Reactive Secondary Sequence Oxidative Pathology Polymer Model and Antioxidant Tests
Richard C. Petersen *
University of Alabama at Birmingham, SDB 539, 1919 7th Avenue South, Biomaterials and Biomedical Engineering, Birmingham AL 35294, USA
*Author to whom correspondence should be addressed.
Abstract
Aims: To provide common Organic Chemistry/Polymer Science thermoset free-radical crosslinking Sciences for Medical understanding and also present research findings for several common vitamins/antioxidants with a new class of drugs known as free-radical inhibitors.
Study Design: Peroxide/Fenton transition-metal redox couples that generate free radicals were combined with unsaturated lipid oils to demonstrate thermoset-polymer chain growth by crosslinking with the α-β-unsaturated aldehyde acrolein into rubbery/adhesive solids. Further, Vitamin A and beta carotene were similarly studied for crosslink pathological potential. Also, free-radical inhibitor hydroquinone was compared for antioxidant capability with Vitamin E.
Place and Duration of Study: Department of Materials Science and Engineering and Department of Biomaterials, University of Alabama at Birmingham, between June 2005 and August 2012.
Methodology: Observations were recorded for Fenton free-radical crosslinking of unsaturated lipids and vitamin A/beta carotene by photography further with weight measurements and percent-shrinkage testing directly related to covalent crosslinking of unsaturated lipids recorded over time with different concentrations of acrolein. Also, hydroquinone and vitamin E were compared at concentrations from 0.0-7.3wt% as antioxidants for reductions in percent-shrinkage measurements, n = 5.
Results: Unsaturated lipid oils responded to Fenton thermoset-polymer reactive secondary sequence reactions only by acrolein with crosslinking into rubbery-type solids and different non-solid gluey products. Further, molecular oxygen crosslinking was demonstrated with lipid peroxidation and acrolein at specially identified margins. By peroxide/Fenton free-radical testing, both vitamin A and beta-carotene demonstrated possible pathology chemistry for chain-growth crosslinking. During lipid/acrolein testing over a 50 hour time period at 7.3wt% antioxidants, hydroquinone significantly reduced percent shrinkage greatly compared to the standard antioxidant vitamin E, %shrinkage at 11.6 ±1.3 for hydroquinone and 27.8 ±2.2, for and vitamin E, P = .001.
Conclusion: Free radicals crosslinked unsaturated lipid fatty acids into thermoset polymers through Fenton reactions when combined with acrolein. Further, hydroquinone was a superior antioxidant to vitamin E.
Keywords: Thermoset polymer, unsaturated lipid, hydroquinone, vitamin A, vitamin E