Solution Properties of Star and Linear Poly(<i>N</i>-isopropylacrylamide)

Plummer, Ronda; Hill, David J. T.; Whittaker, Andrew K.

doi:10.1021/ma0614545

Cited by 183 publications

(166 citation statements)

References 52 publications

Supporting

Mentioning

158

Contrasting

Unclassified

Order By: Relevance

“…All Tc values were within the same range and independent from molecular weight. This discovery agreed with the observations from Whittaker and coworkers [43]. They reported that the LCST transitions of a four arm star PNIPAAm based on a pentaerythritol moiety were depressed by the presence of the hydrophobic star core.…”

Section: Thermal Phase Transition Behavior Of Star-like Pnipaam Homo supporting

confidence: 91%

Synthesis of β-cyclodextrin-Based Star Block Copolymers with Thermo-Responsive Behavior

et al. 2015

View full text Add to dashboard Cite

Star polymers are one example of three-dimensional macromolecules containing several arms with similar molecular weight connected to a central core. Due to their compact structure and their enhanced segment density in comparison to linear polymers of the same molecular weight, they have attracted significant attention during recent years. The preparation of block-arm star copolymers with a permanently hydrophilic block and an "environmentally" sensitive block, which can change its nature from hydrophilic to hydrophobic, leads to nanometer-sized responsive materials with unique properties. These polymers are able to undergo a conformational change or phase transition as a reply to an external stimulus resulting in the formation of core-shell nanoparticles, which further tend to aggregate. Star-shaped copolymers with different cores were synthesized via atom transfer radical polymerization (ATRP). The core-first method chosen as synthetic strategy allows good control over the polymer architecture. First of all the multifunctional initiators were prepared by esterification reaction of the hydroxyl groups with 2-chloropropionyl chloride. Using β-cyclodextrin as core molecules, which possess a well-defined number of functional groups up to 21, allows defining the number of arms per star polymer. In order to prepare stimuli-responsive multi-arm copolymers, containing a stimuli-responsive (poly(N-isopropylacrylamide) (PNIPAAm)) and a non-responsive block (poly(N,N-dimethylacrylamide) (PDMAAm)), consecutive ATRP was carried out. The polymers were characterized intensively using NMR spectroscopy OPEN ACCESSPolymers 2015, 7 922 and size exclusion chromatography (SEC), whereas the temperature-depending aggregation behavior in aqueous solution was determined via turbidimetry and differential scanning calorimetry (DSC).

show abstract

Section: Thermal Phase Transition Behavior Of Star-like Pnipaam Homo supporting

confidence: 91%

Synthesis of β-cyclodextrin-Based Star Block Copolymers with Thermo-Responsive Behavior

et al. 2015

View full text Add to dashboard Cite

show abstract

“…For Type II polymers, the architecture has a negligible effect (e.g. the LCST of star PiPAAms is similar to that of linear polymer [109]), except for polymers with hydrophobic or hydrophilic end-groups [110][111][112] and polymers with a high number of arms [113] or spherical brushes [114,115]. Type III polymers [e.g.…”

Section: Phenomenological Classificationmentioning

confidence: 99%

Non-ionic Thermoresponsive Polymers in Water

Aseyev

Tenhu

Winnik

2010

Advances in Polymer Science

456

511

View full text Add to dashboard Cite

Numerous non-ionic thermally responsive homopolymers phase separate from their aqueous solutions upon heating. Far fewer neutral homopolymers are known to phase separate upon cooling. A systematic compilation of the polymers reported to exhibit thermoresponsive behaviour is presented in this review, including N-substituted poly[(meth)acrylamide]s, poly(N-vinylamide)s, poly(oxazoline)s, protein-related polymers, poly(ether)s, polymers based on amphiphilic balance, and elastin-like synthetic polymers. Basic properties of aqueous solutions of these polymers are briefly described.

show abstract

“…[118] Better results in terms of molecular weight distribution were often achieved with other monomers such as PNIPAAm [119,120] and acrylates. [121,122] Reason may be a better segmental diffusion of these polymers.…”

Section: Divergent Star Synthesismentioning

confidence: 99%

Hairy Core–Shell Nanoparticles via RAFT: Where are the Opportunities and Where are the Problems and Challenges?

Stenzel

2009

Macromol. Rapid Commun.

View full text Add to dashboard Cite

The preparation of hairy core-shell nanoparticles including (crosslinked) micelles, unimolecular micelles such as star polymers with block structures in each arm and surface grafted nanoparticles such as inorganic particles via the RAFT process are discussed. The RAFT process is certainly a highly versatile process. However, it should not be forgotten that RAFT polymerization is a process, i.e., superimposed on a conventional free radical process. Furthermore, the livingness of the process is dependent on the accessibility of the RAFT group, which can be hampered in certain approaches such as star synthesis and surface grafting from nanoparticles. Nevertheless, the RAFT process is a versatile toolbox that offers good solutions to a range of problems in the preparation of hairy nanoparticles.

show abstract

Solution Properties of Star and Linear Poly(N-isopropylacrylamide)

Cited by 183 publications

References 52 publications

Synthesis of β-cyclodextrin-Based Star Block Copolymers with Thermo-Responsive Behavior

Synthesis of β-cyclodextrin-Based Star Block Copolymers with Thermo-Responsive Behavior

Non-ionic Thermoresponsive Polymers in Water

Hairy Core–Shell Nanoparticles via RAFT: Where are the Opportunities and Where are the Problems and Challenges?

Contact Info

Product

Resources

About