Crystallinity glass transition

The physical properties (7-10) of our E-V copolymers are sensitive to their microstructures. Both solution (Kerr effect or electrical birefringence) and solid-state (crystallinity, glass-transitions, blend compatibility, etc.) properties depend on the detailed microstructures of E-V copolymers, such as comonomer and stereosequence distribution. I3C NMR analysis (2) of E-V copolymers yields microstructural information up to and including the comonomer triad level. However, properties such as crystallinity depend on E-V microstructure on a scale larger than comonomer triads. 

Table 5.5. Composition, pretreatment, crystallinity, glass transition temperature Tg and experimental and calculated microhardness values, Hg p, and Hgai and their difference AH = Hgai — Hg p for thermoplastic elastomers of PEE-or PEEC-type. 

The chain-end functionalized polymer is a very attractive material that possesses an unperturbed polymer chain with desirable physical properties (such as melting temperature, crystallinity, glass transition temperature, melt flow, etc.) that are almost the same as those of the pure polymer. Nevertheless, the terminal reactive group at the polymer chain end has good mobility and can provide a reactive site for many applications. This includes adhesion to the substrates, reactive blending, and formation of block copolymers. 

DSC (solid state) Crystallinity, glass transition A must-have for lyophilized products... 

Appearance Melting temperature (°C) Density (g/cc) Tensile strength [psi (N/m )l Solubility Crystallinity (%) Glass transition temperature (°C) Hard solid 175 0.90-0.92 5,000 (3.4X10 ) Insoluble in most organic solvents <70 0 to —35 Hard solid 131 0.89-0.91 Soluble in ether and aliphatic hydrocarbon Soft rubbery <100 0.86-0.89 Soluble in common organic solvents -11 to -35... 

Similar procedures have been used by several workers (Halasa et al., 1982) to hydrogenate poly(l,4-butadiene-co-1,2-butadiene) diblocks (Halasa, 1985) and poly(l,4-butadiene-co-l,4-isoprene-co-1,4-butadiene) triblocks. Hydrogenation of these diblock and triblock copolymers forms thermoplastic elastomers with crystalline and amorphous segments. All these materials exhibit crystallinity, glass transition, solubility, and dynamic mechanical loss spectra different from those of their unsaturated counterparts. 

The kinetics of migration of additives from the package into the (food) contents depends on the characteristics of the plastics such as density or free volume, crystallinity, glass transition temperature (Tg), as well as the polarity, molecular mass, and boiling point of the migrant species. Migration rates also depend on the temperature, relative humidity, pH value, and the composition of the food contents (Sajilata et al., 2007). Given the number of variables that can affect the results, reported data must be compared cautiously. 

Percent crystallinity, glass transition and melting temperatures of polymers... 

The general characteristics that control a polymer s behavior are basic chemical composition, crystallinity, glass transition temperature, molecular weight and distribution, gel and crossbnking. Some ways in which desired properties can be achieved are shown in Tab. 2-3. Of course this Table only shows a few possibibties in polymer... 

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