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Thermally processed material is usually totally amorphous, [7] and as a result is highly transparent to visible light, with better light transmission than many kinds of glass. Polycarbonate has a glass transition temperature of about 147 °C (297 °F), [8] so it softens gradually above this point and flows above about 155 °C (311 °F). [9]
Low molecular weight PTMC is a rubbery polymer with poor dimensional stability, tackiness, and inadequate mechanical properties. Nevertheless, high molecular weight amorphous PTMC (over 100,000) is very flexible, with a relatively low elastic modulus (5–7 MPa) at room temperature, tough and it presents excellent ultimate mechanical properties.
A material property is an intensive property of a material, i.e., a physical property or chemical property that does not depend on the amount of the material. These quantitative properties may be used as a metric by which the benefits of one material versus another can be compared, thereby aiding in materials selection.
As done in crystalline materials, particles can be added to semi-crystalline polymers to change the mechanical properties. In crystalline materials the addition of particles works to impede dislocation motion and strengthen the material. However, for many semi-crystalline polymers particle fillers weaken the material.
During the process of the UL 746B program, the degradation in hot air of certain properties of the material like dielectric and mechanic strength, is investigated with regards to thermal-aging. For a full study, the candidate material (B) is aged together with a reference material A (control) with already known RTI value in the same ovens.
In both cases, the matrix and fibers have complimentary mechanical properties and the resulting composite material is therefore more practical for applications in the real world. For a composite containing aligned, stiff fibers which span the length of the material and a soft, ductile matrix, the following descriptions provide a rough model.
Also mechanical properties are closely linked to the thermal stability. Based on the properties of the standard plastics some improvements of mechanical and thermal features can already be accomplished by addition of stabilizers or reinforcing materials ( glass and carbon fibers , for example) or by an increase in the degree of polymerization .
The strength of materials is determined using various methods of calculating the stresses and strains in structural members, such as beams, columns, and shafts. The methods employed to predict the response of a structure under loading and its susceptibility to various failure modes takes into account the properties of the materials such as its yield strength, ultimate strength, Young's modulus ...