Preparation of poly(N‐isopropylmethacrylamide) latexes kinetic studies and characterization

Duracher, David; Elaı̈ssari, Abdelhamid; Pichot, Christian

doi:10.1002/(sici)1099-0518(19990615)37:12<1823::aid-pola12>3.3.co;2-r

Cited by 59 publications

(89 citation statements)

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“…Due to the huge number of polymers of this type, some biopolymers such as polysaccharides will not be described here. hysteresis is more pronounced than in the case of PiPAAm [86,284] Copolymers, effect of NaCl and other cosolutes [103] Thermoresponsive gels [130,[285][286][287][288] T g = 176 • C [289] (continued) e.g., T cp = 55-56 • C for M n = 17,000 g/mol and PDI = 1.84, whereas T cp = 48 • C for M n = 5000 g/mol and PDI = 1.47 (c p = 3 wt%) [297] A small hysteresis between the heating and cooling runs [297] T cp decreases upon increasing NaCl concentration [297] Chemically crosslinked hydrogel shrinks upon heating T cp ≈ 50−60 • C; collapse is not abrupt [207] Tacticity [223] Self assembling thermosensitive copolymers, e.g., block copolymers with poly(butyl acrylate) [294][295][296][297] …”

Section: List Of Thermoresponsive Homopolymersmentioning

confidence: 99%

Non-ionic Thermoresponsive Polymers in Water

Aseyev

Tenhu

Winnik

2010

Advances in Polymer Science

453

511

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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.

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Section: List Of Thermoresponsive Homopolymersmentioning

confidence: 99%

Non-ionic Thermoresponsive Polymers in Water

Aseyev

Tenhu

Winnik

2010

Advances in Polymer Science

453

511

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“…This was most likely due to the lower propagation rate constant for NIPMAm versus NIPAm, which would result in slower particle nucleation. 29 The total monomer concentration was increased to 140 mM to achieve a successful synthesis. Since the synthesis required a higher monomer concentration, the surfactant and initiator concentrations had to be further increased to attain a particle size near 50 nm in radius.…”

Section: Absorbance Measurementsmentioning

confidence: 99%

“…1, 2, 5, 7 Particles composed of poly(N-isopropylmethacrylamide) (pNIPMAm) behave in a similar manner, exhibiting an LCST around 44 °C, with the increased LCST arising from an increase in the rigidity of the pNIPMAm polymer, as is common for methacrylamides. [25][26][27][28][29] This behavior is important to this work due to the fact that our group has optimized core/shell nanogel synthesis techniques that utilize this LCST behavior to drive the controlled nucleation and growth of the particles.…”

Section: Introductionmentioning

confidence: 99%

Size-controlled synthesis of monodisperse core/shell nanogels

2007

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Small, monodispersed nanogels (~ 50-nm radius) were synthesized by free-radical precipitation polymerization and characterized using a suite of light scattering and chromatography methods. Nanogels were synthesized with either N-isopropylacrylamide or N-isopropylmethacrylamide as the main monomer, with acrylic acid or 4-acrylamidofluorescein as a co-monomer and N, N′-methylenebis(acrylamide) as a cross-linker. By varying the surfactant and initiator concentrations, particle size was controlled while maintaining excellent monodispersity. An amine-containing shell was added to these core particles to facilitate subsequent bioconjugation. Successful conjugation of folic acid to the particles was demonstrated as an example of how such materials might be employed in a targeted drug delivery system.

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“…The method of precipitation polymerization represents a widely investigated and elegant approach for the preparation of water swellable thermo-sensitive microgels. Especially Nisopropylacrylamide (NIPAAm) 43 or N-vinylcaprolactam (VCL) 44 are the most applied monomers. 45 In these cases, the enthalpic precipitation of growing oligoradicals occurs due to the unfavorable polymer-solvent interaction at high reaction temperatures.…”

Section: Microgels By Dispersion/precipitation Polymerizationmentioning

confidence: 99%

Light-Sensitive Polymeric Nanoparticles Based on Photo-Cleavable Chromophores

Klinger

2013

Springer Theses

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This thesis focuses on the design, synthesis and characterization of novel photo-sensitive microgels and nanoparticles as potential materials for the loading and light-triggered release/accessibility of functional compounds. In order to realize this concept, different approaches to irradiation-dependent response mechanisms have been investigated.Novel light-cleavable divinyl functionalized monomeric crosslinkers based on o-nitrobenzyl derivatives were synthesized and used for the preparation of either PMMA or hydroxyl functionalized PHEMA microgels swellable and degradable in organic solvents. By the introduction of anionic MAA moieties into the PHEMA microgels, this concept was successfully transferred to double stimuli-responsive p(HEMA-co-MAA) hydrogel nanoparticles exhibiting a pH-dependent swelling and light-induced degradation behavior in aqueous media. This sensitivity to two orthogonal triggers is proposed to combine a pHinduced post-formation loading mechanism with a pH-and light-triggered release. In addition, a new class of enzyme-and light-sensitive PAAm microgels based on (meth-)acrylate functionalized dextrans as photo-and enzymatically degradable macromolecular crosslinkers was developed by introducing a photo-labile linker between the enzymatically degradable dextran chain and the polymerizable vinyl moieties. Here, the water solubility of the crosslinkers is assumed to enable an in situ loading approach of hydrophilic compounds.A different approach to the loading of microgels is based on photo-labile covalent microgel-drug conjugates. The first step to the realization of this concept was achieved by the development of a novel functional monomer consisting of a doxorubicin molecule covalently attached to a radically polymerizable methacrylate group via a photo-cleavable linker.Moreover, in order to enable the release of hydrophobic substances in aqueous media, hydrophobic nanoparticles consisting of a photo-resist polymer were designed to be degradable upon irradiation in water. Light-triggered conversion of the initial hydrophobic polymer into hydrophilic PMAA induced in situ particle dissolution and release of nile red.Since the introduction of a stimuli-responsive shell around a microgel is assumed to prevent leakage of embedded compounds, studies on non-stimuli-responsive shell formation around preformed microgel seed particles and the formation of microgel cores in polymeric shells were conducted to investigate potential synthetic pathways to this approach.In a last attempt, the surface of PHEMA and p(HEMA-co-MAA) microgels was functionalized with cinnamoyl groups in order to trigger the (reversible) particles interaction with each other by light-induced [2+2] cycloaddition reactions.

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Preparation of poly(N‐isopropylmethacrylamide) latexes kinetic studies and characterization

Cited by 59 publications

References 0 publications

Non-ionic Thermoresponsive Polymers in Water

Non-ionic Thermoresponsive Polymers in Water

Size-controlled synthesis of monodisperse core/shell nanogels

Light-Sensitive Polymeric Nanoparticles Based on Photo-Cleavable Chromophores

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