Preparation, characterization and thermal properties of tetramethylbisphenol F epoxy resin and mixed systems

Synthesis and characterization of a novel resin monomer with low viscosity

OBJECTIVE

In this study, we designed and synthesized a novel macromolecule (tetramethyl bisphenol F acrylate, TMBPF-Ac) with low viscosity, excellent mechanical properties, and good biocompatibility. It could be used as a monomer for dental resin composites, which could reduce the risk of human exposure to bisphenol A derivatives in the oral environment. In addition, the monomer could be used without diluent, thereby avoiding the negative effect of a diluent METHODS: TMBPF-Ac was synthesized by a multistep condensation reaction. Its structure was confirmed by ¹H NMR spectra. Different resin mixtures were prepared, and then a number of performance and cytotoxicity tests were performed on these specimens.

RESULTS

¹H NMR spectra showed that the structure of TMBPF-Ac was in accordance with the design. The viscosity of TMBPF-Ac was obviously lower than that of bisphenol-A diglycidyl methacrylate. The three kinds of resins used in this study were in line with ISO 4049:2009 and ISO 10993-5:2009. TMBPF-Ac-based resin had better physical and biological properties.

Bio-Based Aromatic Epoxy Monomers for Thermoset Materials

The synthesis of polymers from renewable resources is a burning issue that is actively investigated. Polyepoxide networks constitute a major class of thermosetting polymers and are extensively used as coatings, electronic materials, adhesives. Owing to their outstanding mechanical and electrical properties, chemical resistance, adhesion, and minimal shrinkage after curing, they are used in structural applications as well. Most of these thermosets are industrially manufactured from bisphenol A (BPA), a substance that was initially synthesized as a chemical estrogen. The awareness on BPA toxicity combined with the limited availability and volatile cost of fossil resources and the non-recyclability of thermosets implies necessary changes in the field of epoxy networks. Thus, substitution of BPA has witnessed an increasing number of studies both from the academic and industrial sides. This review proposes to give an overview of the reported aromatic multifunctional epoxide building blocks synthesized from biomass or from molecules that could be obtained from transformed biomass. After a reminder of the main glycidylation routes and mechanisms and the recent knowledge on BPA toxicity and legal issues, this review will provide a brief description of the main natural sources of aromatic molecules. The different epoxy prepolymers will then be organized from simple, mono-aromatic di-epoxy, to mono-aromatic poly-epoxy, to di-aromatic di-epoxy compounds, and finally to derivatives possessing numerous aromatic rings and epoxy groups.

Novel optically active poly(amide-thioester-imide)s containing l-α-amino acids and thiadiazol anticorrosion group

Here, for the first time, we report the synthesis of a new class of optically active polymers, poly(amide-thioester-imide)s (PATEI)s, containing flexible and anticorrosion linkages. Step growth polymerization of a novel diamine with diacids containing amino acid and trimellitylimide groups in tetrabutylammonium bromide, in the molten state, which acts as a molten ionic salt medium, was carried out. The obtained polymeric materials were of the nanoscale size and were assembled by filamentary particles as shown by field-emission scanning electron microscopy micrographs, which were distributed uniformly and randomly, with an average nanosize diameter of about 40 nm. The polymeric samples were readily soluble in a variety of common organic solvents and formed low-colored and flexible thin films via solution casting. The values of absorption edge wavelength ( λ0) were determined by ultraviolet–visible spectroscopy, and all of the resulting PATEI films exhibited high-optical transparency. According to x-ray diffraction patterns, all the PATEIs were amorphous. The structure of PATEIs were also characterized by Fourier-transform infrared spectroscopy, Proton-nuclear magnetic resonance, elemental, and thermogravimetric analysis techniques. The effect of ultrasound on the morphology of polymers was also investigated. This study confirmed that the size of polymer particles decreased and there was a change in their morphology.