Stereocomplex Formation of Densely Grafted Brush Polymers

Abstract

In this report, we explore the capability of macromolecules to interdigitate into densely grafted molecular brush copolymers. We demonstrate that by using the tendency for stereocomplexation between poly(l-lactide) and poly(d-lactide) as a driving force complementary linear polymers and brush copolymers can form a stereocomplex. However, stereocomplex formation between complementary brush copolymers is restricted and only partially observed when the side chains are of a critical molecular weight.

Dynamic Monte Carlo simulations of competition in crystallization of mixed polymers grafted on a substrate

“…Previously, Grubbs et al . observed that the stereocomplex formation between the brush PLLA and PDLA is restricted . But their densely grafted brush polymers are different from our grafted systems.…”

Nanostructures of Stereocomplex Polylactide in Poly(l-lactide) Doped with Poly(d-lactide)

“…The major principle of the stereocomplexation process includes two aspects, i.e., the specific molecular interaction as the driving force and the precise pairing of stereoisomers to keep it growing. The former was responsible for the preferential formation of sc ‐PLA at lower concentrations from solutions or at higher temperatures from the melt, while the latter rationalized the unique triangular single crystals and curvatures of dendritic and edge‐on crystals of sc ‐PLA as a result of unbalanced growths of stereoisomers with different molecular characteristics or amounts.…”

Alternating Placement of d‐ and l‐Alanine Moieties in the Polymer Side‐Chains

“…It happens when the interaction between the polymer chains of different configurations overcome the interaction between polymers with the same configuration . Generally an elevation of the melting temperature is found as a result of successful stereocomplex formation in DSC analysis . In the present work, the interactions between the side‐chains of the homopolymer as well as the copolymer are not strong enough to make them crystallizable as revealed by the absence of any melting temperature peak in the DSC thermogram.…”

“…The stereoisomers poly( l ‐lactide) and poly( d ‐lactide) can interact with each other to form such stereocomplexes . Recently, Grubbs and co‐workers reported that the interaction between poly( l ‐lactide) and poly( d ‐lactide) can act as a strong driving force to allowmacromolecules to form stereocomplexes . Also, Longo et al.…”

“…Existing literature suggests that, in general, two opposite enantiomeric polymeric structures are mixed in a solvent and the solvent is then allowed to evaporate slowly prior to the stereocomplex formation . As a consequence, stereoselective interaction occurs between two opposite enantiomeric polymer chains.…”