摘要
It remains a challenging task to achieve ring-opening(co)polymerization(ROP)of macrolactones.Hence,we synthesized a series of Al-based catalysts and systemically investigated the effect of N-containing substituent on the sidearms on ROP of macrolactones.Al3 possessing Nmethyl group could effectively achieve controlled ROP of pentadecalactone(PDL)and macro(di)lactone ethylene brassylate(EB)in combination with BnOH,furnishing polyethylene-like PPDL and PEB with M_(W)up to 90.3 and 321 kg/mol,respectively.Random copolymerization of PDL and small-ring lactonesε-caprolactone(e-CL)andδ-valerolactone(δ-VL)could prepare random copolyesters with tailored T_(m)in the range of 57-94℃by controlling the ratios of PDL and e-CL,6-VL.More importantly,well-defined block copolyesters could be obtained by sequential adding PDL andε-CL,δ-VL,which have been proved by GPC-MALLS,DSC and^(13)C-NMR.
基金
the National Natural Science Foundation of China(Nos.22225104,22071077,21871107 and 21975102)
China Postdoctoral Science Foundation(Nos.2022TQ0115 and 2022M711297)。