Elisa Zeno

Activation of solid polymer surfaces with bifunctional reagents

An original procedure is described which calls upon the heterogeneous grafting of bifunctional molecules onto a reactive polymeric surface, leaving one of the functions available for further exploitation. The principle of this strategy is to use reagents characterised by a rigid planar structure bearing the two active moieties at opposite sites of the molecule. The examples provided include the reactions of lignocellulosic fibres with 1,4-phenyl diisocyanate and 1,2,4,5-benzenetetracarboxylic anhydride, which give rise to their surface activation through the incorporation of covalently bound isocyanate or anhydride functions. © 2001 Society of Chemical Industry

Flexible and high performing polymer electrolytes obtained by UV-induced polymer–cellulose grafting

A novel UV-induced procedure, in the presence of glycidyl acrylate and proper radical/cationic photoinitiators, is here proposed to promote the in situ grafting of a methacrylic polymer network to the surface of natural cellulose fibers. As a result, composite polymer membranes reinforced by cellulose handsheets are obtained and demonstrate excellent mechanical features. The reactivity of the monomers is studied by FT-IR in real time measurements and the successful grafting is confirmed by surface spectroscopies. The polymer membranes prepared show high elastic modulus and tensile resistance and maintain high flexibility even after activation by swelling into a standard liquid electrolyte solution. The swelling procedure allowed us to obtain high ionic conductivity and remarkable electrochemical behavior when tested in laboratory scale lithium polymer cells. The system shows attractive features such as intrinsic safety, eco-compatibility, and low production cost and industrialization potentials, and is highly suitable for the rapidly expanding field of Li-based flexible batteries.

MODIFICATION OF CELLULOSE BY UV-GRAFTING OF AN ORGANO-POLYSILAZANE OLIGOMER

Abstract The modification of cellulose fibers by grafting specific functions could improve their quality and allow their use for the development of new products. In this work we report about the functionalization of a cellulose fiber network (filters) with organo-polysilazane oligomers by UV-irradiation. Photo-induced grafting, as assessed by contact angle and TGA measurements, was successful: an interesting enhancement of thermal resistance and mechanical properties was obtained. Water repellency was also achieved.