Cyclic polymers synthesized by ring-closure method from linear precursors contain some of linear contaminates. In this work, the origin of linear contaminates in cyclic polystyrenes (c-PS) is demonstrated by the coupling of liquid chromatography at the critical condition (LCCC) with matrix-assisted laser desorption/ionization time-of-flight mass spectra. The linear contaminates are revealed to be the “dead” chains during ATRP by chain termination, the unreacted linear polystyrene (l-PS) precursors, and the dimers by the imperfect ring-closure reaction. The c-PS are purified by LCCC fractionation, and the results show the LCCC fractionation at the critical adsorption point (CAP) of c-PS is more efficient than that at the CAP of linears for low molecular weight (<10,000) PS. A two-step LCCC method is presented for the preparation of c-PS with high purity (>99.6%) via the tandem-coupled LCCC fractionation at the CAP of l-PS and at the CAP of c-PS.
Polymer – Elsevier
Published: Jan 17, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.
All for just $49/month
It’s easy to organize your research with our built-in tools.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud