Search results for "Polymer solidification"
showing 3 items of 3 documents
Structure and Morphology Control in Polymer Forming Through the Thermal History
2011
Two examples of the application of the Continuous Cooling Transformation (CCT) method for investigating polymer solidification under processing conditions are illustrated. One example concerns the solidification behaviour of syndiotactic polystyrene (sPS) from the melt, showing an anomalous trend of density versus cooling rate, exhibiting a minimum around 1 °C/s. Once phase composition is obtained from WAXD deconvolution, density can be closely predicted, its minimum depending on the competition among crystalline phases upon increasing cooling rate. Another example regards the formation of Poly-Left Lactic Acid (PLLA) foams via Thermally Induced Phase Separation (TIPS) by starting from ther…
Polymer Solidification under Pressure and High Cooling Rates
2000
Abstract Polymer solidification under processing conditions is a complex phenomenon in which the kinetics of flow, high thermal gradients and high pressures determine the product morphology. The study of polymer structure formed under pressure has been mainly made using conventional techniques such as dilatometry and differential scanning calorimetry under isothermal conditions or non isothermal conditions but at cooling rates several orders of magnitude lower than those experienced in industrial processes. A new equipment has been recently developed and improved to study the crystallization of polypropylene when subjected to pressure and cooled rapidly. An experimental apparatus essentiall…
The solidification behavior of a PBT/PET blend over a wide range of cooling rate
2009
In recent years, much attention has been paid to the development of high-performance polyester blends, among which blends of polybutylene terephtha- late/polyethylene terephthalate (PBT/PET) are expected to exhibit remarkable prop- erties as far as their crystallization behavior is concerned. Through trial and error, appropriate commercial compositions have been chosen which could not be otherwise explained by a suitable interpretation of the mechanisms determining their solidifica- tion behavior. The solidification behavior of a 60/40 w/w PBT/PET blend was studied in a wide range of cooling conditions, according to a continuous cooling transforma- tion (CCT) procedure developed previously,…