initially cleaves at the oxygen-oxygen bond; other bond cleavages can and do occur either simultaneously with or sequencers to the oxygen-oxygen bond dissociation.
An alternative cure procedure was also studied, using dibenzoyl peroxide
as curing initiator.
3-Amino acetophenone (E-Merck), boron trifluoride ([BF.sub.3]) (50% w in ether) (E-Merck), dibenzoyl peroxide
(Fluka) and dimetoxyethane (Fluka) were obtained in an analytical grade and used as supplied.
(a) Chemical name Abridged name Formula [M.sub.w] (kg/mol) dicumyl peroxide DCP [??] 270 di-4-tert-butylcyclohexyl peroxide BCHPC [??] 398 di-tert-butyl peroxide DTBP [??] 146 cumene hydroperoxide CHP [??] 152 dibenzoyl peroxide
BPO [??] 242 Chemical name [MATHEMATICAL [E.sub.A] EXPRESSION NOT ([kJ/mol]) REPRODUCIBLE IN ASCII] ([degrees]C) dicumyl peroxide 132 129.3 di-4-tert-butylcyclohexyl peroxide 64 128.1 di-tert-butyl peroxide 141 130.7 cumene hydroperoxide 166 132.5 dibenzoyl peroxide
91 122.3 (a) [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] ([degrees]C) represents the temperature at which the half-life time of peroxide is hour.
To achieve the titration and determine the time of reaction leading to the total decomposition of peroxide groups onto ozonized PE, we used dibenzoyl peroxide
since it possesses a similar half lifetime ([t.sub.1/2] = 28 min at 100[degrees]C) in comparison with those of peroxide species coming from ozonized PE (8) ([t.sub.1/2] = 5 mm at 100[degrees]C).
Dicumyl peroxide (DCP) 98% and dibenzoyl peroxide
(DBP) 70% from Aldrich Chemical Company were used as purchased.