25999-13-7Relevant articles and documents
Preparation of ABC triblock copolymers of N-alkyl substituted acrylamides by RAFT polymerization
Cao, Ya,Zhu
, p. 407 - 411 (2007)
Reversible addition-fragmentation chain transfer (RAFT) polymerization of N-alkyl substituted acrylamides has been carried out by the use of a trithiocarbonate (2-dodecylsulfanylthiocarbonyl-sulfanyl-2-methyl propionic acid) as the RAFT reagent. The N-alkyl groups of the acrylamide monomers are important in the RAFT process. N-alkyl monosubstituted Polyacrylamides are found to be active macro-chain transfer agents, while N,N-disubstituted monomers can react easily with them to form a sequent block. We have designed a synthetic pathway to successfully prepare ABC triblock copolymers of N-alkyl substituted acrylamides with low polydispersities (PDI 1.20) by a three-step RAFT polymerization process.
Linearly thermoresponsive core-shell microgels: Towards a new class of nanoactuators
Zeiser, Michael,Freudensprung, Ines,Hellweg, Thomas
, p. 6096 - 6101 (2012)
In this study we present novel core-shell microgels, with a shell made of poly(N-n-propylacrylamide) (pNNPAM) and a core consisting of poly(N-iso-propylmethacrylamide) (pNIPMAM), exhibiting a unique linear temperature response. The effect is produced by the large LCST gap of 23°C between the shell- and the core-forming polymer. We demonstrate that the shell exhibits a temperature induced de-swelling process that is almost independent of the swelling properties of the core. Furthermore the active collapse of the shell forces a collapse of the core (which is known as the so-called "corset-effect"). In a region between 25°C and 41°C the response of the particles is directly proportional to the temperature. Moreover, the core properties were systematically varied, revealing the possibility to linearly change the magnitude of the linear swelling. Hence, these particles are very promising as piezo-like linear nano-actuators.
STABLE MICELLES FORMED WITH DIBLOCK COPOLYMERS OF CRITICAL MICELLE CONCENTRATION COPOLYMER AND TEMPERATURE-SENSITIVE COPOLYMER
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, (2010/10/19)
A novel class of mixed micelles formed with critical micelle concentration (Cmc) character's diblock copolymer, and temperature-sensitive character's diblock copolymer were disclosed. The mixed micelles possess complementary effects in adjusting external temperature shift (storage vs. body temperature) and concentration change (dilution after intravenous injection). The mixed micelles of the present invention can serve as a potential injectable drug delivery system for anticancer drugs, such as doxorubicin and many others.