Quantitative Analysis of Polyacrylamide Grafted on Polylactide Film Surfaces Employing Spectroscopic Techniques

Standard techniques for quantitative measurement of polyacrylamide (PAm) contents grafted on polylactide (PLA) film substrates, P(LA- g-Am- co-MBAm), which are commonly used as cell culture substrates or scaffolds, and pH-sensitive absorbents have been developed with X-ray photoelectron (XPS), proton-nuclear magnetic resonance (¹H-NMR), and Fourier transform infrared (FT-IR) spectroscopy. The techniques are then applied to examine P(LA- g-Am- co-MBAm) samples prepared from two separate photo-initiator/co-initiator systems. Efficiency and accuracy of the techniques are compared. The results from all techniques are in good agreement, indicating high analysis precisions, although FT-IR technique provides additional advantages, in terms of short analysis time, ease of sample preparation, and accessibility of a machine. The results indicate that the riboflavin (RF) initiator system has higher grafting efficiency than its camphorquinone (CQ) counterpart. These standard techniques can be applied in the analysis of these materials and further modified for quantitative analysis of other grafting systems.