One-Pot Double Modification of p(NIPAAm): A Tool for Designing Tailor-Made Multiresponsive Polymers.

A quantitative, additive-free, and one-pot reaction cascade involving the ring-opening of a thiolactone by primary amine treatment and subsequent conversion of the released thiol groups via Michael addition to an acrylate has been utilized for the double modification/functionalization of poly(N-isopropyl acrylamide), yielding tailor-made thermoresponsive polymers. After proving a quantitative double functionalization, different amine/acrylate combinations were employed in order to demonstrate the general applicability of the concept. Cloud points can be tuned by adjusting the amount of ring-opening amine in the reaction mixture, which enables to control the degree of modification.

From NMP to RAFT and thiol-ene chemistry by in situ functionalization of nitroxide chain ends.

A straightforward, novel strategy based on the in situ functionalization of polymers prepared by nitroxide-mediated polymerization (NMP), for the use as an extension toward block copolymers and post-polymerization modifications, has been investigated. The nitroxide end group is exchanged for a thiocarbonylthio end group by a rapid transfer reaction with bis(thiobenzoyl) disulfide to generate in situ reversible addition-fragmentation chain transfer (RAFT) macroinitiators. Moreover, not only have these macroinitiators been used in chain extension and block copolymerization experiments by the RAFT process but also a thiol-terminated polymer is synthesized by aminolysis of the RAFT end group and subsequently reacted with dodecyl vinyl ether by thiol-ene chemistry.

Additive-free clicking for polymer functionalization and coupling by tetrazine-norbornene chemistry.

Herein we report the use of a tetrazine-norbornene inverse electron demand Diels-Alder conjugation applied to polymer end-functionalization and polymer-polymer coupling. The reaction was found to be applicable to polymer-polymer coupling, as judged by SEC, DOSY NMR, and LCxSEC analyses, giving diblock copolymers by merely mixing the constituent homopolymers together under ambient conditions, using no catalyst, additive, or external stimulus.