A series of polypeptoid homopolymers bearing short (C1–C5) side chains of degrees of polymerization of 10–100 are studied with respect to thermal stability, glass transition and melting points. Thermogravimetric analysis of polypeptoids suggests stability to >200 °C. The study of the glass transition temperatures by differential scanning calorimetry revealed two dependencies. On the one hand an...

Effects of thermal transitions (glass transition, crystallization), water, and glycerol on invertase activity in freeze-dried carbohydrate systems were investigated. Efficacy of κ-carrageenan to delay sugar crystallization in freeze-dried carbohydrate systems was also studied. Water sorption properties and glass transition temperatures, Tg, were determined for freeze-dried carbohydrate-sucrose ...

Poly(acrylic acid) + zinc diacetate hybrid composites have been prepared by precipitation from aqueous solutions and drying. The lowest glass transition temperature Tg determined by differential scanning calorimetry (DSC) is 392°C, providing a service temperature range unusually large for polymer-based materials (PBMs). Thermogravimetric analysis (TGA) shows that thermal decomposition begins so...

High molecular weight nano/micron sized polystyrene (Mv=1X10) was prepared from styrene and hydrogen peroxide over a range of temperature, shear rate and concentration of catalysts. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements indicated that the size of particles matched with that of the single polymer chain. The same ...

The dynamics of supercooled ortho-terphenyl has been studied using photon-correlation spectroscopy (PCS) in the depolarized scattering geometry. The obtained relaxation curves are analyzed according to the mode-coupling theory (MCT) for supercooled liquids. The main results are: i) the observation of the secondary Johari-Goldstein relaxation (β) that has its onset just at the dynamical crossove...

We have studied critical phenomena of spin glass transition for larger Dzyaloshinsky-Moriya anisotropy Heisenberg spin glass system, PtMn. The analysis of nonlinear magnetizations in the framework of the existence of a phase transition at Tg yields the critical exponents  = 2.5 ± 0.3,  = 1.5 ± 0.3 and  = 1 ± 0.3. These results suggest that the universality class of spin glass transition on P...

The reorientational dynamics within the rotationally disordered cubic plastic phase of solid ethanol is investigated by means of the concurrent use of computer molecular dynamics and quasielastic neutron scattering. Motions involving widely different time scales are shown to take place above the calorimetric ‘‘glass transition’’ which is centered at Tg'97 K. These correspond to well-defined reo...

The waiting time to form a crystal in a unit volume of homogeneous undercooled liquid exhibits a pronounced minimum τX* at a 'nose temperature' T(*) located between the glass transition temperature Tg, and the crystal melting temperature, TL. Turnbull argued that τX* should increase rapidly with the dimensionless ratio trg=Tg/TL. Angell introduced a dimensionless 'fragility parameter', m, to ch...

Dimethacrylates are known to have good photoreactivity, but their radical polymerization usually leads to irregular, highly cross-linked, and brittle polymer networks with broad thermal polymer phase transitions. Here, the synthesis of monoand difunctional β-allyl sulfones is described, and those substances are introduced as potent addition−fragmentation chain transfer (AFCT) reagents leading t...