Polybutylene terephthalate (PBT) is a polyester and has properties similar to that of polyethylene terephthalate (PET, see page 112). It is, however, better suited for injection molding due to its cooling and processing behavior.
|DSC 204 F1 Phoenix®
|3 min/ / 3 min / 5 min
|Al, pierced lid
|N2 (50 ml/min)
A Temperatura di transizione vetrosaLa transizione vetrosa è una delle più importanti proprietà chimico-fisiche dei materiali amorfi e semi-cristallini, come, ad esempio, vetri, metalli (amorfi), polimeri, ingredienti farmaceutici e alimentari e definisce l’intervallo di temperatura in cui le proprietà meccaniche die materiali variano da duro e fragile a più morbido, malleabile o gommoso.glass transition (here at 42°C, midpoint) and a clearly structured endothermal melting effect for the α (peak temperature 226°C) and β phase (peak temperature 217°C) in the 2nd heating (red) are characteristic of PBT. In the 1st heating (blue), the glass transition midpoint temperature of 44°C was comparable to that in the 2nd heating, but is overlapped with a RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation peak. Prior to the melting transition, a Post Crystallization (Cold Crystallization)The post crystallization of semi-crystalline plastics occurs primarily at elevated temperatures and increased molecular mobility above the glass transition.post crystallization (small EsotermicoUna transizione o reazione è esotermica se il materiale genera calore exothermal peak at 207°C) occurred in the 1st heating.