Polymers bearing dynamic covalent bonds may exhibit dynamic properties, such as self-healing, shape memory and environmental adaptation. However, most dynamic covalent chemistries developed so far require either catalyst or change of environmental conditions to facilitate bond reversion and dynamic property change in bulk materials. Here we report the rational design of hindered urea bonds (ure...

this is a report on the study of high melt flow, highly isotactic polypropylene homopolymer synthesized in liquid monomer using a fifth generation ziegler-natta catalytic system. at highest catalyst productivity, the response of thecatalyst to hydrogen as chain transfer is studied. melt flow rate is controlled by hydrogen as chain transfer from 0.4 to 300 g/10min with changing the amount of hyd...

Iso-selective initiators for the ring-opening polymerization (ROP) of rac-lactide are rare outside of Group 13. We describe the first examples of highly iso-selective lutetium initiators. The phosphasalen lutetium ethoxide complex shows excellent iso-selectivity, with a P(i) value of 0.81-0.84 at 298 K, excellent rates, and high degrees of polymerization control. Conversely, the corresponding L...

We employ Monte Carlo computer simulations to investigate the simultaneous controlled radical polymerization in solution and from a flat surface. The bulk polymers grow at faster rates and possess narrower molecular weight distribution than polymers initiated from flat, impenetrable surfaces. The rate of surface-initiated polymerization depends on the density of initiator sites. Our results pro...

Electrodeposited films of poly(ethylenedioxythiophene) (PEDOT) present a rough morphology and are wettable by water and oil. The covalent binding of low free energy fluorinated chains on the monomer before polymerization lowers the surface energy of the electroformed polymers sufficiently to give rise to superhydrophobic behaviour while conserving superoleophilicity. It holds the promise of an ...

In previous papers (1,2) the thermotropic properties and the kinetics of the bulk polymerization of the mesomorphic monomer cholesteryl acrylate have been described. In addition to cholesteryl acrylate, the methacrylate was prepared, as well as the respective acrylic methacrylic acid ester of cholestanol. We now wish to report the properties of these monomeric esters and the results of their po...

We introduce the fully reversible folding of single chain nanoparticles (SCNPs) based on covalent hetero Diels-Alder (HDA) chemistry. A cyclopentadiene (Cp)-protected cyanodithioester (CDTE) monomer is designed and copolymerized with methyl methacrylate (MMA) via RAFT polymerization. The polymer chains are folded and subsequently unfolded by exploiting the reversible nature of the HDA reaction.

A new type of nanocomposite hydrogels based on covalent cross-linked interactions with excellent mechanical properties and good stability has been prepared by using in situ free-radical polymerization; polystyrene nanoparticles with photo-activity are used as the cross-linking agent.