determination of temperature and enthalpy of melting-crystallisation
thermal analysis – determination of temperature and enthalpy of melting-crystallisation
determination of temperature and enthalpy of melting-crystallisation
Semi-crystalline plastics, when heated, pass from the crystalline (solid) stage to the molten (soft) phase. Due to their different molecular structures, plastics melt at different temperatures. The most precise method to determine the melting properties of the plastics is by differential scanning calorimetry (ISO 11357-3, ASTM D3418).
A small piece of plastic (approximately 10 mg) is heated and cooled at a control rate under nitrogen. During the heating and the cooling cycles, the following parameters are obtained:
- melting of semi-crystalline plastics: transition stage between a fully crystalline or partially crystalline solid state and an amorphous liquid of variable viscosity
- crystallisation: transition stage between an amorphous liquid state and a fully crystalline or partially crystalline solid state
- enthalpy of fusion: heat required to melt a material at constant pressure
- enthalpy of crystallisation: heat released by the crystallisation of a material at constant pressure
why impact?
Some members of impact’s team have over 30 years of polymer experience, with over 120 years combined, and are internationally regarded as product experts including sitting on various CEN committees and being a notified body for construction products (Note because of our notified body status we cannot undertake consultancy on oil storage tanks), we can often identify potential sources of weakness in products without even undertaken testing using our experience.
Find out more about our experts here, or visit our about page. Alternatively you can get in touch with one of our experts for more information.
