scholarly journals Solubilization of Phenol Derivatives in Polymer Micelles Formed by Cationic Block Copolymer

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Irma Fuentes ◽  
Patricio Silva ◽  
Francisco Martinez ◽  
Andrés F. Olea
Keyword(s):  
Block Copolymers ◽  
Partition Coefficients ◽  
Diblock Copolymers ◽  
Polymer Micelles ◽  
Phenol Derivatives ◽  
Fluorescence Probing ◽  
Region Model ◽  
Spherical Micelles ◽  
Self Aggregation ◽  
Side Alkyl Chain

The aggregation of cationic block copolymers formed by polystyrene (PS) and poly(ethyl-4-vinylpyridine) (PS-b-PE4VP) was studied in aqueous solution. Diblock copolymers of PS and poly(4-vinylpyridine) were synthesized by sequential anionic polymerization using BuLi as initiator. Subsequently, the 4-vinylpyridine units were quaternized with ethyl bromide to obtain cationic PS-b-PE4VP block copolymers with different quaternization degree. The self-aggregation of cationic block copolymers was studied by fluorescence probing, whereas the morphology and size of polymer micelles were determined by transmission electronic microscopy. Results indicate that spherical micelles with sizes lower than 100 nm were formed, whereas their micropolarity decreases with increasing quaternization degree. The partition of phenols between the micellar and aqueous phase was studied by using the pseudo-phase model, and the results show that the partition coefficients increase with increasing length of the side alkyl chain and are larger for star micelles. These results are discussed in terms of three-region model.

Effect of long-range order on craze microstructure in deformed PS/PB block copolymers

1987 ◽  
Vol 45 ◽  
pp. 524-525
Author(s):  
Chris S. Henkee ◽  
Edwin L. Thomas
Keyword(s):  
Block Copolymers ◽  
Diblock Copolymers ◽  
Local Deformation ◽  
Long Range Order ◽  
Diamond Structure ◽  
Volume Percent ◽  
Craze Growth ◽  
Stage Process ◽  
Spherical Micelles ◽  
Double Diamond

The morphology present in block copolymers is determined by the volume percent of each of the components present. When the minority component ranges from 0-20 vol%, spherical micelles of the minority component are found. From 20-35 vol%, cylindrical microdomains are observed; at volume fractions slightly greater than this (35-38%), the ordered bicontinuous double diamond structure is observed. Finally from 38-≃60 vol%, regular alternating lamellae are found. It is now well known that for polystyrene-polybutadiene (PS/PB) diblock copolymers in which the PB is the minority component forming either spheres or cylinders, that deformation takes place via crazing. The mechanism for craze growth in these polymers appears to be a two stage process; the cavitation of the PB phase, followed by the drawing of the PS matrix into fibrils spanning the region of local deformation.

Mechanical and Structural Consequences of Associative Dynamic Cross-Linking in Acrylic Diblock Copolymers

2019 ◽  
Author(s):  
Jacob Ishibashi ◽  
Yan Fang ◽  
Julia Kalow
Keyword(s):  
Block Copolymers ◽  
Rheological Properties ◽  
Diblock Copolymers ◽  
Cross Linking ◽  
Statistical Copolymer

<p>Block copolymers are used to construct covalent adaptable networks that employ associative exchange chemistry (vitrimers). The resulting vitrimers display markedly different nanostructural, thermal and rheological properties relative to those of their statistical copolymer-derived counterparts. This study demonstrates that prepolymer sequence is a versatile strategy to modify the properties of vitrimers.</p>

Amphiphilic Diblock Copolymers of Poly(glycidol) with Biodegradable Polyester/Polycarbonate. Organocatalytic One-Pot ROP and Self-Assembling Property

2021 ◽  
Author(s):  
Tingyu He ◽  
Atsushi Narumi ◽  
Yanqiu Wang ◽  
Liang Xu ◽  
Shin-ichiro Sato ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Diblock Copolymers ◽  
Amphiphilic Block Copolymers ◽  
Synthetic Method ◽  
Biodegradable Polyester ◽  
One Pot ◽  
Self Assembling ◽  
Amphiphilic Diblock Copolymers

A synthetic method for a series of poly(glycidol) (PG)-based amphiphilic block copolymers is presented with an emphasis on the catalyst switch method from an organic superbase (t-Bu-P4) to another with...

Self-crosslinking assemblies with tunable nanostructures from photoresponsive polypeptoid-based block copolymers

2020 ◽  
Vol 11 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Jirui Wei ◽  
Jing Sun ◽  
Xu Yang ◽  
Sifan Ji ◽  
Yuhan Wei ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Diblock Copolymers ◽  
New Family

A series of reversible crosslinking assemblies with tunable morphologies are obtained from a new family of photoresponsive polypeptoid-based diblock copolymers.

Synthesis, characterization and association behavior of linear-dendritic amphiphilic diblock copolymers based on poly(ethylene oxide) and a dendron derived from 2,2′-bis(hydroxymethyl)propionic acid

2015 ◽  
Vol 6 (12) ◽  
pp. 2274-2282 ◽  
Author(s):  
Weiwei Zhang ◽  
Weiwei Jiang ◽  
Delong Zhang ◽  
Guangyue Bai ◽  
Pengxiao Lou ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Ethylene Oxide ◽  
Propionic Acid ◽  
Diblock Copolymers ◽  
Association Behavior ◽  
Poly Ethylene Oxide ◽  
Amphiphilic Diblock Copolymers ◽  
Poly Ethylene

Two new amphiphilic linear-dendritic block copolymers have been synthesized and characterized. And their association behaviors have also been studied.

Dilute Solutions of Block Copolymers. 1. Diblock Copolymers

1998 ◽  
Vol 31 (13) ◽  
pp. 4342-4349 ◽  
Author(s):  
O. F. Olaj ◽  
B. Neubauer ◽  
G. Zifferer
Keyword(s):  
Block Copolymers ◽  
Diblock Copolymers ◽  
Dilute Solutions

scholarly journals A controlled synthesis method of alkyl methacrylate block copolymers via living anionic polymerization at ambient temperature

RSC Advances ◽  
2019 ◽  
Vol 9 (28) ◽  
pp. 16049-16056 ◽  
Author(s):  
Zheng Li ◽  
Jianding Chen ◽  
Guijin Zou ◽  
Tongyuan Zhang ◽  
Dafu Wei ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Ambient Temperature ◽  
Anionic Polymerization ◽  
Diblock Copolymers ◽  
Synthesis Method ◽  
Controlled Synthesis ◽  
Living Anionic Polymerization ◽  
Alkyl Methacrylate ◽  
High Yields

A series of well-defined diblock copolymers containing PMMA, PEMA and PBMA blocks were synthesized with narrow MWDs and high yields via anionic polymerization, while t-BuOK was selected as initiator in THF at 0 °C. .

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