Rationalisation of Vicat softening point measurements

• Published in: Polymer testing Vol. 9; no. 2; pp. 75 - 89
• Main Authors: Namhata, S.P., Santolini, L., Locati, G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1990; Elsevier
• Subjects: Applied sciences; Exact sciences and technology; Mechanical properties; Physical properties; Polymer industry, paints, wood; Properties and testing; Technology of polymers; Ethylene terephthalate polymer; Thermal properties; Amide 6 polymer; Vicat needle test; Mechanical properties; Mineral fiber; Glass fiber; Polycarbonate; Mixture
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/0142-9418(90)90021-5

The utility of the Vicat softening point is rationalised one step further. Light is thrown on Vicat measurements and they are interpreted from a qualitative viewpoint; it is stated that the Vicat softening point is nothing but a temperature at which the modulus has reached a particular level. So the Vicat softening point is not just an arbitrary point measurement but a well-defined point in the modulus-temperature diagram, being related to the fundamental properties of the material. This interpretation enables one to understand and control the thermal behavior of polymers, especially in developments of new blends where a target Vicat softening point is often pre-specified. The validity of the above statement is esablished through experimental work. The quantitative values of modulus levels related to different Vicat measurements (Vicat A and B) are estimated. The Vicat values generally supplied in material literature can now be used for design purposes and for other critical structural calculations which are nowadays a common practice for the plastics designers.