ISO INTERNATIONAL STANDARD 8987 Third edition 2005-10-01 Plastics Phenolic resins Determination of reactivity ona B-transformation test plate Plastiques-Résinesphénoliques-Methodesd'évaluationdela reactivite surplaqued'essaidetransformation austadeB Reference number ISO 8987:2005(E) ii Foreword IsO (the International Organization for Standardization)is a worldwide federation of national standards bodies (iSO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been InternationalElectrotechnicalCommission(lEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75%ofthe member bodies casting a vote Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 8987 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 12, Thermosetting materials. This third edition cancels and replaces the second edition (IsO 8987:1995), which had been revised to allow the temperature of the test plate to be controlled by melting salts. ii blank Plastics Phenolic resins Determination of reactivity onaB-transformationtestplate 1 Scope resins at a specified temperature and under specified conditions on a heated test plate. Two methods are described, each with a different test plate: Method A -plate with depressions in the form of segments of spheres; Method B flat plate without depressions. 2 Principle The condensation of the phenolic resin is carried out to the B-stage on one of two types of test plate, depending on the method. Method A:Determination on a plate withdepressions 3.1Apparatus 3.1.1 Thermostatic control device,permissibletemperaturevariation±O,5C. 3.1.2 Hotplate, on which the test plate can be fixed in a suitable manner to obtain optimum heat transfer NOTE No hotplate is necessary if a test plate with an integral heater is used. 3.1.3 Glass rod, 5 mm in diameter, tapering to about 2 mm in diameter at one end. 3.1.4 Balance, scale interval 0,01 g. 3.1.5 Syringe. 3.1.6 Stopwatch, with at least 1 s sub-divisions. 3.1.7 B-transformation test plate, with depressions as shown in Figure 1, with or without an integral heater. Suitable melting salts may be used for accurate control of the heater. 3.2Number of tests Conduct one or more tests, depending on the requirements of the appropriate International Standard or as agreed between the parties concerned. Dimensions in millimetres $200 Key holefortemperature sensorof thermostatic control device hole for thermometer stem 2 3 protective metal tube forthermometer Figure1—B-transformationtestplate 3.3Procedure Bring the B-transformation test plate (3.1.7) to the required temperature and place a box, open on top, round the test plate to provide protection against draughts. Pour (0,5 ± 0,o5) g of phenolic resin into one of the depressions inthetestplate andstartthe stop watch (3.1.6)whentheresintouches theplate.Liguid resinsor phenolic resin solutions may be placed in the depression with a syringe (3.1.5). Stir the resin with the glass rod (3.1.3), using short circular movements from the edge of the depression towards the middle. For longer B-transformation times, stir initially for one minute and then at one-minute intervals for 10 s. If the time,to give an accurate determination. Towards the end of the test, when the resin becomes viscous, stir continuously. Briefly raise the rod and observe if the resin is drawn out in a thread. The B-trans