Instrument for measuring torsional creep and recovery Patent

Measuring shear-creep compliance of solid and liquid materials used in spacecraft component

Viscoelastic behavior of polymers at long times seventh semiannual report, period ending 31 oct. 1964

Polymer behavior in cross linked systems in rubbery region, response of linear amorphous polymers, and viscoelasticity of nonpolar small molecule compound at glass temperatur

Viscoelastic Behavior of Polymers at Long Times Final Report

Viscoelastic behavior of polymers at long time, and torsional creep apparatus developmen

Viscoelastic behavior of polymers at long times Ninth semiannual report, period ending 31 Oct. 1965

Viscoelastic behavior of cross linked polymers as related to molecular structure - material testin

Effect of crosslink density on the creep behavior of natural rubber vulcanizates

Torsional creep measurements on cross-linked natural rubber vulcanizate

Viscous and Viscoelastic Behavior of 1,3,5-tri-alpha-naphthyl Benzene

Torsional creep and creep recovery behavior of organic liquid

Plasticization and antiplasticization of polymer melts diluted by low molar mass species

An analysis of glass formation for polymer melts that are diluted by structured molecular additives is derived by using the generalized entropy theory, which involves a combination of the Adam-Gibbs model and the direct computation of the configurational entropy based on a lattice model of polymer melts that includes monomer structural effects. Antiplasticization is accompanied by a "toughening" of the glass mixture relative to the pure polymer, and this effect is found to occur when the diluents are small species with strongly attractive interactions with the polymer matrix. Plasticization leads to a decreased glass transition temperature T_g and a "softening" of the fragile host polymer in the glass state. Plasticization is prompted by small additives with weakly attractive interactions with the polymer matrix. The shifts in T_g of polystyrene diluted by fully flexible short oligomers are evaluated from the computations, along with the relative changes in the isothermal compressibility at T_g to characterize the extent to which the additives act as antiplasticizers or plasticizers. The theory predicts that a decreased fragility can accompany both antiplasticization and plasticization of the glass by molecular additives. The general reduction in the T_g and fragility of polymers by these molecular additives is rationalized by analyzing the influence of the diluent's properties (cohesive energy, chain length, and stiffness) on glass formation in diluted polymer melts. The description of glass formation at fixed temperature that is induced upon change the fluid composition directly implies the Angell equation for the structural relaxation time as function of the polymer concentration, and the computed "zero mobility concentration" scales linearly with the inverse polymerization index N.Comment: 12 pages, 15 figure