Study on Environmental Impact of Highly-performance Electrical Insulation Resins: Synthesis of NMP-free and Bio-based Wire Enamels

The research reported in this thesis is the result of a strong partnership between the University of Camerino and ELANTAS Europe S.r.l. The strong collaboration between the university and several companies allows students to do research with an industrial approach and at the same time to face with challenges given by working life. The work was carried out among the laboratory of Organic Chemistry of Prof. Enrico Marcantoni at the University of Camerino (Camerino, Italy) and the R&D laboratory of ELANTAS Europe in Ascoli Piceno (Italy). Elantas Europe is a leading manufacturer of insulating and protective materials. In the site of Ascoli Piceno, Elantas Europe manufactures high-performance enamels for use as magnet wire coatings. They are coated on the surface of copper or aluminum wires and cured to form an electrical insulation film. Magnet wire enamels, in general, consist of polymeric resins dissolved in organic solvents. Apart from the basic electrical insulation requirement, this means, depending on the end-use application, wire enamels provide high thermal and mechanical stability, flexibility, moisture resistance, and long service life of the insulation. The main end use application areas are transportation, automotive, household appliances, motors, transformers, industrial electronics, or power generation. The work made in these three years concern the environmental impact of some industrial polymeric materials. In particular, the aim of the work was to replace the well-known and most used solvent in wire enamel, N-methylpyrrolidone (NMP), with a safer and greener solvent in polyamide-imide (PAI) and polyimide (PI) precursor, that is, polyamic-acid (PAA). In addition, a part of the thesis concerns the synthesis and characterization of polyimide precursor and polyester-imides (PEI) wire enamel using bio-based diamines (obtained from fatty acid dimers) replacing totally 4,4’-oxydianiline (ODA) and 4,4’diaminodiphenilmethane (MDA). Chemical structure, molecular weight distribution, thermo-mechanical and electrical properties of obtained polymers were determined and discussed. This work was carried out almost entirely in R&D laboratories of Elantas Europe plant in Ascoli Piceno. A second part of the thesis work was carried out in the laboratory of organic chemistry of Prof. Enrico Marcantoni at the University of Camerino, chemistry department. The work was focused on the development of an innovative method for the determination of residual isocyanate monomers in different batches of solvent-based polyamide (PA) resin.