Glass, generally state

Bis( 1,2-dithiolene) complexes are generally thermally and photochemically very stable, and their Vis-NIR absorption can be tuned in order to reach the wavelength ranges of interest for NIR lasers, such as Nd YAG, Nd YLF, and Er Glass solid-state lasers (emission wavelengths A.em = 1064, 1053, and 1540 nm, respectively). In this context, many groups of researchers have devoted their efforts to synthesising 1,2-dithiolene complexes for this type of application, and indeed some of them have been patented and are commercially... 

In many cases the relaxation of the magnetization is found to depend exponentially on the barrier but the pre-exponential factor tq was orders of magnitude shorter than observed in SMM. This behaviour is generally attributed to a transition to a spin glass-like state, SGL. 

This type of adhesive is generally useful in the temperature range where the material is either leathery or mbbery, ie, between the glass-transition temperature and the melt temperature. Hot-melt adhesives are based on thermoplastic polymers that may be compounded or uncompounded ethylene—vinyl acetate copolymers, paraffin waxes, polypropylene, phenoxy resins, styrene—butadiene copolymers, ethylene—ethyl acrylate copolymers, and low, and low density polypropylene are used in the compounded state polyesters, polyamides, and polyurethanes are used in the mosdy uncompounded state. 

As appHed to hydrocarbon resins, dsc is mainly used for the determination of glass-transition temperatures (7p. Information can also be gained as to the physical state of a material, ie, amorphous vs crystalline. As a general rule of thumb, the T of a hydrocarbon resin is approximately 50°C below the softening point. Oxidative induction times, which are also deterrnined by dsc, are used to predict the relative oxidative stabiHty of a hydrocarbon resin. 

Fig. 19. Generalized modulus—temperature curves for polymeric materials showing the high modulus glassy state, glass-transition regions for cured and uncured polymers, plateau regions for cross-linked polymers, and the dropoff in modulus for a linear polymer.

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