Swelling characteristics

Crystallization and Melting Point. The abihty of PVA to crystallize is the single most important physical property of PVA as it controls water solubiUty, water sensitivity, tensile strength, oxygen barrier properties, and thermoplastic properties. Thus, this feature has been and continues to be a focal point of academic and industrial research (9—50). The degree of crystallinity as measured by x-ray diffraction can be directly correlated to the density of the material or the swelling characteristic of the insoluble part (Fig. 2). 

TABLE 2.6 Swelling Characteristics of Sephacryl HR in Various Solvents"... 

A tetrahydrofuran cross-linked PS-based insoluble support (/anda/el) has also been developed and shown to tolerate microwave heating by Janda and coworkers [75]. /anda/el is commercially available and reported to offer better swelling characteristics, increased homogeneity and site-accessibiUty, as well as a more organic solvent-like environment compared to divinylbenzene cross-hnked polymers. 

The networks swelled isotropically indicating the co-continuous nature of the materials. The range of swelling for the PHEMA-1-PIB networks is significantly less than that of PDMAAm-i-PIB demonstrating that amphiphilic networks exhibiting various desired swelling characteristics can be obtained by the selection of network components. 

DC Harsh, SH Gehrke. Controlling the swelling characteristics of temperature-sensitive cellulose ether hydrogels. J Controlled Release 17 175-186, 1991. 

The similarity of results for peptide resins in both solvents fits nicely with the estimate that this resin sample with about 50 weight % peptide should have similar swelling characteristics in the two solvents (3). In these samples we have measured the integrals of the aromatic region relative to an unenriched peptide peak, and the results are consistent with the observation of all the carbon nuclei, and hence the results are typical of all portions of the cross-linked matrix. 

In consideration of the clinical importance of being able to visualize any implant material within the body, radio-opaque hydrogels for NPR have been formulated [69]. Copolymers of iodobenzoyl-oxo-ethyl methacrylate (4IEMA) and hydrophilic PVP or hydroxylethyl methacrylate (HEMA) exhibit appropriate swelling characteristics, viscoelastic mechanical properties, and excellent cytocompatibility [69]. Moreover, inclusion of the covalently attached iodine molecules allowed for hydrogel visualization via X-ray in a porcine cadaveric spine model [69],... 

Poly(methyl methacrylate) [PMMA] is an excellent polymer for studying photoresist dissolution because of its minimal swelling characteristic. For this work, PMMA molecules were labelled with phenanthrene (Phe) dye since its fluorescence is quenched by MEK. In addition, this dye has the advantage of forming few excimers (23-241 which results in self-quenching. Thus, the reduction in fluorescence intensity of PMMA-Phe is virtually solely due to MEK quenching. Consequently, the permeation of MEK into a PMMA film can be monitored from fluorescence intensity decay. 

Qi, X., Tester, R. F., Snape, C. E., Yuryev, V., Wasserman, L. A., and Ansell, R. (2004). Molecular basis for the gelatinisation and swelling characteristics of waxy barley starches grown at the same location during the same season. Part 11. Crystallinity and gelatinisation characteristics. J. Cereal Sci. 39, 57-66. 

The pH responsiveness of a 3-PAA/Au graft that was amidated with N,N-dimethylaminoethylenediamine was also studied by in situ ellipsometry [32]. This amine-containing graft had pH dependent swelling characteristics that were opposite to those of the - C02H-rich graft because the amine-rich film... 

Swelling Characteristics and Activities of CopoIy(A -isopropylacrylaniide-acrylaniide) Gels Containing Immobilized Asparaginase... 

General stmcture (fibrous or beaded form), particle size and variation, pore structures and dimensions, surface chemistry (hydrophilic or hydrophobic), swelling characteristics of matrix are important factors which effect chromatographic resolution [11,18]. Porosity of ion exchange... 

Choi, S. -G., Kerr, W. L. (2004). Swelling characteristics of native and chemically modified wheat starehes as a function of heating temperature and time. Starch, 56,181-189. 

Swelling Characteristics. The rate and uniformity with which casting powder granules are plasticized by casting solvent are critical in determining the proper cure conditions and the properties of the final propellant. Swelling characteristics are measured by dilatometric and microscopic techniques described in detail later. 

Acrylic acid can be used simultaneously as a monomer and as the solvent, the polyamide solution being frozen at dry ice temperature and ground in a vibration mill. The graft copolymer is said to be formed by mechanosynthesis and was confirmed by nitrogen analysis and solubility as well as swelling characteristics (5). 

While considering swelling characteristics of ebonite two facts are noteworthy 1) high sulphur and adequate cure reduce both the... 

Harsh DC (1992) Controlling swelling characteristics of novel cellulose ether gels. Thesis, University of Cincinnati, Cincinnati OH... 

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