extensively used in biomedical applications. In this direction, poly(caprolactone) (PCL) is one of the most promising polymers, and it can be used in many medical applications, such as drug delivery, scaffolds, and guided bone regeneration [ 14 ]. PCL has been
Temperature modulated dynamic mechanical analysis (TMDMA) was performed in the same way as temperature modulated DSC (TMDSC)
measurements. As in TMDSC TMDMA allows the investigation of reversible and non-reversible phenomena during crystallisation
of polymers. The advantage of TMDMA compared to TMDSC is the high sensitivity for small and slow changes in crystallinity,
e.g. during re-crystallisation. The combination of TMDMA and TMDSC yields new information about local processes at the surface
of polymer crystallites. It is shown that during and after isothermal crystallisation the surface of the individual crystallites
is in equilibrium with the surrounding melt.
Authors:Stavroula G. Nanaki, George Z. Papageorgiou, and Dimitrios N. Bikiaris
characteristics—biodegradability, biocompatibility, and mechanical properties. Among them, polycaprolactone (PCL), polylactides, poly(hydroxy butyrate) (PHB), and poly(butylene succinate) (PBSu) are some of the most extensively used polymers of this class [ 2 , 3
TG and DTA studies on Me3SnO2PCl2, Me2Sn(O2PCl2)2 and Ph3SnO2PCl2 were carried out under dynamic argon atmosphere. The results show that the decomposition proceeds in different stages leading
to the formation of Sn3(PO4)2 as a stable product. This compound was characterized by IR spectroscopy. Decomposition schemes involving reductive elimination
reactions were proposed.
The thermoanalytical curves of (C6H5)4AsCl (I) and (C6H5)4PCl (II) were generated simultaneously by using a Netzsch simultaneous thermal analyser 409 under static air and dynamic argon
atmospheres. The ranges of thermal stability of I and II were found to be 145–310°C and 137–365°C, respectively, and their
melting points to be 261 and 278°C. The DTA profiles of I and II differ and can be used for their distinction.
Authors:C. Schick, M. Merzlyakov, A. Minakov, and A. Wurm
Quasi-isothermal temperature modulated DSC (TMDSC) were performed during crystallization to determine heat capacity as function of time and frequency. Non-reversible and reversible phenomena in the crystallization region of polymers were distinguished. TMDSC yields new information about the dynamics of local processes at the surface of polymer crystals, like reversible melting. The fraction of material involved in reversible melting, which is established during main crystallization, keeps constant during secondary crystallization for polycaprolactone (PCL). This shows that also after long crystallization times the surfaces of the individual crystallites are in equilibrium with the surrounding melt. Simply speaking, polymer crystals are living crystals. A strong frequency dependence of complex heat capacity can be observed during and after crystallization of polymers.
Authors:S. Calvo, J. Escribano, M. G. Prolongo, R. M. Masegosa, and C. Salom
about polymer blends containing one crystallizable component and a thermosetting component [ 9 ]. In previous articles, the miscibility of the systems formed by linear UP resin and poly(∊-caprolactone) (PCL) [ 10 – 13 ] were studied. For the
Authors:Christophe Block, Nick Watzeels, Hubert Rahier, Bruno Van Mele, and Guy Van Assche
Poly(∊-caprolactone) (PCL) was obtained from Solvay Caprolactones (presently Perstorp Caprolactones, UK) and is commercialized under the trade name CAPA®6500 ( M n = 47.500 g mol −1 and M w = 84.500 g mol −1 , according to the
Authors:J. Escribano, R. Masegosa, D. Nava, M. Prolongo, and Catalina Salom
The curing of the neat
unsaturated polyester resin (UP) with benzoyl peroxide (initiator) as well
as the curing of UP modified with two poly(ε-caprolactone) PCL samples
(PCL2 and PCL50) of different molecular masses (Mn=2⋅103
respectively), were investigated by non-isothermal differential scanning calorimetry
(DSC), at different heating rates. The activation energy was determined from
the variation of the peak exotherm temperature, Tpeak,
upon heating rate. Besides, the degree of conversion (α) was obtained
from isothermal DSC measurements at 80°C at different curing times for
neat UP, UP+ PCL2 and UP+PCL50. Kinetic parameters were deduced assuming the nth order reaction kinetic
model for neat UP, UP+PCL2 and UP+PCL50 systems.