Activity coefficients of solvents in elastomers measured with a quartz crystal microbalance

Vapour sorption studies of polymer‐solution thermodynamics using a piezoelectric quartz crystal microbalance

“…Wong and co‐workers14 applied this technique to the sorption of three solvents by polystyrene and found that accurate results could be obtained rapidly. Activity coefficients of solvents in a series of elastomeric polymers were measured by French and Koplos15 who found reasonable agreement with some literature systems.…”

“…In view of the widespread use of PMMA, there is a surprising dearth of information available on its solution thermodynamics 1, 29, 34. As with P4ClS, mixtures of 2‐butanone and 2‐propanol are used in industrial coating and developing systems.…”

“…The relatively thin films also mean that measurements can be made more quickly. Although not exploited here, a very wide range of conditions such as temperature and pressure can be used 34…”

Polymer modification using difluoromethane (HFC 32) and carbon dioxide

“…Only a few data points were acquired for the PS system because as the pressure was increased the QCM signal response was lost. This signal dampening is due to a significant increase in mass on the surface of the quartz crystal of the QCM due to sorption of gas within the PS sample 36. A more informative interpretation of the acquired data can be obtained by calculating the reduction in T g due to gas‐induced plasticization.…”

Πειραματική Και Θεωρητική Μελέτη Πολυσύνθετων Συστημάτων Αερίων-Πολυμερών Σε Ισορροπία

“…όπου ρ f η πυκνότητα του υγρού και n f το ιξώδες του για την περίπτωση απείρως εκτεινόμενου υγρού φιλμ, δηλαδή για την περίπτωση που το πάχος του φιλμ είναι πολύ μεγαλύτερο από το μήκος απόσβεσης του εγκάρσιου κύματος μέσα στο ρευστό. Το μήκος αυτό δίνεται από την εξής σχέση: λιγότερος χρόνος) από τις κλασικές μετρήσεις βάρους [French 1999]. Eπίσης, οι ηλεκτρονικές συσκευές μέτρησης της συχνότητας που χρησιμοποιούνται δίνουν αποτελέσματα με πολύ μεγάλη ακρίβεια, της τάξης του 1 Ηz, που αντιστοιχούν σε ακρίβεια ng για τις μετρήσεις μάζας [Sugimoto 1999].…”