To address a need for highly X-ray opaque biodegradable materials, a series of poly(epsilon-caprolactone) derivatives were prepared using oxime post-polymerization modification to conjugate two different iodinated hydroxylamines. These materials were synthesized with up to 3 wt. % iodine content and demonstrated improved X-ray contrast relative to both the ketone precursors and previously reported monoiodinated materials. (C) 2016 Wiley Periodicals, Inc.