VI-244 4.6. Poly(benzimidazoles) VI-245 4.7. Poly(benzothiazinophenothiazines) VI-245 4.8. Poly(benzothiazoles) VI-245 4.9. Poly(benzoxazlnes) VI-245 4.10. Poly(benzoxazoles) VI-245 4.11. Poly(carboranes) VI-245 4.12. Poly(dibenzofurans) VI-246 4.13. Poly(dioxoisoindolines) VI-246 4.14. Poly(fluoresceins) VI-247 4.15. Poly(furan tetracarboxylic acid diimides) VI-247 4.16. Poly(oxabicyclononanes) VI-247 4.17. Poly(oxadiazoles) VI-248 4.18. Poly(oxindoles) VI-248 4.19. Poly(oxoisoindolines) VI-248 4.20. Poly(phthalazines) VI-248 4.21. Poly(phthalides) VI-248 4.22. Poly(piperazines) VI-248 4.23. Poly(piperidines) VI-249 4.24. Poly(pyrazinoquinoxalines) VI-249 4.25. Poly(pyrazoles) VI-249 4.26. Poly(pyridazines) VI-249 4.27. Poly(pyridines) VI-249 4.28. Poly(pyromellitimides) VI-249 4.29. Poly(pyrrolidines) VI-250 4.30. Poly(quinones) VI-250 4.31. Poly(quinoxalines) VI-250 4.32. Poly(triazines) VI-252 4.33. Poly(triazoles) VI-252 Table 5. Copolymers VI-252 G. References VI-253 A. INTRODUCTIONAmorphous (noncrystalline) polymeric solids are either glasses or rubbers. A glassy polymer lacks long range order, and is below the temperature at which molecular motions take place on the time scale of the experiment. A rubbery polymer is above the temperature at which molecular motions take place on the time scale of the experiment. The glass transition temperature, T g , is the critical temperature that separates glassy behavior from rubbery behavior. Many amorphous solids, including polymers, organic liquids, biomaterials, some metals and alloys, and inorganic oxide glasses, exhibit glass transition temperatures. The dramatic change in the local movement of polymer chains at T g leads to large changes in a host of physical properties. These properties include density, specific heat, mechanical modulus, mechanical energy absorption, dielectric coefficients, acoustical properties, viscosity, and the rate of gas or liquid diffusion through the polymer, to name a few. Any of these properties can be used, at least in a crude manner, to determine T g .
References page VI -253
Specific volume
Gl assCrystal l i zati on vol ume change Li qui d
