Free‐radical homo‐ and copolymerization of vinyl acetate and n‐butyl acrylate: Kinetic studies by online ¹H NMR kinetic experiments

Abstract

A percutaneous, osseointegrated (OI) prosthetics are alternative docking systems for upper‐ and lower‐extremity prostheses. Persistent inflammation and micro‐motion are known to cause negative soft‐tissue adaptation in wound healing and may also be detrimental to implant longevity. In this study, a unique single‐stage sheep amputation and implantation model was developed to assess the efficacy of a porous coated sub‐dermal fixation surface in the prevention of skin regression around a percutaneous osseointegrated prosthetic implant. Porous coated and smooth sub‐dermal fixation surface prosthetics were implanted in the right forelimb of skeletally mature sheep for up to 12 months. Skin regression kinetics and sub‐dermal fixation surface coverage were measured from histological samples. Quantitative measurements of porous coated surfaces yielded skin migration rates of 0.90 ± 0.23, 0.56 ± 0.15, 0.44 ± 0.22 mm/month for the 6, 9, and 12 month animals, respectively. In addition, three load dependent regions of skin adaptation were identified; an interface, a transition, and a stress absorbance region. Immediate post‐implantation immobilization of the skin may foster improved load‐bearing percutaneous device outcomes. The skin adaptations reported here will aid in informing the design and optimization of future percutaneous, OI devices intended for the treatment of upper‐ and lower‐extremity amputees. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.

An In‐Situ NMR Study of Radical Copolymerization Kinetics of Acrylamide and Non‐Ionized Acrylic Acid in Aqueous Solution

“…Overall Monomer Conversion Experiments were conducted with nonionized monomer and initial compositions of f AA0 ¼ 0.0, 0.2, 0.5, 0.7, and 1.0 at initial 40 Figure 9 demonstrates the influence of the initial monomer concentration on the measured monomer conversion profiles, while Figure 10 shows the effect of monomer composition. Figure 11 plots the initial rate of monomer conversion for all experiments, dx/dt, as estimated from the linear portion of the profiles between 0 and 40% conversion.…”

“…The group of Mahdavian has studied AM homopolymerization in aqueous solution [28] as well as various copolymerization in organic solution. [37][38][39][40] Three criteria for running in-situ NMR experiments were reported: [28] 1) a reaction rate that is less than the scanning rate, 2) solubility of the polymer in the solvent, and 3) distinguishable monomer/ polymer peaks so that monomer composition and conversion can be determined. A fourth criterion, namely that isothermal conditions are maintained, should be added.…”

Preparation and Characterization of Soap-Free Vinyl Acetate/Butyl Acrylate Copolymer Latex

“…When BA copolymerizes with the VAc monomer, it can protect the ester group of the VAc chain and reduce the hydrolysis rate of the ester group. Thereby, the shortcomings such as water resistance and stability of the polyvinyl acetate emulsion are improved [7][8][9].…”

Improvement in Wood Bonding Strength of Poly (Vinyl Acetate-Butyl Acrylate) Emulsion by Controlling the Amount of Redox Initiator

“…Owing to the fascinating properties of polyvinyl alcohol (PVA), it was used as a protective colloid to provide the initial stage of the emulsion polymerization and could be grafted by other monomers [ 5 ]. In addition, due to the milky white color of the liquid, it is also called white latex and it is currently widely used in coatings, fireproof coatings, adhesives, and other industries [ 6 , 7 , 8 ].…”