Lan Tighzert

A new blocking agent of isocyanates

Abstract The synthesis of a new liquid blocking agent of isocyanates is described, the 2-formyloxyethyl methacrylate (FEMA). It possesses simultaneously two chemical functions on its molecule. The first function, bearing a labile hydrogen, can block an isocyanate group and the second, a double bond, can polymerise by radical pathway after the unblocking reaction. This fact represents a great advantage of avoiding the blocking agent release in atmosphere. Therefore the final material will contain two interpenetrated polymers polyurethane and polyacrylate. The blocking and unblocking kinetics using two aliphatic and aromatic diisocyanates and two diols were studied.

Synthesis and thermal properties of new copolyesters based on polycaprolactone

Abstract Several copolyesters were synthesized from carboxytelechelic poly( - caprolactone) and bis(2-hydroxyethyl)terephthalate (BHET), using a two-step method and a one-step method providing regular and random distributions of starting comonomers in the copolyester chains, respectively. Even with an identical molar comonomer composition, the properties of obtained copolyesters depended on the synthesis method, therefore the comonomer distribution along the polymer chain. The copolyester structure was characterized by 1H and 13C NMR and FTIR spectroscopy. The thermal properties of synthesized copolyesters were also studied by DSC and TGA demonstrating the influence of aromatic rings spread along the macromolecular polyester chain.