Graft copolymerization of p-acryloyloxybenzoic acid and p-methacryloyloxybenzoic acid onto isotactic polypropylene

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye

Tezin Onay Tarihi: 2004

Öğrenci: SEDAT ÇETİN

Danışman: İSMAİL TEOMAN TİNCER

Özet:

The monomers, p-acryloyloxybenzoic acid (ABA) and p-methacryloyloxybenzoic acid (MBA) were synthesized by condensation reaction of corresponding acid chlorides with p-hydroxybenzoic acid in alkaline medium. The polymerization of the monomers were studied by several techniques. Polyacryloyloxybenzoic acid (PABA) was obtained by ?-radiation induced, solution and bulk melt polymerization by initiation of dicumyl peroxide (DCP). Polymethacryloyloxybenzoic acid (PMBA) could be obtained by only bulk melt polymerization. The graft copolymerization of the monomers onto isotactic polypropylene, IPP, was successfully carried out only with bulk melt polymerization. The IPP used in the graft copolymerization was firstly subjected to ?-radiation to create active sites for grafting. The graft copolymerization of the monomers, ABA and MBA onto IPP were initiated by these active sites. The grafting was studied at constant concentration of the monomers in the reaction mixture (50%) and at different reaction temperatures (170, 185, 202, 215 and 225°C). The maximum grafting of PABA and PMBA were found to be 33.1% and 33.9% in the graft copolymers, respectively. The maximum grafting was reached in shorter times at higher temperatures, and it also increased with the increase of concentration of the monomers in the reaction medium. The graft copolymerization was also carried out by using initiator, DCP at 170°C, however, the grafting extent was lower due to the homopolymerization of the monomers and the direct reactions between peroxides of initiator and peroxides on IPP. The graft copolymers were characterized by several techniques, DSC, WAX, TG/IR, MS, SEM and mechanical testing. The formation of both crystalline forms of (?1 and ?2) were observed in the products obtained at 170°C. The graft copolymerization of ABA did not have any significance on the formation of both forms of ? form,