Topological defects in polymer networks profoundly affect the mechanical properties of the materials, and it is therefore pivotal to quantify the amount of defects in the network. While recent work from our group has successfully quantified the primary loops, it has been challenging to measure the fraction of high-order loops, which also significantly affect the mechanical properties of materials. In this work, we demonstrate a method in which a non-degradable tracer is introduced, enabling the direct experimental measurement of both primary and secondary loops. The concentration dependence of the primary and secondary loop fractions matches excellently with that obtained from theories. Semi-batch slow addition technique is applied to the synthesis of the polymer networks and it is found to decrease both primary and secondary loops, compared to the batch mixing method. In addition, with the measured primary and secondary loop fractions, we are able to obtain a close estimation of the elastic shear modulus by conducting the first two order real elastic network theory calculation.

Network disassembly spectrometry with a non-degradable tracer: counting primary and secondary loops in polymer networks

255th National Meeting (2018)

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