Search results
Results from the WOW.Com Content Network
The Flory–Fox equation relates the number-average molecular weight, M n, to the glass transition temperature, T g, as shown below: =, where T g,∞ is the maximum glass transition temperature that can be achieved at a theoretical infinite molecular weight and K is an empirical parameter that is related to the free volume present in the polymer sample.
Therefore, this polymer relies solely on physical anchor points. When heated up to Tg, the material abruptly changes from a rigid state to a tapered state (softens). To achieve the effect, the shape must be changed rapidly to avoid rearrangement of the segments of the polymer chains and immediately cool the material also very rapidly below Tg.
The phase behavior of polymer solutions is an important property involved in the development and design of most polymer-related processes. Partially miscible polymer solutions often exhibit two solubility boundaries, the upper critical solution temperature (UCST) and the LCST, both of which depend on the molar mass and the pressure. At ...
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. [2]
As the polymer is sensitive to both chlorine and acid hydrolysis, it may perform very poorly when exposed to the reactive gases, particularly hydrogen chloride (HCl). Failures in this latter instance can occur with seemingly unimportant exposures from well sealed joints and do so without warning and rapidly (the component will split or fall apart).
It is a synthetic acrylate polymer derived from butyl acrylate monomer. The polymers are colorless. This homopolymer is far less important than copolymers derived from methyl acrylate and other monomers. It has a low glass-transition temperature of about -43 °C (20 °C). [clarification needed]
Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges between 10 and 80%, with crystallized polymers often called "semi-crystalline". The properties of semi-crystalline polymers are determined not only by the ...
The PPE blends are characterized by hot water resistance with low water absorption, high impact strength, halogen-free fire protection and low density. This plastic is processed by injection molding or extrusion; depending on the type, the processing temperature is 260–300 °C. The surface can be printed, hot-stamped, painted or metallized.