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Free radical photopolymerization initiated by polysilanes. Scrutiny of the initiation efficiency
Author(s) -
Peinado C.,
Alonso A.,
Catalina F.,
Schnabel W.
Publication year - 2000
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20000701)201:11<1156::aid-macp1156>3.0.co;2-#
Subject(s) - photopolymer , polymer chemistry , scrutiny , photochemistry , chemistry , polysilane , materials science , polymer science , organic chemistry , polymer , monomer , philosophy , theology
The polymerization of methyl methacrylate, MMA, and styrene, St, in Ar‐saturated tetrahydrofuran solution was photoinitiated at λ = 313 and 346 nm at 30°C by poly(methylphenylsilane), PMPSi, poly(hexylmethylsilane), PHxMSi) or poly(dihexylsilane), PdHxSi. The rate of monomer conversion was determined dilatometrically and Φ i , the quantum yield of initiation (number of kinetic chains started per absorbed photon), was calculated with the aid of the measured absorbed dose rate and values of k p / k t 1/2 taken from the literature. Φ i values in the order of 10 –1 were obtained. Typical results found with PdHxSi are: Φ i = 0.19 (0.18) for MMA at λ inc = 313 (346) nm, and Φ i = 0.34 for St at λ inc = 346 nm. Under analogous conditions Φ i = 0.24 ± 0.03 was obtained for the system benzoin/MMA at λ inc = 346 nm. The Φ i values found for the polysilanes are about two orders of magnitude larger than the value reported in the literature for the system St/PMPSi ( Φ i = 10 –3 ). It is concluded that the polysilanes tested in this work act as efficient photoinitiators for free radical polymerization of MMA and St.