Monomer Substituent Effects in Catalytic Chain Transfer Polymerization: tert-Butyl Methacrylate and Dimethyl Itaconate

A machine-readable online database for rate coefficients in radical polymerization

An online database created and curated by an IUPAC subcommittee is introduced.

Controlled synthesis of methacrylate and acrylate diblock copolymers via end-capping using CCTP and FRP

This work demonstrates a method for preparing acrylic-methacrylic diblock copolymers via end-capping.

In situ stabilizer formation from methacrylic acid macromonomers in emulsion polymerization

Methacrylic acid oligomers containing a propenyl ω-endgroup were synthesized by CCTP and used as precursors to efficient stabilizers in surfactant-free emulsion polymerization.

Investigating the propagation kinetics of a novel class of nitrogen-containing methacrylates via PLP-SEC

The Mark–Houwink–Kuhn–Sakurada parameters as well as Arrhenius parameters of the propagation rate coefficient for a new group of nitrogen-containing methacrylates were determined via triple detector SEC and pulsed laser polymerization–size exclusion chromatography, respectively.

Entropy driven chain effects on ligation chemistry

We report the investigation of fundamental entropic chain effects that enable the tuning of modular ligation chemistry - for example dynamic Diels-Alder (DA) reactions in materials applications - not only classically via the chemistry of the applied reaction sites, but also via the physical and steric properties of the molecules that are being joined. Having a substantial impact on the reaction equilibrium of the reversible ligation chemistry, these effects are important when transferring reactions from small molecule studies to larger or other entropically very dissimilar systems. The effects on the DA equilibrium and thus the temperature dependent degree of debonding (%debond) of different cyclopentadienyl (di-)functional poly(meth-)acrylate backbones (poly(methyl methacrylate), poly(iso-butyl methacrylate), poly(tert-butyl methacrylate), poly(iso-butyl acrylate), poly(n-butyl acrylate), poly(tert-butyl acrylate), poly(methyl acrylate) and poly(isobornyl acrylate)), linked via a difunctional cyanodithioester (CDTE) were examined via high temperature (HT) NMR spectroscopy as well as temperature dependent (TD) SEC measurements. A significant impact of not only chain mass and length with a difference in the degree of debonding of up to 30% for different lengths of macromonomers of the same polymer type but - remarkably - as well the chain stiffness with a difference in bonding degrees of nearly 20% for isomeric poly(butyl acrylates) is found. The results were predicted, reproduced and interpreted via quantum chemical calculations, leading to a better understanding of the underlying entropic principles.