scholarly journals Molecular Weight-Dependent, Flexible Phase Behaviors of Amphiphilic Block Copolymer/Additive Complexes in Aqueous Solution

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 178
Author(s):  
Jong Dae Jang ◽  
Young-Jin Yoon ◽  
Sang-Woo Jeon ◽  
Young Soo Han ◽  
Tae-Hwan Kim
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Phase Behavior ◽  
Optical Sensors ◽  
Face Centered Cubic ◽  
Wide Range ◽  
Pluronic Block Copolymer ◽  
Phase Behaviors

Pluronic amphiphilic block copolymers, well known to have a phase behavior can be controlled by external conditions, have a wide range of potential for applications such as nanotemplates or nanobuilding blocks. However, the phase behaviors of Pluronic block copolymer/additive complexes with highly ordered phases have not been fully investigated. Here, we report the unusual molecular weight-dependent self-assembly of Pluronic block copolymer/additive complexes. Depending on the temperature and additive, Pluronic P65 block copolymer with a lower molecular weight showed the closed loop-like (CLL) phase behavior with the disorder-order-disorder-order phase transition in aqueous solution, whereas Pluronic P105 and P85 block copolymers with higher molecular weights underwent highly ordered continuous phase transitions with face centered cubic (FCC), hexagonal, and lamellar phases. It is expected that the specific phase behavior of the block copolymer/additive complex can be applied in optical devices such as nanotemplates or optical sensors for a highly ordered superlattice. Furthermore, this study provides a new route to control the phase behavior of the block copolymers without a complicated process.

scholarly journals Block Copolymer Synthesis by the Combination of Living Cationic Polymerization and Other Polymerization Methods

2021 ◽  
Vol 9 ◽  
Author(s):  
Asmita Dey ◽  
Ujjal Haldar ◽  
Priyadarsi De
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Cationic Polymerization ◽  
Chemical Properties ◽  
Good Control ◽  
Vital Role ◽  
Living Cationic Polymerization ◽  
Wide Range ◽  
Post Modification

The foremost limitation of block copolymer synthesis is to polymerize two or more different types of monomers with different reactivity profiles using a single polymerization technique. Controlled living polymerization techniques play a vital role in the preparation of wide range of block copolymers, thus are revolutionary techniques for polymer industry. Polymers with good control over molecular weight, molecular weight distribution, chain-end functionality and architectures can be prepared by these processes. In order to improve the existing applications and create new opportunities to design a new block copolymer system with improved physical and chemical properties, the combination of two different polymerization techniques have tremendous scope. Such kinds of macromolecules may be attended by combination of homopolymerization of different monomers by post-modification techniques using a macroinitiator or by using a dual initiator which allows the combination of two mechanistically distinct techniques. This review focuses on recent advances in synthesis of block copolymers by combination of living cationic polymerization with other polymerization techniques and click chemistry.

Effect of Block Molecular Weight on the Mechanical Properties of PA1010-b-PEG Segmented Block Copolymers

2012 ◽  
Vol 512-515 ◽  
pp. 2127-2130
Author(s):  
Li Huo ◽  
Cai Xia Dong
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Microphase Separation ◽  
Soft Segment ◽  
Mechanical Measurements ◽  
Wide Range ◽  
Hard Block ◽  
Higher Temperature ◽  
Hard Segments

The mechanical properties were investigated of a series of PA-PEG thermalplastic elastomer based on PA1010 and polytetramethylene glycol (PEG) with varying hard and soft segment content. Dynamic mechanical measurements of these polymers have carried out over a wide range of temperatures. The block copolymers exhibit three peaks, designated as α, β and γ in the tanδ-temperature curve. The α transition shifts to higher temperature with increasing hard block molecular weight. However, at a constant hard molecular weight, the α transition shifts to higher temperature and the damping increases on increasing the soft segment molecular weight. DMA results show that the block copolymers exhibit a microphase separation structure and both soft and hard segments were found to be crystallizable. The degree of phase separation increases with increasing hard block molecular weight.

Basic Understanding of Phase Behavior and Structure of Silicone Block Copolymers and Surfactant–Block Copolymer Mixtures

2008 ◽  
pp. 391-417 ◽  
Author(s):  
Carlos Rodrguez ◽  
Arturo Lpez-Quintela ◽  
Md. Hemayet Uddin ◽  
Kenji Aramaki ◽  
Hironobu Kunieda
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Phase Behavior ◽  
Basic Understanding

Solvent Effects on the Synthesis of Polymeric Nanoparticles via Block Copolymer Self-Assembly Using Microporous Membranes

