Approach to Formation of Multifunctional Polyester Particles in Controlled Nanoscopic Dimensions

Abstract

We present the synthesis of discrete functionalized polyester nanoparticles in selected nanoscale size dimensions via a controlled intermolecular chain cross-linking process. The novel technique involves the controlled coupling of epoxide functionalized polyesters with 2,2'-(ethylenedioxy)bis(ethylamine) to give well-defined nanoparticles with narrow size distribution and selected nanoscopic size dimensions. Diverse functionalized polyesters, synthesized with pendant functionalities via ring-opening copolymerization of delta-valerolactone with alpha-allyl-delta-valerolactone, alpha-propargyl-delta-valerolactone and 2-oxepane-1,5-dione, were prepared as linear precursors which facilitated 3-D nanoparticles with functionalities such as amines, keto groups, and alkynes for post modification reactions. We found that the nanoparticle formation and the control over the nanoscopic dimension is primarily influenced by the degree of the epoxide entity implemented in the precursor polymers and the amount of 2,2'-(ethylenedioxy)bis(ethylamine) as cross-linking reagent. The other functionalities in the linear polyester do not participate in the nanoparticle formation and particles with defined functionalities can be prepared from batches of identical linear polymers containing various functionalities or by mixing different polyester materials to achieve controlled amounts of specific functional groups. The utilization of integrated functionalities was demonstrated in one post-modification reaction with N-Boc-ethylenediamine via reductive amination. This work describes the development of a novel methodology to prepare functionalized well-defined 3-D nanoparticle polyester materials in targeted nanoscopic ranges with amorphous morphologies or tailored crystallinities that offer a multitude of utilizations as a result of their unique properties and control in preparation.

Nanosponge Formation from Organocatalytically Synthesized Poly(carbonate) Copolymers

“…Intramolecular 4,5 and interchain crosslinking processes 6,7 have been developed into suitable methods to form versatile supramolecular structures. In particular, intermolecular chain cross-linking of side-chainfunctional poly(ester)s derived by ring opening polymerization (ROP) of substituted δ-valerolactone monomers 8–11 affords controlled nanoparticle sizes that can be varied via the percentiles of side-chain functionalities into the linear poly(ester) precursor. Furthermore, the morphology and size can be controlled with the amount of difunctionalized cross-linking units, which react with the side-chain functionality of the polymer.…”

“…In comparison to thiolene-“click” reactions with analogous poly(ester) linear polymers 10 , the poly(carbonate)-derived particles are smaller than expected, attributed to a lower degree of polymerization of the poly(carbonate) copolymers (DP = 20) than those reported from the poly(ester) polymers and its analogs (DP = 50). 8 …”

The synthesis of a novel flame retardant and its synergistic efficiency in polypropylene/ammonium polyphosphate system

“…H-a was the characteristic peak of methyl connecting to Si-O-Si. [20] According to the characterization in the former research [21,22] H-c [21] and H-d [8] were assigned to the primary and secondary amine group. H-b, [22] H-e and H-f [8] were attributed to the different methylene groups, which were reported in the former papers.…”

Radical Copolymerization of Vinyl Ethers and Cyclic Ketene Acetals as a Versatile Platform to Design Functional Polyesters

“…[1,2] Nevertheless,s uch materials exhibited severe limitations because of their hydrophobic and/or semi-crystalline properties and absence of functionality,t hat could otherwise be used for tuning their physical properties or for the coupling with various molecules of interest. [6][7][8][9][10] Recently,elegant approaches were also developed to synthetize functionalized polyesters based on radical ring-opening copolymerization of cyclic ketene acetals (CKAs) with traditional vinyl monomers. [3][4][5] Fore xample,s ynthetic routes using functionalized lactones/carbonate prepared in many steps were copolymer-ized with traditional lactone/carbonate monomers,leading to abroad range of different biomaterials.…”