The spiro‐orthoester, cis‐2,3‐tetramethylene‐1,4,6‐trioxaspiro[4,4]nonane (cis‐TTN) (I), underwent rapid cationic photopolymerization when exposed to UV light using diphenyliodonium salts as a photoinitiator. The polymer, poly[(trans‐OCB)x′‐(cis‐OCB)x″‐(CHO)y] thus formed consisted of poly(trans‐2‐oxycyclohexyl butanoate) (trans‐OCB)x′ (II), poly(cis‐2‐oxycyclohexyl butanoate) (cis‐OCB)x″ (III), and poly‐ (1,2‐cyclohexene oxide) (CHO)y segments, and no expected pure poly(ether‐ester), that is, poly(2‐oxycyclohexyl butanoate), was isolated. The structure of the polymer was identified, and the mechanism of the reaction was deduced. The polymer thus formed exhibited expansion in volume during cationic photopolymerization when compared to that obtained by conventional cationic polymerization using a Lewis acid (e.g., BF3OEt2, CH3OSO2CF3, or SnCl4) as an initiator, which demonstrated volume shrinkage during polymerization. The volume expansion of the polymer during polymerization was due to (1) the lower content of the higher density (CHO)y segment in the polymer chain and, more importantly, (2) the higher and optimal mole ratio of (trans‐OCB)x′ and (cis‐OCB)x″ segments that led the polymer in a more disordered, less dense, and higher volumetric state. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3680–3690, 2009

A stereoregular poly(ether ester), poly(trans-2-oxycyclohexyl butanoate) (-[trans-2-OCHB] n -) (II), was obtained by cationic polymerization of cis-2, 3-tetramethylene-1,4,6-trioxaspiro[4,4]nonane (I) initiated by the 9-phenyl-9,10-dihydroanthracen-10-ylium cation (PDAC) obtained by exposing a mixture of (4-octylphenyl)phenyliodonium hexafluoroantimonate (OPIA) and anthracene (A) to UV light at 254 nm. The structure of II, the polymerization mechanism of I, and the relationship between volume changes during polymerization and polymer structure were studied. The polymerization mechanism of I proceeded in a regiospecific manner and was determined in terms of the relation among the polymer structure, the steric hindrance sensitized PDAC, and the only intermediate, 1,3-dioxolan-2-ylium carbocation (DOLC). Polymer II exhibited high volume expansion (2.09 ( 0.25%) during polymerization compared to that of -[cis-2-OCHB] n -(III), obtained by polymerization of I using SnCl 4 as an initiator, which demonstrated high volume shrinkage (-2.49 ( 0.13%) during polymerization. The volume expansion of II is caused by the conversion of cis substitution at C-2 and C-3 in I to the trans form during polymerization.

ABSTRACT:The surface-modified diamond and PET film underwent photopolymerization rapidly with a binder agent to afford coating films of interpenetrating network (IPN) structure. The coating films thus formed exhibit higher tensile strength, thermal stability, and adhesion strength to the PET film. The inert surfaces of pristine diamond (PD) and PET film were modified by different chemicals and procedures to introduce epoxide and methacryloyl groups, respectively, on their surfaces. A coating agent consisting of an epoxide group containing modified diamond (called ED), a binder agent, and photoinitiators was prepared. After applying the coating agent to the substrate (a glass plate or a methacryloyl group containing PET film, MMA-PET) and degassing under reduced pressure, the thin film of the coating agent was exposed to UV light (k max ; 365 nm) at room temperature to yield a coating film of IPN-structure. The tensile strength and thermal properties of the ED-containing free coating film (called free film) increased with the amount of ED embedded, whereas the strength of the PD-containing free film decreased with the amount of PD embedded. The adhesion strength of the coating film on the MMA-PET improved significantly by the free radical polymerization of the methacryloyl groups on the MMA-PET and the acrylate resin in the binder agent. The surface photoreactions of ED and MMA-PET with the binder agent were confirmed by modeling.