Viscoelastic relaxation processes factor into polymer performance and stability throughout an application lifetime. These relaxations are controlled by the polymer network structure and dynamics which occur at different orders of magnitude in time. In most cases, simultaneous sampling techniques for viscoelastic processes are limited by high cost and complicated design. In this work, we detail the design and operation of an independent array of surface indentations which can measure the response of multiple points on a polymer substrate. Demonstrations of the range and capabilities of this technique are combined with composition or temperature gradients, which exhibit the ability to generate viscoelastic results under unique conditions for each indentation. Methacrylate photopolymer systems are measured at different compositions simultaneously within an indenter array to increase the measurement throughput, with a measured creep compliance range from 10-9 Pa-1 to 10-5 Pa-1. The application of temperature gradients allows for the viscoelastic measurements to be assembled into a master curve using time-temperature superposition.
Citation: Review of Scientific Instruments
Pub Type: Journals
creep, compliance, high-throughput, viscoelastic, polymers, gradient