2020 ◽  
Vol 1000 ◽  
pp. 324-330
Author(s):  
Sri Agustina ◽  
Masayoshi Tokuda ◽  
Hideto Minami ◽  
Cyrille Boyer ◽  
Per B. Zetterlund
Keyword(s):  
Block Copolymer ◽  
Block Copolymers ◽  
Self Assembly ◽  
Polymeric Nanoparticles ◽  
Raft Polymerization ◽  
Membrane Emulsification ◽  
Membrane Pore ◽  
Novel Technique ◽  
Wide Range ◽  
Membrane Pore Size

The self-assembly of block copolymers has attracted attention for many decades because it can yield polymeric nanoobjects with a wide range of morphologies. Membrane emulsification is a fairly novel technique for preparation of various types of emulsions, which relies on the dispersed phase passing through a membrane in order to effect droplet formation. In this study, we have prepared polymeric nanoparticles of different morphologies using self-assembly of asymmetric block copolymers in connection with membrane emulsification. Shirasu Porous Glass (SPG) membranes has been employed as the membrane emulsification equipment, and poly (oligoethylene glycol acrylate)-block-poly (styrene) (POEGA-b-PSt) copolymers prepared via RAFT polymerization. It has been found that a number of different morphologies can be achieved using this novel technique, including spheres, rods, and vesicles. Interestingly, the results have shown that the morphology can be controlled not only by adjusting experimental parameters specific to the membrane emulsification step such as membrane pore size and pressure, but also by changing the nature of organic solvent. As such, this method provides a novel route to these interesting nanoobjects, with interesting prospects in terms of exercising morphology control without altering the nature of the block copolymer itself.

Synthesis of Polystyrene-B-Poly(Ethylene Oxide)monomethyl Ethermethacrylate Block Copolymers and its Self-Assembly in Aqueous Solution

2011 ◽  
Vol 284-286 ◽  
pp. 769-772
Author(s):  
Qian Qian You ◽  
Pu Yu Zhang
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Functional Group ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Ft Ir ◽  
A Chain

The block copolymer of PSt-b-POEOMA with the end of -COOH functional group has been synthesized by reversible addition fragmentation chain-transfer (RAFT) using S,S′-Bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate (BDATC) as a chain transfer agent. The architectures of the copolymers were confirmed by FT-IR and 1HNMR spectra. GPC analysis was used to estimate the molecular weight and the molecular weight distribution of the copolymers. Meanwhile, The nanostructures of the block copolymers PSt-b-POEOMA micelles formed in aqueous solution were observed by transmission electron microscopy (TEM) and dynamic light scattering (DLS).

New comonomer synthesis from thiophene-2-carbonyl chloride and cyclohexanone formaldehyde resin

2015 ◽  
Vol 44 (2) ◽  
pp. 79-86 ◽  
Author(s):  
Esin Ateş ◽  
Nilgün Kizilcan ◽  
Merve İstif
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Chemical Oxidation ◽  
Esterification Reaction ◽  
Formaldehyde Resin ◽  
Hydroxyl Groups ◽  
Content Type ◽  
Carbonyl Chloride ◽  
Oxidation System

Purpose – The purpose of this paper is to synthesise an electro-active monomer containing ketonic resins and then to investigate the redox reaction between Fe+3 and bound thiophene in comonomer. First, thiophene-functionalised ketonic resins were synthesised by esterification reaction of thiophene-2-carbonyl chloride (ThCCl) and hydroxyl groups of cyclohexanone formaldehyde resin (CFR). Thiophene-containing cyclohexanone formaldehyde resin (Th-CFR) was then polymerised by ferric salt. The structures of the specimens were characterised by means of Fourier transform infrared and Proton – Nuclear Magnetic Resonanse (1H-NMR) spectroscopy. Thermal properties of the samples were determined with differential scanning calorimeter. Molecular weights of the specimens were determined by gel permeation chromatography. The obtained samples were also characterised morphologically by scanning electron microscope. Design/methodology/approach – Synthesis of Th-CFR comonomers by a combination of condensation polymerization and chemical oxidation polymerisation processes is described. First, Th-CFR units were prepared by direct condensation reaction of thiophene-2-carbonyl chloride (ThCCl) and hydroxyl groups of CFR. Then, the chemical oxidation (CO) of Th-CFR in the presence of anhydrous iron (III) chloride salt (FeCl3) was performed in chloroform (CHCl3)/acetonitrile mixture solutions at room temperature. Findings – The important structural factor determined quantitatively for Th-CFR is the CFR/ThCCl ratio after reaction. The effect of the mole ratio effect of ThCCl and ketonic resin on the solubility, molecular weight, Tm and Tg values of the comonomers (Th-CFRs) were investigated. Research limitations/implications – The ferric ion (Fe+3) has a standard oxidation potential. Furthermore, FeCl3 can react with thiophene to produce a cation radical. FeCl3 cannot react with hydroxyl groups of ketonic resins. When ferric is used for in situ chemical oxidation application at relatively low temperatures (e.g. < 20°C), the oxidation reactions are usually less aggressive. Practical implications – This work provides technical information for the synthesis of conducting block copolymer and for the synthesis of chain-extended resins. The modified resins contain electro-active monomer as thiophene. The chemical oxidation system has been used to polymerise these thiophene groups and resins with much higher molecular weight might be produced. These resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating. Social implications – This will be used for the preparation of AB- and ABA-type block copolymers. These block copolymers may exhibit different properties due to incorporation of monomer into the block copolymer structure. Originality/value – Novel Th-CFR comonomers were synthesised. These comonomers have higher glass transition temperature (Tg) and melting temperature (Tm) value than CFR alone. The chemical oxidation system has been used to polymerise these thiophene-functionalised ketonic resins.

