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The polysiloxanes end-capped with oxetane group (PSiO-H and PSiO-L) were synthesized via hydrosilylation reaction based on α,ω-dihydrogen-terminated polydimethylsiloxanes with a higher (0.23%, PDSi-H) and lower (0.12%, PDSi-L) hydrogen amount. The molecular structures were characterized by FT-IR and 1H NMR spectroscopy. The polysiloxanes were added into a commercial oxetane-based resin, 3,3′-(oxydi(methylene)) bis(3-ethyloxetane) (DOX), as an additive to prepare a series of cationic UV curable formulations. The photo-DSC results showed that the maximum photopolymerization rate decreased while the oxetane conversion increased with the polysiloxane content increasing. The surface hydrophobic property of cured films was improved having the water contact angles of 97° and 99° compared with 82° of the cured DOX film with only 1 wt% PSiOs, respectively. The dynamic mechanical thermal analysis results showed that both the storage modulus on the rubbery plateau region and the glass transition temperature decreased with increasing PSiO-H loading. Moreover, the decrease became more obvious as PSiO-L was added instead of PSiO-H due to its lower concentration of oxetane group. The thermal stability of cured films was enhanced by the addition of PSiOs from the thermogravimetric analysis. And the DOX/PSiO-H film possessed higher thermal degradation temperatures than DOX/PSiO-L film. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A series of benzophenone derivatives (N-BPs) containing tertiary amine group used as hydrogen abstraction-type (type II) photoinitiators were synthesized through the addition reaction of secondary amines with 4-(2,3-epoxypropyloxy) benzophenone. The chemical structures were characterized with 1H NMR, FTIR spectroscopy, and UV spectrum measurements. The N-BPs showed the higher absorption in 300-400 nm than benzophenone (BP). The photoinitiating activity was examined based on the photopolymerization of 1,6-hexanediol diacrylate using photo-DSC method. The results showed that the photoinitiating efficiency was negatively affected by the molecular structure of alkyl group connected to the tertiary amine with the order of isopropyl (N-BPI) < methyl (N-BPM) < ethyl (N-BPE) < propyl (N-BPP). Moreover, the diethanolamine-modified benzophenone derivative (N-BPOH) had the highest-photoinitiating efficiency for free radical polymerization systems among the N-BPs. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]