Impression recovery in which the deformation temperature is the same as recovery temperature is studied for the first time. PMMA is deformed by impression above the glass transition temperature to a depth of less than 0.3 mm and recovered at the same temperature. Almost complete recovery of dimension is observed every time. The dimensional changes obey second order kinetics and the temperature dependence of the rate constant shows two consecutive processes with activation energies 440 kJ/mole (between 104 and 113 °C) and 95 kJ/mole (between 113 and 140 °C). Two pairs of defects of opposite signs are believed to be involved in the dimensional recovery processes.

Organoceramics are a new class of polymer/ceramic nanocomposite materials where polymer chains are molecularly mixed with the ceramics. A structural model for poly(vinyl alcohol) organoceramic nanocomposite materials proposed by Messersmith and Stupp [J. Mater. Res. 7, 2599–2611 (1992)] claims that polymer chains disperse in the interlayers of the ceramic precursor, causing a broadening of the basal plane spacing. The present research revealed this basal plane broadening does not exist. A new model was constructed where the polymer acts as a template for the ceramic microcrystals to nucleate and grow to reach a size of 20 Å. The ceramic microcrystals (hydrogen bonded to the polymer) further agglomerate and grow to the resulting rosette morphology, whereby the polymer is molecularly dispersed on the nanoscale throughout the ceramic.