Controlled Polymerization of N-Substituted Glycine N-Thiocarboxyanhydrides Initiated by Rare Earth Borohydrides toward Hydrophilic and Hydrophobic Polypeptoids

• DOI: 10.1021/ma501131t
• Publication Date: 2014-09-23T04:12:22Z
• Authors: Xinfeng Tao; Yangwei Deng; Zhiquan Shen; Jun Ling
• Keywords: Sarcosine; Thermal Stability; Cloud point

N-substituted glycine N-thiocarboxyanhydrides (NTAs) are alternative monomers to prepare polypeptoids with large-scale producing potential compared the corresponding N-carboxyanhydrides (NCAs) due their easily synthetic approach and stability during purification storage. Novel monomer N-butylglycine NTA (NBG-NTA) has been synthesized well characterized for first time. Rare earth borohydrides [RE(BH4)3(THF)3, RE = Sc, Y, La, Nd, Dy, Lu] have applied in polymerization of sarcosine (Sar-NTA) NBG-NTA achieve high molecular weight (MW) hydrophilic hydrophobic polypeptoids. Polysarcosines (PSars), poly(N-butylglycine)s (PNBGs), copolymers yields, MWs, moderate MW distributions at 60 °C by using RE(BH4)3(THF)3 initiators. MWs controlled feed molar ratios. For instance, PSar an absolute Mn 27.7 kDa (DP 390) PDI 1.14 is produced successfully from Sar-NTA. Thermoresponsive random copolypeptoids poly(sarcosine-r-N-butylglycine)s [P(Sar-r-NBG)s] reversible phase transitions (cloud point temperature) aqueous solution minimal cytotoxicity comparable PEG PSar, which promising various biomedical biotechnological applications. Thermal properties homo- co-polypeptoids investigated TGA DSC measurements.