title: Dual beam differential photopyroelectric setup for broadband thermal effusivity investigation of glass transitions in polymers.
abstract: The behaviour of the thermal effusivity squared over the glass transition in polystyrene is measured over a considerable frequency range using a novel dual beam front detection photopyroelectric configuration, which ensures a very effective processing of the obtained signal. This has enabled the detection of the very small changes taking place in such a parameter, despite the non-favourable sensitivity conditions due to the large mismatch between the thermal effusivities of the pyroelectric transducer and of the sample. The effect of the thermal contact resistance between the sample and the pyroelectric detector is also considered and discussed.
authors.affiliation: Dipartimento di Ingegneria Industriale, Università di Roma Tor Vergata, Rome I-00133, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Paoloni
authors.forename: U
authors.initials: U
authors.lastname: Zammit
authors.forename: M
authors.initials: M
authors.lastname: Marinelli
authors.forename: F
authors.initials: F
authors.lastname: Mercuri
authors.forename: R
authors.initials: R
authors.lastname: Pizzoferrato