This International Standard specifies three methods for evaluating the melting behaviour of semi-crystalline polymers.
Section one specifies a capillary tube method (method A), which is based on the changes in shape of the polymer. This method is applicable to all polymers and their compounds, even if there is no crystalline phase.
Section two specifies a polarizing microscope method (method B), which is based on changes in the optical proper-ties of the polymer.
This method is applicable to polymers containing a birefringent crystalline phase; it may not be suitable for plastics compounds containing pigments and/or other additives which could interfere with the birefringence of the polymeric crystalline zone.
Section three specifies a thermal analytical method (method C), having two variants :
— method C1, which uses Differential Thermal Analysis (DTA);
— method C2, which uses Differential Scanning Calorimetry (DSC).
Both are applicable to all polymers containing a crystalline phase and their compounds.
The melting temperatures determined by the different methods usually differ by several kelvins for the reasons explained in the Introduction.
Of the methods given above, experiments have indicated DSC (Differential Scanning Calorimetry) to be the method of choice as having the best reproducibility of results.
SIS SS-ISO 3146:1987 history
1987SIS SS-ISO 3146:1987 Plastics - Determination of the melting behaviour (melting tern perature or melting range) of semi-crystalline polymers