RAFT synthesis, properties and morphologies via thermal annealing of new azo-based ABA triblock copolymers bearing rigid and soft segments

Zenati, Athmen; Thammalangsy, Soulighothai

doi:10.1080/1023666x.2019.1649056

Cited by 4 publications

(13 citation statements)

References 71 publications

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“…The thermal characteristics of the prepared TBCs are in accordance with the thermal properties published previously. 70,91 3.3. Nanostructures in Thin Triblock Copolymer Films.…”

Section: Synthesis and Characterization Of Triblockmentioning

confidence: 99%

“…20 Unlike chemically cross-linked polymer, BC having both thermoplastic and elastomeric properties can withstand great deformation without breaking its chemical bonds when it melts or dissolves in suitable solvents. 70,71 This type of BC is usually synthesized by the conventional technique of free-radical polymerization (FRP). 72−74 FRP allows the formation of BC with less control over its molecular weights and architecture, which are primarily responsible for the physical properties of BC.…”

Section: Introductionmentioning

confidence: 99%

“…Ultimately, we compare the obtained results to those found in previously reported studies, including our work where a series of triblock copolymers were synthesized using PEG and poly(methyl methacrylate) as soft blocks while PDOPAM and poly(2-[2-(4-cyano-azobenzene-4′-oxy)ethylene-oxy]ethyl methacrylate) with a pendent cyanoterphenyl group as rigid segments. 70,85,86 2. EXPERIMENTAL SECTION 2.1.…”

Section: Introductionmentioning

confidence: 99%

“…86 The M n (NMR) values are estimated according to the formula reported in the Supporting Information and the literature. 70 The conversion of the DOPAM monomer into PDOPAM blocks is varied from 35 to 83%. Polymerization of the DOPAM monomer in the anisole solvent (20 wt %) is carried out at 70 °C for 24 h. AIBN (0.025 g, 0.0151 mmol).…”

Section: Introductionmentioning

confidence: 99%

“…The solution is diluted with THF (2 mL) and dripped into methanol (200 mL) to precipitate the polymer. 70 The resulting triblock copolymer is collected by filtration and dried in a vacuum oven at room temperature for 24 h to remove moisture. A 52% conversion is determined by GPC for the DOPAM monomer.…”

Section: Introductionmentioning

confidence: 99%

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Thermal Properties and Self-Assembly Behaviors of Triblock Copolymers Consisting of PEG Segment and Acrylamide-Based Block Bearing Alkyl Side Chains Prepared by RAFT Method

2021

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A new series of hybrid triblock copolymers (TBCs) based on hard−soft−hard segments are synthesized by reversible addition−fragmentation chain transfer (RAFT) polymerization using a macroinitiator poly(ethylene glycol) (PEG) macromolecular chain transfer agent (macro-CTA) and monomer p-dodecylphenyl-N-acrylamide (DOPAM). The resulting TBCs are characterized and evaluated by 1 H NMR, gel permeation chromatography, and differential scanning calorimetry. Kinetic studies on triblock copolymerization indicated the controlled/living characteristic of RAFT polymerization with good distribution of molecular weight (M w /M n ≤ 1.39). All TBCs exhibited two melting temperatures (T m ) at 50 and 240 °C unlike PEG macro-CTA, which revealed a single T m at 50 °C. However, TBC-4 and TBC-5 showed strong T m (PDOPAM) peaks compared to TBC-1, TBC-2, and TBC-3, mainly due to the increase in the volume fraction of PDOPAM. Morphologies of TBCs are studied by atomic force microscopy and grazing incidence small-angle X-ray scattering. TBCs (TBC-2, TBC-4, and TBC-5) with different blocks ratios (f PDOPAM ≠ f PEG ) formed cylindrical phases, in particular TBC-5 containing a higher PDOPAM ratio (72%) generated a highly ordered cylindrical nanostructure. Contrastingly, TBC-3 with nearly the same length of PDOPAM (49%) and PEG (51%) self-assembled into the lamellar phase.

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“…The thermal characteristics of the prepared TBCs are in accordance with the thermal properties published previously. 70,91 3.3. Nanostructures in Thin Triblock Copolymer Films.…”

Section: Synthesis and Characterization Of Triblockmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermal Properties and Self-Assembly Behaviors of Triblock Copolymers Consisting of PEG Segment and Acrylamide-Based Block Bearing Alkyl Side Chains Prepared by RAFT Method

2021

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Properties and molecular self‐assembly of liquid crystalline hard–hard diblock and hard–soft–hard triblock copolymers influenced by Flory–Huggins interaction parameter and volume fraction of distinct segments

Zenati¹,

Pokhrel

2023

Journal of Polymer Science

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Two series of hybrid liquid crystalline (LC) diblock copolymers (DBCs) and triblock copolymers (TBCs) composed of hard and soft blocks with great control over their molecular masses, dispersities (Mw/Mn = Đ ≤ 1.38) and compositions were prepared via reversible addition‐fragmentation chain transfer polymerization in anisole solvent using new p‐dodecylphenyl‐N‐acrylamide monomer, azobisisobutyronitrile initiator, poly(2‐[2‐(4‐cyano‐azobenzene‐4‐oxy)ethylene‐oxy]ethyl methacrylate) and poly(2‐[2‐(4‐cyano‐azobenzene‐4‐oxy)ethylene‐oxy]ethyl methacrylate)‐block‐poly(n‐butyl methacrylate) macroinitiators. Structures and properties of BCs were characterized by proton nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimeter, optical polarizing microscope, atomic force microscope and grazing‐incidence small angle X‐ray scattering. Kinetic behavior indicated that block copolymerization proceeded with controlled/living characteristics. Every BCs revealed three endothermic transitions corresponding to glassy phase transition, smectic‐to‐nematic phase transition (TS‐N) and melting phase transition. DBC‐1, DBC‐2, TBC‐1 and TBC‐2 with high‐LC volume fractions exhibited strong TS‐N contrasted to DBC‐3, DBC‐4, TBC‐3 and TBC‐4 having low‐LC contents. DBC‐1, DBC‐2, DBC‐3, TBC‐1 and TBC‐2 evidenced smectic C structure while TBC‐3 containing low‐LC segment (39 wt%) showed nematic structure. Morphologies of block copolymer thin films in mixed solvent (Tetrahydrofuran/cyclohexane) vapor annealing system varied significantly, depending on the volume fractions of building blocks and the interactions between the blocks and solvents.

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Synthesis, characteristics and thermally induced self-assembly of silicon-based thermo/photo-responsive block copolymers prepared from monomer bearing paired side-chain azo mesogens using RAFT process

Zenati,

Koirala

2025

Polymer

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RAFT synthesis, properties and morphologies via thermal annealing of new azo-based ABA triblock copolymers bearing rigid and soft segments

Cited by 4 publications

References 71 publications

Thermal Properties and Self-Assembly Behaviors of Triblock Copolymers Consisting of PEG Segment and Acrylamide-Based Block Bearing Alkyl Side Chains Prepared by RAFT Method

Thermal Properties and Self-Assembly Behaviors of Triblock Copolymers Consisting of PEG Segment and Acrylamide-Based Block Bearing Alkyl Side Chains Prepared by RAFT Method

Properties and molecular self‐assembly of liquid crystalline hard–hard diblock and hard–soft–hard triblock copolymers influenced by Flory–Huggins interaction parameter and volume fraction of distinct segments

Synthesis, characteristics and thermally induced self-assembly of silicon-based thermo/photo-responsive block copolymers prepared from monomer bearing paired side-chain azo mesogens using RAFT process

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