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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]
A polycarbonate is an oxocarbon dianion consisting of a chain of carbonate units, where successive carbonyl groups are directly linked to each other by shared additional oxygen atoms. That is, they are the conjugate bases of polycarbonic acids , the conceptual anhydrides of carbonic acid , or polymers of carbon dioxide .
Although single layer polycarbonate sheeting is more flexible than polycarbonate in twinwall configuration, it still retains significant advantages over alternative materials, including glass. A typical 6mm sheet has a density of 0.72 g/cm^2 [ 6 ] and a thermal insulation R value of 0.3 m^2°C/W, while allowing 80% of visible light pass through ...
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. The RTI is the rounded temperature in degrees C , at which the properties of B have decreased to 50 percent of their initial value in about the same amount of time (correlation time) than it takes ...
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.
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.
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.
The currently most-consumed engineering plastic is acrylonitrile butadiene styrene (ABS), used for e.g. car bumpers, dashboard trim and Lego bricks. Engineering plastics have gradually replaced traditional engineering materials such as metal, glass or ceramics in many applications. Besides equalling or surpassing them in strength, weight, and ...