molecular structure on the physical, thermal, mechanical and adhesion properties of the polymers was investigated.