No abstract

A variety of exact graft copolymers, such as poly(tert-butyl methacrylate)-exact graft-polystyrene (PS), poly(ferrocenylmethyl methacrylate)-exact graft-PS, and poly(2-vinylpyridine)-exact graft-PS, have been successfully synthesized by developing a novel stepwise iterative methodology based on a new concept utilizing living in-chain-(3-tert-butyldimethylsilyloxymethylphenyl) (SiOMP)-functionalized AB diblock copolymers as key building blocks. The methodology basically involves three reaction steps in each iterative process, i.e., (1) living anionic block copolymerization to prepare a living in-chain-SiOMP-functionalized AB diblock copolymer, (2) a transformation reaction of the SiOMP group into an α-phenyl acrylate (PA) function, and (3) a 1:1-addition reaction of the resulting in-chain-PA-functionalized AB diblock copolymer with a living in-chain-SiOMP-functionalized AB diblock copolymer separately prepared to link the two block copolymer chains. By performing the same iterative process involving steps 1–3 several times, the above-mentioned exact graft copolymers having three to five PS branches were synthesized. The resulting polymers were all well-defined in architecture and precisely controlled in chain structure.

The current state-of-the-art mixing strategies of nanoparticles with insulating polymeric components have only partially utilized the unique electrical conductivity of graphene in nanocomposite systems. Herein, this paper reports a nonmixing method of direct creation of polymer/graphene nanocomposites from polymer blends via laser irradiation. Polycarbonate-laser-induced graphene (PC-LIG) nanocomposite is produced from a PC/polyetherimide (PC/PEI) blend after exposure to commercially available laser scribing with a power of ≈6 W and a speed of ≈2 cm s . Extremely high electrical conductivities are obtained for the PC-LIG nanocomposites, ranging from 26 to 400 S m , depending on the vol% of the starting PEI phase in the blend. To the authors' knowledge, these conductivity values are at least one order of magnitude higher than the values that are previously reported for conductive polymer/graphene nanocomposites prepared via mixing strategies. The comprehensive microscopy and spectroscopy characterizations reveal a complete graphitization of the PEI phase with columnar microstructure embedded in the PC phase.

In order to synthesize miktoarm star-branched polymers consisting of poly(2-(perfluorooctyl)ethyl methacrylate) (P(F 8 H 2 -MA)) segments insoluble in most organic solvents, a novel methodology based on a new concept by using a THF-soluble in-chain-benzyl bromide (BnBr)-functionalized AB diblock copolymer, polystyrene (PS)-block-P(F 8 H 2 -MA), as a key building blocks is proposed. The methodology involves the following three reaction steps: (1) preparation of in-chain-(3-tert-butyldimethylsilyloxymethylphenyl) (SiOMP)-functionalized PS-block-P(F 8 H 2 -MA) by means of living anionic polymerization, (2) a transformation reaction of the SiOMP group into BnBr function, and (3) a coupling reaction of the resulting in-chain-BnBr-functionalized PS-block-P(F 8 H 2 -MA) with another living anionic polymer(s). With this methodology, a variety of well-defined 3-arm ABC, 4-arm A 3 B, ABC 2 , and ABCD miktoarm star-branched polymers consisting of P(F 8 H 2 -MA) (B) segments was successfully synthesized. Thus, the proposed methodology satisfactorily works and opens a new route for the synthesis of miktoarm star-branched polymers consisting of insoluble arm segment(s).