Study on Initiation Mechanisms of Peresters Using α-Methylstyrene Dimer (MSD) Trapping Technique

Effect of type of peroxide on cross-linking of poly(l-lactide)

“…In the explanation shown in Scheme 1, LPO and BPO gave rise to lauroyloxy (ILa) and benzoyloxy radicals (IBa), respectively. In the MSD trapping technique [22], ILa was converted to undecyl radicals (ILb) by releasing CO 2 , while 30% of IBa were converted to phenyl radicals (IBb) at 140 C. Furthermore, a marked cage effect resulted in recombination of ILb radicals caused a lower f ((1), while IBa and IBb had a higher f (z1) because of a less pronounced cage effect [22].…”

“…Furthermore, a more pronounced cage effect [22] resulted in the recombination of IITd radicals and a lower f ((1) gave rise to t-butoxy 2,2,4-trimethylpentane. TBPB induced greater cross-linking in PLLA than did TBEC, even though their respective primary radicals (IIBa and IIEa) were not affected by the cage effect or by decarboxylation [22,23]. This was because the higher hydrogen abstraction ability of IIBa caused more extensive cross-linking than did IIEa.…”

The Chemistry of Peresters

“…As radical decarboxylation is not readily accessible, radical‐radical recombination in the cage is more common. Peresters of aromatic acids undergo decarboxylation at a much lower rate and tend to more efficient radical initiators because of this , …”

Pursuing high efficiency in photocatalytic oxidative couplings of heteroarenes and aliphatic C–H bonds

“…26 β scission of t -butoxy radical to produce acetone and methyl radical is a minor process. 27 On a productive pathway (Fig. 4b), cyclohexyl radical added to the C2 position of isoquinoline, and the resulting radical adduct underwent hydrogen abstraction by t -butoxy radical or benzoyl radical to release final product 2a .…”