Aggregation behavior of poly(γ‐benzyl‐L‐glutamate)‐b‐polyisoprene‐b‐poly(γ‐benzyl‐L‐glutamate) rod‐coil‐rod triblock copolymer in N,N‐dimethylformamide

Abstract

Solution property of poly(γ‐benzyl‐L‐glutamate)‐b‐polyisoprene‐b‐poly(γ‐benzyl‐L‐glutamate) (GIG copolymer) was studied by using dynamic light scattering and static light scattering for N,N‐dimethylformamide (DMF) solution and DMF/toluene mixed solutions. GIG copolymer proved to aggregate in DMF and under DMF‐rich condition, that is, high‐polar region. The aggregate decreased in size, and completely disappeared under toluene‐rich condition, that is, low‐polar region. The correlation between solubility parameter and aggregate size of GIG copolymer in the DMF/toluene solution systems quantitatively demonstrated how strongly polarity caused by hydrogen bond made an impact on the aggregation behavior. Because the main driving force to the aggregation under DMF‐rich condition originates with polyisoprene (PIP) blocks, the aggregate in DMF is considered to be a core‐shell micelle consisting of flexible PIP core surrounded by rigid poly(γ‐benzyl‐L‐glutamate) (PBLG) shell. The values of dimensionless parameter ρ, defined as the ratio of radius of gyration 〈S2〉1/2 to hydrodynamic radius RH, revealed that a single chain of GIG copolymer had the form of rigid rod with flexibility, that is, once‐broken rod, caused by the incorporation of a flexible PIP chain between two rigid PBLG rods in the DMF/toluene solution system. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1740–1748, 2010

Dissipative Particle Dynamics Simulation on Self‐Assembly Behavior of Rod–Coil–Rod Triblock Copolymer in Solutions

“…As a typical rod‐like polypeptide, many kinds of block copolymers containing poly(γ‐benzyl‐ L ‐glutamate) (PBLG) are expected to be applied to biomaterials, such as GIG (G is PBLG and I is polyisoprene), and the biocompatibility of GIG depends highly on its order structure . Ogata et al investigated the correlation between solubility parameter and aggregate size of GIG copolymer in the different polar solutions. Additionally, Chen et al used self consistent field lattice techniques to study the phase behaviors of symmetrical rod–coil–rod triblock copolymer melt and found the different behaviors with the rod–coil diblock and coil–rod–coil triblock copolymers.…”

“…Recently, the linear rod-coil-rod triblock copolymers have been continually synthesized and their self-assemble order structures have been paid more and more attention. [24][25][26][27][28][29][30][31] Due to the excellent optoelectronic property of the p-conjugated rigid PPQ, Chen and Jenekhe [24] synthesized a PPQ-PS-PPQ rod-coil-rod triblock copolymer and found the spherical vesicle in a mixed solvent. Rahman et al [25] reported a rod-coil-rod copolymer consisting of poly(hexyl isocyanate) (PHIC) as helical rod block and poly(2-vinyl pyridine) (P2VP) as coil block.…”

“…Recently, the linear rod–coil–rod triblock copolymers have been continually synthesized and their self‐assemble order structures have been paid more and more attention . Due to the excellent optoelectronic property of the π‐conjugated rigid PPQ, Chen and Jenekhe synthesized a PPQ‐PS‐PPQ rod–coil–rod triblock copolymer and found the spherical vesicle in a mixed solvent.…”