Kentucky Junior Academy of Science 2000 Symposium Abstracts

 

Determination of Reactivity Ratios for Polyacrylate Elastomers. WEI DENG, CLAYTON SMITH, duPont Manual High School, Louisville, KY, 40208.
     The automobile industry has recently shown an extreme favoritism towards the acrylate elastomers, namely, ethyl acrylate (EA), methoxyethyl acrylate (MEA), and n-butyl acrylate (BA).  Because EA has a high transition state, and because BA has poor oil resistance, the most auspicious combination of acrylates is that of EA and MEA.  However, even with the advances in production, there has not been a record of their reactivity ratios, an essential tool used in tailor-making copolymers.  Hydrogen nuclear magnetic resonance spectroscopy (¹H NMR) was used to analyze polymers synthesized in a temperature-controlled environment with bubbling argon gas.  The data from 1H NMR were substituted into equations to find the reactivity ratios.  The calculated reactivity ratios of EA and MEA in poly(EA co-MEA) were 0.6580 and 2.0074 respectively.  In poly(EA co-VBC), the ratios were 0.0080 (EA) and 6.7180 (VBC).  These numbers indicate that EA polymerizes three times as fast as MEA, and VBC 840 times as fast as EA. An extension of the concept applied in this project would be to investigate other reactivity ratios and develop polymerization models to aid chemical companies in creating efficient production algorithms.

[Abstract Index]