ISO INTERNATIONAL STANDARD 15038 First edition 1999-06-01 Plastics — Organic-perester crosslinking agents for unsaturated-polyester thermosetting materials Determination of active-oxygen content Plastiques-Agentsderéticulationabasedeperestersorganiquespour materiauxthermodurcissablesabasedepolyestersnonsatures Determinationde la teneuren oxygeneactif ISO Reference number ISO15038:1999(E) Copyright International Organization for Standardizatior ed by IHS under I Not for Resale ISO15038:1999(E) Foreword ISO (the InternationalOrganizationfor Standardization)is a worldwidefederationof national standardsbodies(isO liaison with IsO, also take part in the work. isO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publicationas an International Standard requiresapproval byatleast 75%of thememberbodies castinga vote. InternationalStandardISO15038was preparedbyTechnicalCommitteeISO/TC61,Plastics,Subcommittee SC12,Thermosettingmaterials. AnnexAforms a normative part of this International Standard. @ISO1999 International Organization for Standardization Casepostale56·CH-1211Geneve20·Switzerland Internet [email protected] Printed in Switzerland tional Organization for Standardizatior ISO 15038:1999(E) INTERNATIONALSTANDARD @ISO Plastics Organic-perester crosslinking agents for unsaturated-polyester thermosetting materials Determination of active-oxygen content WARNING - This International Standard involves the handling of dangerous products such as peroxides The wearing of safetyglasses is therefore essential throughout the test. 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. Table1-Maintypesoforganicperester 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 alonecan thenbeobtained by subtraction. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard.For dated references, subsequent amendments to, or revisions of, any of these undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currentlyvalid International Standards. ISO385-1:1984,LaboratoryglasswareBurettes—Part1:General requirements. ISO648:1977,Laboratoryglassware- One-markpipettes. IsO3696:1987,Waterforanalyticallaboratoryuse-Specificationandtestmethods. Copyright Intern national Organization for Standardizatior 1