Poly(p-phenylene) graft copolymers with polytetrahydrofuran/polystyrene side chains

• Published in: Polymer (Guilford) 2002-04, Vol.43 (8), p.2141-2149
• Main Authors: CIANGA, Ioan, HEPUZER, Yesim, YAGCI, Yusuf
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polycondensation; Preparation, kinetics, thermodynamics, mechanism and catalysts
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(02)00002-2

1,4-Dibromo-2,5-bis(bromomethyl)benzene was used as a bifunctional initiator in cationic ring opening polymerization (CROP) of tetrahydrofuran. The resulting macromonomer, with a central 2,5-dibromobenzene ring, was reacted in combination with 2,5-dihexylbenzene-1,4-diboronic acid by a Suzuki coupling, in the presence of Pd(PPh sub 3 ) sub 4 as catalyst, leading to a poly(p-phenylene) (PPP) with alternating polytetrahydrofuran (PTHF) and hexyl side chains. A polystyrene (PSt) based macromonomer with a central benzene ring bearing cyclic boronic acid propanediol diester groups, synthesized by atom transfer radical polymerization (ATRP), was also used as partner for PTHF in the cross-coupling reaction. A PPP with alternating PSt and PTHF side chains was obtained. PTHF macromonomer was also homopolymerized by a Yamamoto reaction. The resulting PPPs have high solubility in common organic solvents at room temperature. The new polymers were characterized by GPC, exp 1 H NMR, exp 13 C NMR, IR and UV analysis. Thermal behavior of the precursor PTHF macromonomer and the final polyphenylenes were investigated by TGA and DSC analyses and compared.