IN SITU PREPARATION OF NON HALOGENATED FLAME RETARDANT POLYAMIDES

In this research project the work was focused on the development of flame retardant polyamides by using two different approaches: the copolymerization with phosphor-containing molecules (one of the most promising class of NHFR) and the insertion of surface-modified mineral nanoparticles (another class of NHFR with high potential interest). The choice of polyamide is owed to the fact that an high amount of this material needs flame retardant property, considering its use in moulded manufactured articles with application in risk conditions (electric covering, control units..) and its use in the production of fibre (carpeting, drapery..) that should need a specific flame retardant material (obtainable by copolymerization because compounded materials aren’t usable) that doesn’t exist on the market (while there is an example of a PET FR[4]). Regarding intellectual property there are some patents[5] on the use of a minimal quantity of phosphor-based comonomers in copolymerization with nylon 66; however at the beginning of the PhD, there weren’t on the market polymeric materials obtained according to these patents. Polyamide 6 has been chosen because it is a commodity obtained by polymerization of an -amino acid; this kind of polymerization gives less problems in comparison with a polycondensation of a diacid and a diamine (i.e gelification problems), allowing a better study of copolymerization.