Self-Assembly of Block Copolymers for Photonic-Bandgap Materials

MRS Bulletin ◽  
2005 ◽  
Vol 30 (10) ◽  
pp. 721-726 ◽  
Author(s):  
Jongseung Yoon ◽  
Wonmok Lee ◽  
Edwin L. Thomas
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Photonic Crystals ◽  
Liquid Crystalline ◽  
Photonic Bandgap ◽  
Photonic Bandgap Materials ◽  
Periodic Microstructures ◽  
Self Assembled ◽  
Bandgap Materials

AbstractSelf-assembled block copolymer systems with an appropriate molecular weight to produce a length scale that will interact with visible light are an alternative platform material for the fabrication of large-area, well-ordered photonic-bandgap structures at visible and near-IR frequencies.Over the past years, one-, two-, and three-dimensional photonic crystals have been demonstrated with various microdomain structures created through microphase separation of block copolymers. The size and shape of periodic microstructures of block copolymers can be readily tuned by molecular weight, relative composition of the copolymer, and blending with homopolymers or plasticizers.The versatility of photonic crystals based on block copolymers is further increased by incorporating inorganic nanoparticles or liquid-crystalline guest molecules (or using a liquid-crystalline block), or by selective etching of one of the microdomains and backfilling with high-refractive-index materials. This article presents an overview of photonic-bandgap materials enabled by self-assembled block copolymers and discusses the morphology and photonic properties of block-copolymer-based photonic crystals containing nanocomposite additives.We also provide a view of the direction of future research, especially toward novel photonic devices.

Dielectric Behavior and Phase Behavior of Block Copolymer PEO13-PPO30-PEO13 Aqueous Solution

Langmuir ◽  
2018 ◽  
Vol 34 (19) ◽  
pp. 5574-5580
Author(s):  
Wantong Li ◽  
Juan Wang ◽  
Man Yang ◽  
Kongshuang Zhao
Keyword(s):  
Aqueous Solution ◽  
Block Copolymer ◽  
Phase Behavior ◽  
Dielectric Behavior

Wormlike Micelle Formation and Flow Alignment of a Pluronic Block Copolymer in Aqueous Solution

Langmuir ◽  
2007 ◽  
Vol 23 (13) ◽  
pp. 6896-6902 ◽  
Author(s):  
V. Castelletto ◽  
P. Parras ◽  
I. W. Hamley ◽  
P. Bäverbäck ◽  
J. Skov Pedersen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Block Copolymer ◽  
Micelle Formation ◽  
Wormlike Micelle ◽  
Pluronic Block Copolymer ◽  
Flow Alignment

Compatibility of Copolymers with Corresponding Homopolymers

1969 ◽  
Vol 42 (2) ◽  
pp. 447-461 ◽  
Author(s):  
G. Riess ◽  
J. Kohler ◽  
C. Tournut ◽  
A. Banderet
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Impact Strength ◽  
Methyl Methacrylate ◽  
Polymer Solutions ◽  
Random Copolymers ◽  
Ternary Diagrams ◽  
Two Systems

Abstract Since incompatibility of two homopolymers is the rule, it was of interest to see if mixing a corresponding copolymer (graft, block, or random) with a mixture of two incompatible homopolymers would bring about compatibility. For this study we limited ourselves to two systems of atactic polymers: polystyrene/poly (methyl methacrylate), and polystyrene/cis-l,4-polyisoprene since, in these systems, no crystallization occurs at normal temperatures. Investigation of these systems in the solid state—i.e., as films, prepared from polymer solutions by evaporation, enabled us to establish compatibility limits with considerable accuracy. The most important parameters for compatibility of homopolymer-copolymer mixtures seem to be, among other things: composition, molecular weight, and structure of the copolymers. Ternary diagrams for a mixture of two homopolymers and a copolymer show quite plainly that only block copolymers induce a certain compatibility. This is especially true when the polymer proportion in the block copolymers is approximately 50/50, and molecular weight of the homopolymers is substantially lower than that of the copolymer. Graft and random copolymers have little or no effect at all, upon compatibility. We also examined the relation between compatibility and impact strength for the system: polystyrene/polyisoprene/block copolymer.

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