Determination of the polymerisation rate of a low-toxicity diacetone acrylamide-based holographic photopolymer using Raman spectroscopy

• We use Raman spectroscopy to determine the polymerisation rate in a low-toxicity Diacetone Acrylamide (DA)-based photopolymer.
• We examine the influence of the addition of glycerol to the photopolymer on the polymerisation rate.
• The results are discussed in the context of resulting chain length distribution and disorder in the polymer system.

The polymerisation rate of a low-toxicity Diacetone Acrylamide (DA)-based photopolymer has been measured for the first time using Raman spectroscopy. A value for the polymerisation rate of 0.020 s−1 has been obtained for the DA photopolymer by modelling the polymerisation reaction dynamics as a stretched exponential or Kohlrausch decay function. This is significantly lower than the polymerisation rate of 0.100 s−1 measured for the well known Acrylamide (AA)-based photopolymer composition. The effect of the additive glycerol on the polymerisation rate of the DA-based photopolymer has also been investigated. The inclusion of glycerol is observed to increase the rate of polymerisation of the DA photopolymer by up to 60%. It is also observed that the polymerisation rate of the DA photopolymer is less dependent on the recording intensity when glycerol is present.