Self-Assembly Assisted Coupling of End Functional Block Copolymers

Zhu, Fangming; Ngai, To; Xie, Zuowei; Wu, Chi

doi:10.1021/ma030364m

Cited by 11 publications

(17 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The post-modification technique is easier to perform and can be used in various polymerization modes. [18][19][20] For post-modification approach, in order for…”

Section: Doi: 101002/marc201800479mentioning

confidence: 99%

“…The mechanistic transformations in which two or more mutually exclusive polymerization techniques that are either combining sequentially or concurrently, allowing the incorporation of different types of monomers can be realized by two main approaches: i) post‐modification technique and ii) dual functional initiator approach. The post‐modification technique is easier to perform and can be used in various polymerization modes . For post‐modification approach, in order for the second polymerization mode to proceed it is necessary for a reactive functional group to be introduced during the initiation or the termination steps of the polymerization of the first monomer.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Polymer Synthesis with More Than One Form of Living Polymerization Method

Guo

Choi

Feng

et al. 2018

Macromol. Rapid Commun.

View full text Add to dashboard Cite

Controlled radical polymerization (CRP) or controlled/living radical polymerization has revolutionized the polymer industry as a tool for the preparation of a wide variety of polymers. This process enables the preparation of polymers with good control of molecular weight, narrow polydispersity, and a range of architectures including block and graft copolymers, star polymers, and other functional polymers. The mechanistic transformation reaction provides a great opportunity to tune chemical and physical properties of copolymers. It can be applied to combine different homopolymers using post‐modification techniques or by the use of a dual initiator, allowing the combination of mechanistically distinct polymerization reactions. This review will cover CRP transformations including the synthesis of block copolymers with both linear structures (AB, ABA, (AB) n , multiblocks, etc.) and branched macromolecular architectures (graft, miktoarm star, and dendritic‐like), which are obtained by a combination of more than one form of living polymerization reaction.

show abstract

“…The post-modification technique is easier to perform and can be used in various polymerization modes. [18][19][20] For post-modification approach, in order for…”

Section: Doi: 101002/marc201800479mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Polymer Synthesis with More Than One Form of Living Polymerization Method

Guo

Choi

Feng

et al. 2018

Macromol. Rapid Commun.

View full text Add to dashboard Cite

show abstract

“…To solve this problem, one can use initiators containing two types of functional groups capable of initiating each of these processes in parallel and independently [ 4 , 5 ]. Second approach is introduction of a functional group that initiates the polymerization of the second monomer at the stage of initiation or termination of the first monomer polymerization (post-modification) [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

Molecular Brushes with a Polyimide Backbone and Poly(ε-Caprolactone) Side Chains by the Combination of ATRP, ROP, and CuAAC

et al. 2021

View full text Add to dashboard Cite

An approach to the synthesis of the novel molecular brushes with a polyimide (PI) backbone and poly(ε-caprolactone) (PCL) side chains was developed. To obtain such copolymers, a combination of various synthesis methods was used, including polycondensation, atom transfer radical polymerization (ATRP), ring opening polymerization (ROP), and Cu (I)-catalyzed azide-alkyne Huisgen cycloaddition (CuAAC). ATRP of 2-hydroxyethyl methacrylate (HEMA) on PI macroinitiator followed by ROP of ε-caprolactone (CL) provided a “brush on brush” structure PI-g-(PHEMA-g-PCL). For the synthesis of PI-g-PCL two synthetic routes combining ROP and CuAAC were compared: (1) polymer-analogous transformations of a multicenter PI macroinitiator with an initiating hydroxyl group separated from the main chain by a triazole ring followed by ROP of CL, or (2) a separate synthesis of macromonomers with the desirable functional groups (polyimide with azide groups and PCL with terminal alkyne groups), followed by a click reaction. Results showed that the first approach allows to obtain graft copolymers with a PI backbone and relatively short PCL side chains. While the implementation of the second approach leads to a more significant increase in the molecular weight, but unreacted linear PCL remains in the system. Obtained macroinitiators and copolymers were characterized using 1H NMR and IR spectroscopy, their molecular weight characteristics were determined by SEC with triple detection. TGA and DSC were used to determine their thermal properties. X-ray scattering data showed that the introduction of a polyimide block into the polycaprolactone matrix did not change the degree of crystallinity of PCL.

show abstract

“…In principle, it should make the interchain coupling much easier. Previously, we have successfully prepared multiblock (A–B–A) n copolymers by the self-assembly assisted polypolymerization (SAAP) of A–B–A triblock precursors with one reactive group at one end of A-block in a solvent selectively poor for the middle B-block so that the two reactive groups are concentrated and forced to stick out on the periphery. − Similarly, the multiblock (PEO–PPO-PEO) 5 was prepared by concentrating the azide and alkyne groups of equimolar N 3 –PEO - b - PPO - b - PEO-N 3 and HCC-PEO - b - PPO - b - PEO-CCH chains on the periphery in water, a solvent selectively poor for the PPO block at higher temperature . We also prepared the multiblock (PI–PS–PI) 30 using esterification between diamine and diacyl chloride groups in n -hexane, a solvent selectively poor for PS .…”

Section: Introductionmentioning

confidence: 99%

Self-Assembly Assisted Polypolymerization (SAAP) of Diblock Copolymer Chains with Two Reactive Groups at Its Insoluble End

Yan

Zhang

et al. 2013

Macromolecules

Self Cite

View full text Add to dashboard Cite

Preparation of diblock copolymers, (≡,N3)-poly(N-isopropylacrylamide)-b-poly(N,N-dimethylacrylamide) [(≡,N3)-PNIPAM-b-PDMA] and (≡,N3)-polystyrene-b-PNIPAM [(≡,N3)-PS-b-PNIPAM], with reactive alkyne and azide at one end using a trifunctional agent enables us to study how their self-assembly in a selective solvent affects interchain coupling, i.e., the self-assembly assisted polypolymerization (SAAP). As expected, (≡,N3)-PNIPAM-b-PDMA chains self-assemble into a micelle-like core–shell structure with a PNIPAM core in water at 50 °C. The coupling of as many as 17 PNIAPM ends together led to star-like chains, independent of the copolymer concentration, while the coupling efficiencies at lower temperatures (with no self-assembly) and in good solvents are much lower. These star-like chains remember their “birth” state in water and undergo the intrachain contraction to form single-chain micelles instead of large multichain aggregates. On the other hand, (≡,N3)-PS-b-PNIPAM exists as individual chains in THF, a mixture of unimers and micelles in 2-propanol, the core–shell micelles in methanol, and irregular aggregates in water. Only in methanol, the coupling efficiency is notably improved. The addition of water into 2-propanol enhances the self-assembly and so does the interchain coupling. The current study shows that even the solvophobic interaction makes the insoluble blocks less mobile inside the core and decreases the collision probability of reactive chain ends, the self-assembly still concentrates the reactive ends together and assists the coupling if the selective solvent is properly chosen.

show abstract

Self-Assembly Assisted Coupling of End Functional Block Copolymers

Cited by 11 publications

References 16 publications

Polymer Synthesis with More Than One Form of Living Polymerization Method

Polymer Synthesis with More Than One Form of Living Polymerization Method

Molecular Brushes with a Polyimide Backbone and Poly(ε-Caprolactone) Side Chains by the Combination of ATRP, ROP, and CuAAC

Self-Assembly Assisted Polypolymerization (SAAP) of Diblock Copolymer Chains with Two Reactive Groups at Its Insoluble End

Contact Info

Product

Resources

About