16618

Chemical Modification of some 4-Chloromethyl Styrene Polymers with Highly Sterically Hindered Tris(trimethylsilyl)methyl Groups

Safa Kazem D نويسنده , Eram Hassan A نويسنده , Nasirtabrizi Mohammad H نويسنده

249

257

9

4-c hloromethYI styrene (CMS) was copolymerized with different monomers such as 2-ethyl hexyl acrylate (EHA), 1,1-dichloroethylene (DCE), N-viny1-2-pyrrolidone (NVP) acrylonitrile (AN) and methacrylonitrile (MAN) by free radical polymerization method at 70±1°C using a,aי-azobisisobutyronitrile (AIBN) as an initiator and the copolymers (I-V) collected respectively. The copolymer compositions were obtained using related 1H NMR spectra and the polydispersity of the copolymers was determined using gel permeation chromatography (GPC). Highly sterically hindered tris (trimethylsilyl)methyl (Tsi=trisyl) substituents were then covalently linked to the I, II and III copolymers. When copolymers IV and V are treated with TsiLi, cross-linking is observed and no further modification is possible. Differential scanning calorimetry (DSC) showed that incorporation of Tsi substituents in the side chains of copolymers increases the rigidity of the polymers and subsequently, their glass transition temperatures. All the resulted polymers were characterized by FTIR and 1H NMR spectroscopic techniques.

1200447