Title

Liquid Crystallinity: Medium Effects on Photopolymerization Rates

Document Type

Article

Publication Date

10-1-1992

Department

Polymers and High Performance Materials

Abstract

Ordering of the medium in which free radical polymerization is conducted can, under appropriate circumstances, alter the kinetics of the chain-growth process, resulting in enhanced rates. Since in many systems medium changes occur at higher conversion, it is important to take into account any alterations in the polymerization rate induced by such phenomena. We have found that exotherms initiated by individual laser pulses can be useful in identifying and providing detailed information concerning rate acceleration in liquid crystalline systems. From measurements of the pulse intensities in the sample cell, estimates of the quantum efficiency and kinetic chain length have been made directly from the integrated areas of the exotherm curves. Recent refinements in our sample geometry have allowed us to generate reproducible efficient data as a function of the degree of conversion and order in the polymerization medium.

Publication Title

Polymer Engineering and Science

Volume

32

Issue

20

First Page

1490

Last Page

1493