Viscometric study of gelatin in dilute aqueous solutions

Abstract

The viscosities of aqueous solutions of gelatin at different temperatures were carefully measured in a common glass‐capillary Ubbelohde viscometer at dilute to extremely dilute concentrations. The adsorption effect that occurred in the viscosity measurements was theoretically analyzed and discussed. A theory based on Langmuir isotherms could adequately describe the existing data. Some structural information was obtained by the use of an iterative fitting procedure to treat the reduced viscosity data, which disclosed that individual gelatin chains underwent a coil‐to‐helix transition as the solution cooled from 40 to 15 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1804–1812, 2006

Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR

“…[234][235][236][237][238][239][240][241][242][243] On the other hand, PBT is quite resistant to hydrolysis and the replacement of terephthalic units by aliphatic ones by copolymerization has been reported as an alternative to enhance its hydrolytic degradation or even its biodegradation. [ 93,229,[244][245][246][247][248][249][250][251][252][253][254][255][256][257][258][259][260][261][262] NMR has been again the technique of choice in all the above referenced works to characterize the PBT copolyesters including the precise determination of their compositions and microstructures. [ 87,88,116, One of these examples are the random copolyesters composed of 1,4-butanediol, adipic acid, and terephthalic acid, poly(butylene terephthalate-co -adipate)s (PBA x T y ).…”

Interactions of Sodium Dodecyl Benzene Sulfonate and Sodium Dodecyl Sulfate with Gelatin: A Comparison

“…The solutions were kept at this temperature for at least 30 min to attain thermal equilibrium. At this temperature, gelatin is characterized macroscopically as a random coil in dilute solutions with a length of *20 Å [13][14][15].…”

Modeling of Coesterification Process for Biodegradable Poly(Butylene Succinate‐co‐Butylene Terephthalate) Copolyesters

“…Moreover, bio-based raw materials, succinic acid (SA), and 1,4-butanediol (BDO) can be used in its synthesis. Therefore, PBST has been intensively studied in the synthesis, [2] catalyst, [3] properties, [4][5][6][7][8][9][10][11] biodegradations, [12][13][14] and processability. [15,16] However, most efforts are limited at of TPA.…”

“…Due to the differences in the esterification activity between aliphatic diacid and aromatic diacid, their appropriate esterification temperatures are different. [2,6,12] The lower rate constants and heterogeneity make TPA/BDO esterification slower than SA/BDO, so higher temperature (above 200 °C) is needed to reach satisfactory esterification rate. [17] The traditional esterification process in two reactors in series or parallel is suitable for the esterification of aliphatic/aromatic copolyesters due to its stability and flexibility as the reaction temperatures can be easily controlled in two independent reactors.…”