Aqueous‐solution and solid‐film properties of poly(vinyl alcohol), poly(vinyl pyrrolidone), gelatin, starch, and carboxymethylcellulose polymers

Abstract

With the density and viscosity results for five polymers-poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), gelatin (Ge), starch (St), and carboxymethylcellulose (CMC)-measured in aqueous solutions at different temperatures, we have computed the excess molar volumes and activities. Smaller excess molar volumes for PVA solutions are attributed to specific types of interactions, whereas for other polymers, these data are quite large, indicating dispersiontype interactions. The activity data of the polymer solutions vary widely, depending on the nature of the polymers and their intermolecular interactions. The freestanding film properties of the polymers indicate that Ge and PVA produce stable films, whereas brittle films can be obtained for PVP and St. The mechanical strength properties of PVA and CMC have been found to be suitable for membrane fabrication.

CNF-reinforced polymer aerogels: Influence of the synthesis variables and economic evaluation

“…Atomic mass units (a.m.u) of 15,18,43,44,60,78 and 91 -corresponding to fragment ions CH 4 , H 2 O, CH 3 CO, CO 2 , C 2 H 4 O 2 , C 6 H 6 , and C 7 H 8 , respectively, according to the database of National Institute of Standards and Technology (NIST) -were obtained in the MS spectra. The third degradation step (400-500°C), corresponding to a total weight loss of 27 wt.%, was dominated by chain-scission reactions, cyclization and continual degradation of residual acetate groups [67,69,70]. Finally, the maximum release of aromatic compounds took place between 180 and 410°C.…”

Emission Analysis Of Pr[sup 3+]: PVP And Nd[sup 3+]: PVP Films

“…Correspondingly the weight loss in TG line is 18% at temperature range from 470 to 605°C. 12 The absorption spectrum of Pr 3+ : PVP shows three bands as shown in Fig. 5.…”

Tailor-Made Aerogels Based on Carbon Nanofibers by Freeze-Drying

“…However, PVA, PVP, gelatin and arabic gum, which are soluble in water and in a wide range of organic solvents, produced CNF aerogels with a dense 2D sheet-like structure. [41][42][43][44] This fact suggests that the hydrophilic character of the polymer can affect the final structure. In a freeze drying process, the rapid sublimation of ice particles in the polymer structure could generate a very high porosity.…”