Modeling Ethylene/Methyl Methacrylate and Ethylene/Methacrylic Acid Copolymers Using Acyclic Diene Metathesis Chemistry

Abstract

The synthesis, characterization, and thermal behavior of ADMET models of ethylene/methyl methacrylate (EMMA) and ethylene/methacrylic acid (EMAA) copolymers are described. These model copolymers exhibit sharper melting transitions and lower melting points relative to random copolymers made using chain-growth polymerization methods. The EMMA and EMAA model copolymers are compared with ADMET ethylene-based model copolymers reported previously, comparisons which support the earlier finding that melting points decrease with an increase in the steric bulk of the pendant group.

Noncovalent Hydrogen Bonds Tune the Mechanical Properties of Phosphoester Polyethylene Mimics

“…Two melting peaks were observed with P–OH functionality above 20%, which were reported for other polymers prepared by ADMET previously . The melting temperature increased significantly with more P–OH groups incorporated into the polymers.…”

“…Two melting peaks were observed with P–OH functionality above 20%, which were reported for other polymers prepared by ADMET previously. 26 The melting temperature increased significantly with more P–OH groups incorporated into the polymers. The crystallinity determined by differential scanning calorimetry (DSC) shows no clear trend with increasing H-bonding, and X-ray diffractograms (XRD) (Figure S27) revealed a similar degree of crystallinity and crystal structure for P(1-H x - co -2-H y ) (with y ≤ 0.4).…”

Precision Sulfonic Acid Ester Copolymers

“…[4,11] To circumvent similar hindered catalysis, the ethyl ester was incorporated into the monomer prior to polymerization (Scheme 1). Establishing the exact structural repeat into the single monomer allows for successful metathesis polycondensation and isolation of the final ethylene-covinyl sulfonic acid ethyl ester copolymer as an example.…”

Computational Insight into Catalytic Control of Poly(ethylene−methyl acrylate) Topology

“…[2][3][4][5] Defects in polymer microstructure that result from random branching induced by chain transfer reactions are known to have a significant effect on the polymer's crystallization and melting behavior (melting points are depressed with increasing steric bulk of such imperfections). [6][7][8] Theoretical studies performed on the already known catalytic systems can help in tailoring the coordination environment of the metal center in such a way as to obtain control over the molecular weight, molecular weight distribution, comonomer incorporation, and copolymer topology.…”