Bisphenol A Derivatives Research Articles

Theoretical elucidation on mechanism and reactivity of bisphenol A derivatives as inhibitors and radical scavengers in methacrylate polymerization

To elucidate the mechanism and activity difference of bisphenol A derivatives (BSADs), i.e. hydroquinone, 2,2′-biphenol, 4,4′-biphenol, bisphenol A and diethylstilbestrol, as inhibitors and radical scavengers in methyl methacrylate (MMA) polymerization, a combined quantum chemical method, labeled as (RO)B3LYP/6-311+G(2d,2p)//AM1/AM1, was employed to calculate O–H bond dissociation enthalpies (BDEs) and ionization potentials (IPs) for these compounds. The calculation results reveal that BSADs scavenge radicals generated during MMA polymerization through a direct H-atom transfer process. Furthermore, the difference in inhibition activity and stoichiometric factors for BSADs was elucidated by the O–H BDEs. In addition, substituent effects on BDE were employed to give a deeper insight into the structure–activity relationships for BSADs.

Derivatisation of 4-nonylphenol and bisphenol A with halogenated anhydrides

The aim of this work is to synthesize and characterise the halogenated derivatives of the endocrine disrupting compounds (EDCs) 4-nonylphenol (4-NP) and bisphenol A (BPA). Characterisation was performed after gas chromatographic (GC) separation on-line coupled to mass spectrometric (MS) detector and a Fourier Transform Infrared (FTIR) spectroscopic detector. Further structure elucidation was done applying Nuclear Magnetic Resonance spectroscopy (NMR). Two different approaches for the preparation of derivatives were evaluated. At first trifluoroacetyl derivatives were synthesized by the reaction of trifluoroacetic acid (TFA) anhydride and the EDCs in acetonitrile at a temperature of 50 degrees C for 30 minutes. In a second step the 4-NP was derivatised using trichloroacetic acid anhydride and triethylamine in diethyl ether at 20 degrees C for 30 minutes. After synthesis the halogenated NP and BPA derivatives were characterised applying GC/MS, GC/FTIR and NMR. Three indices for a successful derivatisation were observed: El-GC/MS proved a complete derivatisation presenting a characteristic fragmentation pattern for each derivative. The IR spectra obtained by GC/FTIR after derivatisation and separation confirmed the loss of the phenolic O-H stretching vibration at 3,600 cm(-1) while typical absorptions for halogenated compounds now were observed. The NMR-spectra contained the predicted resonance signals.

Synthesis and Properties of Oligomers Containing 1,4-Bis(thiophenene)buta-1,3-diyne and Bisphenol-A Derivatives

Department of Chemistry, Yonsei University, Seoul 120-749, KoreaReceived August 13, 2001Keywords : Oligomer, 1,4-Bis(thiophene)buta-1,3-diyne, Bisphenol-A, Absorption, Fluorescence.Conjugated polymers containing organic conjugate groupssuch as thiophene and acetylene have received considerableattention for the potential applications of electronic andoptical materials in recent years.

Improving the Process Capability of SU-8. Part II.

SU-8 Resists are used widely in the development and fabrication of MEMS devices [1-4]. The resist's images are the product of photochemical and thermal cationic processes and result in vertical sidewalls and high aspect ratio features. These are among SU-8's most desirable attributes. The process, which creates the desirable images, however, generates considerable internal stress, which produces cracked features. It would be beneficial, therefore, to investigate modifications of the SU-8 resist formulation which incorporate materials that will attenuate stress cracking without significant image degradation.Work reported previously by IBM focused on compositions containing SU-8 targeted for applications in which lithographic performance could be sacrificed for high flexibility [5]. In this paper we present our results of studies directed toward the selection of materials compatible with SU-8, which will significantly reduce cracking and also retain high aspect ratios images and vertical sidewalls. To this end, we examined mono and polyfunctional epoxides from the following chemical classes; siloxanes, urethanes, cycloaliphatics, a bicycloaliphatic copolymer with phenol, bisphenol-A derivatives, a long chain aliphatic polyol and some long chain aliphatic esters.This work allowed us to identify compositions having improved crack resistance and adhesion over standard SU-8 resist, without sacrificing lithographic performance, which may provide benefits for applications such as a dielectric barrier.

Studies on the Synthesis of Polyarylates with Allylic Side Groups. Part 1. Polyarylates from 2,2-bis (3-allyl-4-hydroxyphenyl)propane and Isophthaloyl Chloride

Conditions of synthesis of diallyl derivatives of bisphenol-A via a Claisen rearrangement reaction and the preparation of polyarylates from these derivatives via interfacial polycondensation with isophthaloyl chloride were established. The structure of polymers was confirmed by the methods of 1H-NMR, IR, and UV/Vis spectroscopy and elementary analysis. The results of intrinsic viscosity determinations and thermal analysis revealed the high molecular weight and considerable thermal resistance of these polyarylates.

Studies on the Synthesis of Polyarylates with Allylic Side Groups. Part 1. Polyarylates from 2,2-bis (3-allyl-4-hydroxyphenyl)propane and Isophthaloyl Chloride

Conditions of synthesis of diallyl derivatives of bisphenol-A via a Claisen rearrangement reaction and the preparation of polyarylates from these derivatives via interfacial polycondensation with isophthaloyl chloride were established. The structure of polymers was confirmed by the methods of 1H-NMR, IR, and UV/Vis spectroscopy and elementary analysis. The results of intrinsic viscosity determinations and thermal analysis revealed the high molecular weight and considerable thermal resistance of these polyarylates.

Synthesis and photosensitized homo‐ and block copolymerization of a bisphenol‐A derivative of dibenz[b, f]azepine

A bisphenol-A derivative of dibenz[b,f]azepine (DBA-Bisphenol-DBA) was synthesized and characterized. Sensitized photopolymerization of the DBA-Bisphenol-DBA was studied in detail. The usefulness of N-acyldibenz[b,f]azepine groupings in promoting photochemically induced linking of the related molecules is further demonstrated by block copolymerization of DBA-Bisphenol-DBA and polystyrene having terminal dibenz[b,f]azepine substituents. Those reactions arise through benzophenone-sensitized photocyclodimerization of the central double bond of the dibenz[b,f]azepine moieties.

Degradation of epoxy polymers. Part 5—Photo-degradation of bisphenol-A diglycidyl ether cured with ethylene diamine

The principal characteristics and products of thermal degradation of a commercial epoxy resin, prepared by reaction of 2,2-bis-(4′-hydroxy phenyl)propane (bisphenol-A) with 1-chloro-2,3-epoxy propane (epichlorhydrin) and cross-linked (cured) with ethylene diamine, have been studied. Products positively identified are hydrogen, traces of methane and carbon monoxide, carbon dioxide, ammonia and water in relatively large yield, isopropyl and isopropenyl benzene, phenol, cresols, xylenols and possibly benzo-furanyl and benzo-pyranyl derivatives of bisphenol-A. The polymer simultaneously develops a yellow colour. Mechanisms of degradation have been suggested.