BS ISO 15038:1999

Plastics. Organic-perester crosslinking agents for unsaturated-polyester thermosetting materials. Determination of active-oxygen content. | Status: Confirmed, Current

1 Scope This International Standard specifies a method of determining the total active-oxygen content of organic peresters. It applies to those peresters used to initiate crosslinking of unsaturated-polyester thermosets. The peresters most widely used in the crosslinking of unsaturated-polyester resins are given in Table 1. Table 1 — Main types of organic perester Perester Molecular mass tert-Butyl perbenzoate 194,2 tert-Butyl 2-ethylperhexanoate 216,3 iso-Propyl tert-butylperoxy carbonate 176,2 tert-Amyl 2-ethylperhexanoate 230,3 tert-Amyl perbenzoate 208,3 tert-Butyl 3,5,5-trimethylperhexanoate 230,4 Butyl peresters may contain traces of tert-butyl hydroperoxide (TBHP), the active oxygen in which can be determined separately from that in the perester itself (see annex A). The active-oxygen content of the perester alone can then be obtained by subtraction.