A measuring system for bulk and shear characterization of polymers

• Published in: Experimental mechanics 2006-08, Vol.46 (4), p.429-439
• Main Authors: EMRI, I, PRODAN, T
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Injection moulding; Machinery and processing; Measurement and testing methods; Moulding; Physics; Plastics; Polymer industry, paints, wood; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Technology of polymers
• ISSN: 0014-4851; 1741-2765
• DOI: 10.1007/s11340-006-8528-4

This paper describes a novel measuring system for investigating the influence of pressure and temperature on the mechanical properties of time-dependent polymer materials. The system can measure the volume and the shear relaxation moduli of solid polymer specimens simultaneously subjected to temperatures from -50 to +120 deg C with a precision of +/-0.01 deg C, and pressures from atmospheric to 500 MPa with a precision of +/-0.1 MPa. The paper demonstrates the measuring capabilities of the apparatus. For poly(vinyl) acetate (PVAc) are presented sample measurements of the shear relaxation modulus as function of time, pressure and temperature; specific volume; the bulk creep compliance; the coefficient of thermal expansion; the bulk modulus; and the pressure drop experiments which simulate conditions to which a material is exposed during the injection molding process. The shear moduli may be measured in the range from 1 to 4,000 MPa with the relative error of 3%.The error of volumetric measurements is 0.05%, which corresponds to 0.00005 cm/g. In all cases results are shown as measured, no additional smoothing or filtering was employed.