PHOTOINITIATED POLYMERIZATION OF 2-HYDROXYETHYL METHACRYLATE BY SAFRANIN T / TRIETHANOLAMINE IN AQUEOUS SOLUTION: A KINETIC STUDY
Journal Title: Baqai Journal of Health Sciences - Year 2016, Vol 19, Issue 2
Abstract
This study involves the polymerization of 2-hydroxyethyl metharylate (HEMA) (1–3 M), photoinitiated by safranin T (ST) / triethanolamine (TEOHA) system in the pH range 6.0–9.0. The kinetics of the reactions during the initial stages of polymerization (~5% HEMA conversion, within 150 s) has been evaluated to avoid the effects of any volume changes in the solution. The concentration of HEMA in polymerized solutions has been determined spectrometrically at 208 nm with a precision of ±3%. The apparent first-order rate constants (kobs) for the polymerization of HEMA by ST in the presence of 0.010 M TEOHA range from 2.57–6.08 (1 M), 2.14–5.44 (2 M) and 1.79–4.81×10–4 s–1 (3 M) at pH 6.0–9.0. The second-order rate constants for the interaction of TEOHA with HEMA (1–3 M) range from 1.79–6.08×10–2 M–1 s–1 at pH 6.0–9.0. This indicates that the reactivity of TEOHA radicals increases with an increase in pH of the solution. The viscosity of HEMA solutions exerts an influence on the rates of polymerization and the values of kobs show a linear relation with inverse of solution viscosity. This could be due to the quenching of the ST excited triplet state with an increase in the viscosity of the solution.
Authors and Affiliations
Iqbal Ahmad, Kefi Iqbal, Syed Abid Ali
Keywords
Related Articles
- EP ID EP200006
- DOI -
- Views 90
- Downloads 0
EFFECT OF STABILIZERS ON THE CHEMICAL AND PHOTODEGRADATION OF ASCORBIC ACID IN AQUEOUS SOLUTION
Ascorbic acid (vitamin C) is susceptible to light and air and forms various degradation products. A number of stabilizers have been used to study their effect on the degradation of ascorbic acid (AH2) in dark and light a...
TOTAL PARENTERAL NUTRITION (TPN): ROLE OF RIBOFLAVIN (VITAMIN B2) AND CYANOCOBALAMIN (VITAMIN B12)
Total parenteral nutrition (TPN) replaces and maintains essential nutrients in patients in whom oral or tube feedings are contraindicated or inadequate. A nutritional assessment must be carried out before initiating TPN...
DEVELOPMENT, VALIDATION AND KINETIC APPLICATION OF SPECTROMETRIC METHODS FOR THE ANALYSIS OF ASPIRIN, SALICYLIC ACID, AND CAFFEINE AS SINGLE-COMPONENT AND IN MIXTURES
Aspirin (ASA) and aspirin-caffeine dosage forms are widely used as analgesic drugs. In the present study specific stability-indicating two- and three-component spectrometric methods have been developed for the assay of A...
PHARMACEUTICAL GELS
Gels are three-dimensional semisolid systems formed by the interlinking of gelling agent and dispersion medium. They are non-invasive, less greasy, non-toxic, and inert to food and drugs. They have minimum side effects,...
ONGOING AUDIT OF ASSISTED REPRODUCTIVE TECHNIQUES (ART) AT BIRDS
Abstract is not available