Trialkyl phosphites and diaryliodonium salts as co-initiators in a system for radical-promoted visible-light-induced cationic polymerization.

Trialkyl phosphites ((RO)3P) can act as co-initiators for the diaryliodonium-induced cationic polymerization of cyclohexene oxide (CHO) or THF. A radical initiation step is also required, consistent with the essential role of a radical chain reaction of the phosphite with the iodonium salt to form polymerization-starting aryltrialkoxyphosphonium salts (ArP(+)(OR)3). We used the visible photolysis of phenylazoisobutyronitrile (PAIBN) as the radical initiation step.

Product channels of the HCCO + NO reaction.

The product branching ratio of the HCCO + NO reaction was investigated using the laser photolysis/infrared absorption technique. Ethyl ethynyl ether (C(2)H(5)OCCH) was used as the HCCO radical precursor. Transient infrared detection of CO, CO(2), and HCNO products was used to determine the following branching ratios at 296 K: phi(CO+HCNO) = 0.

Kinetics of the HCCO + NO2 reaction.

The kinetics of the HCCO + NO2 reaction were investigated using a laser photolysis/infrared diode laser absorption technique. Ethyl ethynyl ether (C2H5OCCH) was used as the HCCO radical precursor. Transient infrared detection of the HCCO radical was used to determine a total rate constant fit to the following expression: k1= (2.

Kinetics of the OH + HCNO reaction.

The kinetics of the OH + HCNO reaction was studied. The total rate constant was measured by LIF detection of OH using two different OH precursors, both of which gave identical results. We obtain k = (2.