BS ISO 22768:2017 pdf download – Rubber, raw — Determination of the glass transition temperature by differential scanning calorimetry (DSC) 1 Scope This document specifies a method using a differential scanning calorimeter to determine the glass transition temperature of raw rubber. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1407, Rubber — Determination of solvent extract ISO 11357-1:2016, Plastics — Differential scanning calorimetry (DSC) — Part 1: General principles ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 11357-1 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http:// www .electropedia .org/ — ISO Online browsing platform: available at http:// www .iso .org/ obp 3.1 glass transition reversible change in an amorphous polymer, or in amorphous regions of a partially crystalline polymer,from (or to) a rubbery or viscous condition to (or from) a glassy or hard condition 3.2 glass transition temperature T g approximate midpoint of the temperature range over which the glass transition (3.1) takes place Note 1 to entry: For the purposes of this document, the glass transition temperature is defined as the point of inflection of the DSC curve which has been obtained at a heating rate of 20 °C/min (see A.3). 4 Principle The change in specific heat capacity of the rubber as a function of temperature under a specified inert atmosphere is measured using a differential scanning calorimeter (DSC). The glass transition temperature is determined from the curve thus produced. 5 Apparatus and materials 5.1 Differential scanning calorimeter, in accordance with ISO 11357-1:2016, 5.1. The calorimeter should be operated in a room held at standard laboratory temperature. It should be protected from draughts, direct sunlight and sudden temperature changes. 5.2 Specimen pans (crucibles), in accordance with ISO 11357-1:2016, 5.2. 5.3 Gas supply, analytical grade, usually nitrogen or helium. 5.4 Balance, capable of measuring the specimen mass to an accuracy of ±0,000 1 g. 6 Test specimen The test specimen shall be as representative as...
Download Address
Download