Oligosiloxanes containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diallyl functional monomer is synthesized through the Mannich and ring closing reaction of 4,4′‐isopropylidenediphenol (bisphenol A), formaldehyde and allylamine. Hydrosilylation reaction of the resulting diallylic monomer (B‐ala) with 1,1,3,3‐tetramethyldisiloxane (TMDS) in the presence of Pt catalyst yields the corresponding poly(B‐ala‐tetramethyl disiloxane)s (PBTMDS) with the molecular weights in the range of 1800–4100 Da. The structures of the precursor diallyl monomer and the resulting polymers are confirmed by FT‐IR and 1H NMR analysis. Curing behavior of both the monomer and polymers has also been studied by Differential Scanning Calorimetry (DSC). Flexible free standing transparent films of the oligosiloxanes are obtained by solvent casting from dichloromethane solution on Teflon plates. The films preserve shape and, to some extent, toughness after thermal curing between 100 and 180 °C. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis (TGA). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 804–811, 2009

Two thioxanthone derivatives with fluorene additional chromophoric groups, namely thioxanthone-fluorenecarboxylic acid (TX-FLCOOH) and thioxanthone-fluorene sodium carboxylate (TX-FLCOONa), as visible light absorbing oil-and water-soluble photoinitiators, respectively, were synthesized and characterized. Their ability to initiate photopolymerization of methyl methacrylate (MMA), 2-(2-phosphonoethoxymethyl)acrylic acid ethyl ester (EAEPA), and a multifunctional monomer, trimethylolpropane triacrylate (TMPTA), were examined. The initiation efficiency of TX-FLCOOH was compared with the parent thioxantone (TX) both in the presence and in the absence of a co-initiator, and TX-FLCOOH was found to be more effective in all cases. Photopolymerization and laser flash photolysis studies revealed that depending on the concentration initiation by TX-FLCOOH occurs by intra-and intermolecular H-abstraction of the triplet 3 (TX-FLCOOH)*. No polymerization was observed when TX-FLCOONa was used as photoinitiator in the absence of a co-initiator. However, TX-FLCOONa acts as an efficient initiator in the visible range in the presence of H donors in water.

A polystyrene copolymer (PS-B-DMAB) possessing both benzophenone and dimethylamino moieties in the side chain was synthesized by a combination of nitroxide-mediated radical polymerization (NMRP) and simultaneous double "click" reactions. First, a random copolymer of styrene (S) and chloromethylstyrene (CMS) with 32 mol % CMS content was prepared by NMRP process. Then, chloromethyl groups were converted to azide groups by reacting with NaN 3 in DMF. The other two click components, namely, propargyl benzophenone (Pr-B) and propargyl 4-(dimethylamino)benzoate (Pr-DMAB), were prepared independently by the etherification and esterification reactions, respectively. Then, in the final stage, the obtained alkyne functional chromophoric (Pr-B) and hydrogen-donating (Pr-DMAB) molecules were anchored to azide-modified polystyrene (PS-N 3 ) in one-step by "click chemistry". The final polymer (PS-B-DMAB) and the intermediates were characterized in detail by spectral analysis and laser flash photolysis studies. The resulting polymer possesses absorption characteristics similar to bare bezophenone. The one-component photoinitiating nature of PS-B-DMAB was demonstrated by photopolymerization of mono-and multifunctional monomers, namely, methyl methacrylate (MMA) and trimethylolpropane triacrylate (TMPTA), respectively.

Polysiloxanes containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diallyl functional benzoxazine monomer is synthesized through the Mannich and respective ring closing reactions of 4,4′‐isopropylidenediphenol (bisphenol A), formaldehyde, and allyamine. Subsequent hydrosilylation reaction of the resulting allylic monomer (B‐ala) with 1,1,3,3‐tetramethyldisiloxane (TMDS) in the presence of Pt catalyst yields the corresponding oligo(B‐ala‐tetramethyldisiloxane)s (OBTMDS). Using the anionic polymerization route, OBTMDS was then converted to poly(bisbenzoxazinedimethylsiloxane)s (PBDMSs) by reacting with readily available cyclic oligomer octamethylcyclotetrasiloxane (D4) or decamethylcyclopentasiloxane (D5) in the presence of tetrabutylammonium hydroxide as catalyst. The structures of the precursor diallyl monomer, the intermediate oligomer, and the resulting polymers are confirmed by Fourier transform infrared and 1H NMR analysis. Curing behavior of the products at various stages has also been studied by differential scanning calorimetry. Flexible transparent films of the PBDMSs are obtained by solvent casting. Thermal properties of the cured polymers are also investigated by thermogravimetric analysis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

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