Reference

Optically sensitive materials of different moduli for modeling laminated media by the freezing photoelastic measuring method

Optically sensitive materials of different moduli for modeling laminated media by the freezing photoelastic measuring method. Kolar, Frantisek (Ustav Geol. Geotech., CSAV, Prague, Czech.). Plasty Kauc., 21(9), 262-5 (Czech) 1984. CODEN: PLKCAS. ISSN: 0322-7340. DOCUMENT TYPE: Journal CA Section: 38 (Plastics Fabrication and Uses) Optically sensitive materials for modeling of laminated media (e.g., slopes of open pit mines), which can be studied by the freezing plastoelastic method, were prepd. by curing CHS 15 [25068-38-6] epoxy resin with maleic anhydride [108-31-6] and phthalic anhydride [85-44-9] using N,N-dimethylaniline [121-69-7] as catalyst. The elasticity modulus (Ee) of the cured products in rubbery state can be controlled by adjusting the anhydride concn. The existence of a nonzero residual stress was obsd. after freezing of multilayer models built by bonding layers with different Ee values which were not preliminarily exposed to stress. This effect (explained by different thermal expansions of the individual layers) can be eliminated by using materials with equal glass transition temps. (Tg) and approx. equal ag consts. (ag = tangent of the temp. dependence of the elongation of the cured polymer in the glassy region). The Tg value of the cured resin can be affected not only by the type and amt. of curing agent but also by introducing various side chains to the polymer network. The effect of addn. of dibenzyl phthalate [523-31-9] to the reaction mixt. on Tg, Ee, and optical sensitivity of the cured product was studied.