The X-ray powder diffraction patterns for tetramethylammonium bromide and iodide have been measured from near room temperature up to decomposition/sublimation. The unit cell parameters were refined and the coefficients of thermal expansion calculated. Unlike N(CH3)4Cl [M. Stammler, J. Inorg. Nucl. Chem. 29, 2203–2221 (1967)], N(CH3)4Br (1Br) and N(CH3)4I (1I) undergo no solid–solid transitions before decomposition/sublimation as was observed earlier by thermal analysis [S. S. Chang and E. F. Westrum, J. Chem. Phys. 36(9), 2420–2423 (1962); Coulter etal., J. Am. Chem. Soc. 62, 2845–2851 (1940); Xenopoulos etal., Mol. Cryst. Liq. Cryst. 214, 63–79 (1992)].

Protein binding studies reveal increased levels of protein adsorbed to thermally treated poly-acrylamide-modified PVDF microporous membranes in comparison to polyacrylate-modified membranes. Application of XPS, ToF-SIMS, densitometry and μthermal AFM indicate poly-acryamide-PVDF mixing as the primary cause of the increased protein binding.

Differential scanning calorimetry (DSC) was used to study blends of polystyrene (PS) and poly (p-Methylstyrene) (PpmS). The presence of two glass transitions on heating after quenching was interpreted as evidence of phase separation at the temperature of the liquid before quenching. The small difference between the glass transitions of the homopolymers in the PS/PpmS system of “13 K limits the reliable detection of double glass transitions for blends to concentrations between 30 and 70%. The results of the DSC technique are supported by comparison with small angle neutron scattering (SANS) data.

The nonequilibrium behavior of symmetrical tetra-n-alkylammonium halides is described from a study of the transition behavior using thermal analysis and hot-stage optical Microscopy. Results are discussed in terms of reversibility, supercooling, sharpness of transitions on thermal cycling, and glass transitions. The transitions of plastic to rigid crystals have the largest supercoolings. Gradual disordering on heating and incomplete ordering on cooling are found for some of the salts and represent interesting examples of order/disorder and glass transitions with reduced cooperativity.

Defects in polymers were observed by high resolution electron microscopy and inferred from their mechanical and dielectrical behavior. The details of their generation was not known, however, in the past. During the last few years we have been able to extend the molecular dynamics simulation of polyethylene to crystals containing up to 6100 atoms and to times as long as 100 ps. The major observation was that single bond rotations of more than 90° become possible already more than 100 K below the melting temperature. These defects have lifetimes of only a few ps. By coupling to kinks (2g1) they can extend their lifetime considerably. Addition of a thermal, mechanical or dielectric free energy gradient to the thermally created defects seems to be able to account for the microscopic motion needed to explain the macroscopically observed annealing, deformations and relaxation effects. Key to the mechanical and dielectric properties is thus the existence of conformational disorder (condis crystal).