In situsynthesis of ABA triblock copolymer nanoparticles by seeded RAFT polymerization: Effect of the chain length of the third a block on the triblock copolymer morphology

Abstract

Synthesis of the ABA triblock copolymer nanoparticles of poly(N,N‐dimethylacrylamide)‐block‐polystyrene‐block‐poly(N,N‐dimethylacrylamide) (PDMA‐b‐PS‐b‐PDMA) by seeded RAFT polymerization is performed, and the effect of the introduced third poly(N,N‐dimethylacrylamide) (PDMA) block on the size and morphology of the PDMA‐b‐PS‐b‐PDMA triblock copolymer nanoparticles is investigated. This seeded RAFT polymerization affords the in situ synthesis of the PDMA‐b‐PS‐b‐PDMA core‐corona nanoparticles, in which the middle solvophobic PS block forms the compacted core, and the first solvophilic PDMA block and the introduced third PDMA block form the solvated complex corona. During the seeded RAFT polymerization, the introduced third PDMA block extends, and the molecular weight of the PDMA‐b‐PS‐b‐PDMA triblock copolymer linearly increases with the monomer conversion. It is found that, the size of the PS core in the PDMA‐b‐PS‐b‐PDMA triblock copolymer core‐corona nanoparticles is almost equal to that in the precursor of the poly(N,N‐dimethylacrylamide)‐block‐polystyrene diblock copolymer core‐corona nanoparticles and it keeps constant during the seeded RAFT polymerization, and whereas the introduction of the third PDMA block leads to a crowded complex corona on the PS core. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1777–1784

Alkoxyamine-functionalized latex nanoparticles through RAFT polymerization-induced self-assembly in water

“…The DLS analysis of latexes L2 and NMP-1 shown in Figure S7 indicates that the average diameter of nanoparticles increases from 50 to 72 nm. As recently reported, 33 this result may confirm that during the surface initiated polymerization a new PSSNa block is introduced initial triblock copolymer PAA-b-PS-b-PAA. As it can be seen in Figure 6, the effect of SSNa polymerization is noticeable in the morphology of latex considering different conversions.…”

Synthesis of multicompartment nanoparticles of a triblock terpolymer by seeded RAFT polymerization

“…[39][40][41][42][43] Following this seeded RAFT polymerization, a new block is introduced into the pre-prepared AB diblock copolymer nano-objects just as similarly as those in the graftthrough strategy to afford triblock copolymer nano-objects. 44 Recently, we have prepared ABA triblock copolymer corecorona particles following this seeded RAFT polymerization in the presence of the AB diblock copolymer nanoparticles.…”

“…The seed nanoparticles of the diblock copolymer of poly(N,Ndimethylacrylamide)-b-polystyrene trithiocarbonate (PDMA-b-PS-TTC, in which TTC represents the RAFT terminal of trithiocarbonate) were prepared by dispersion RAFT polymerization, 41,42 in which (1) the synthesis of the macro-RAFT agent of poly(N,N-dimethylacrylamide) trithiocarbonate (PDMA-TTC) by solution RAFT polymerization and (2) the PDMA-TTC macro-RAFT agent mediated dispersion polymerization to afford the diblock copolymer seed nanoparticles was included. The detailed procedures were introduced below.…”

Synthesis of Stimuli‐Responsive Block Copolymers and Block Copolymer Nano‐assemblies

“…To date, a number of BCP nano‐assemblies with different morphologies have already been prepared, including spheres, rods, vesicles, even some complex multicompartment nanostructures. [ 28‐58 ]…”

“…[ 28 ] It is found that in the synthesis of BCP nano‐assemblies following the PISA strategy by RAFT dispersion polymerization, an initial homogeneous polymerization and a subsequent heterogeneous polymerization are involved. Following this PISA strategy, nano‐assemblies of linear [ 29‐36 ] or star AB diblock copolymers, [ 37‐39 ] ABA [ 40‐41 ] or BAB [ 42‐43 ] triblock copolymers, ABC triblock copolymers, [ 44‐50 ] star ABC terpolymers, [ 51 ] the AB/A'B two diblock copolymer mixture, [ 52‐56 ] the AB/B diblock copolymer/homopolymer mixture [ 57 ] and the AB/BAB diblock copolymer/triblock copolymer mixture, [ 58 ] were synthesized, and their growth in particle size and evolution in particle morphology were investigated. To make smart or sensitive nano‐ assemblies, we designed several new thermo‐responsive [ 59‐66 ] and photo‐responsive polymers [ 67‐70 ] and the corresponding BCP nano‐ assemblies.…”