Real-Time 1H and 31P NMR spectroscopy of the copolymerization of cyclic phosphoesters and trimethylene carbonate reveals transesterification from gradient to random copolymers

Copolymerization is the general approach to combine properties of different polymers in a single material. We prepared first trimethylene carbonate (TMC) phosphoester (PE) copolymers by statistical copolymerization using either stannous octanoate or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as respective catalyst. Variation comonomer feed, reaction temperature and solvent, resulted library with molar masses up 83,000 g/mol moderate mass dispersities (<1.8). The monomer consumptions during copolymerizations were followed real-time 1H 31P NMR spectroscopy solution bulk. As ring-opening cyclic esters often leads gradient copolymers, also TMC PE i.e. P(TMC-grad-PE)s, strength depending on conditions. If suitable transesterification catalyst like was used, randomization copolymer occurred. shift incorporated units used probe monitor spectroscopy. P-comonomer acts an ideal for situ monitoring changes copolymers’ microstructure following evolution diads triads. This paper focusses procedure gives detailed information about structure kinetics copolymerization. data give possibility understand processes molecular scale fine-tune polycarbonate-polyphosphoester future applications.