Graft Copolymers of Polypropylene Films. 1. Radiation-induced Grafting of Mixed Monomers

✍ Scribed by El-Salmawi, K. M.; El-Naggar, A. M.; Said, H. M.; Zahran, A. H.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 313 KB
• Volume: 42
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199702)42:2<225::aid-pi703>3.0.co;2-e

✦ Synopsis

Radiation graft copolymerization of comonomer mixtures of acrylic acid (AAc) and styrene (S) onto polypropylene (PP) Ðlms by the mutual method has been investigated. The e †ect of di †erent factors that may a †ect the grafting yield, such as inhibitor concentration (MohrÏs salt), solvent composition (MeOH and radiation dose and dose rate, was studied. It was found that MohrÏs H 2 O), salt was very e †ective when the content of AAc in the comonomer mixtures was low. However, the addition of 1É25 wt% of MohrÏs salt reduced homopolymer formation and enhanced the grafting process. Graft copolymerization in the presence of a solvent mixture composed of methanol and water was found to a †ord a higher grafting yield than in pure methanol, regardless of the composition of the comonomer mixture used. However, the highest degree of grafting was obtained at a solvent composition of 20%

MeOH and a comonomer mixture H 2 O : 80% of 20% AAc : 80% S. An attempt was made to determine each PAAc and PS fraction by di †erent methods in the graft copolymer obtained. Elemental analysis indicated that the PAAc fraction with respect to PS in the graft copolymer decreased with increasing AAc ratio in the comonomer feed solution. The rough assessment of these fractions by IR spectroscopy showed similar trends. The reactivity ratios of AAc and S monomers determined in the present graft copolymerization system were found to be 0É45 and 1É3, respectively.