Introduction: Polymerization

Introduction: polymerization.

Introduction of abnormal N-heterocyclic carbene as an efficient organocatalyst: ring opening polymerization of cyclic esters.

The recently isolated abnormal N-heterocyclic carbene (aNHC) has been established as an efficient organocatalyst in ring opening polymerization of three different cyclic esters rac-lactide (rac-LA), ε-caprolactone (ε-CL), and δ-valerolactone (δ-VL). Preliminary DFT calculations indicate that aNHC can be a better organocatalyst than the corresponding nNHC counterpart.

Propene-cycloolefin polymerization

Highly active metallocenes and other single site catalysts have opened up the possibility of polymerizing cycloolefins such as norbornene (N) or of copolymerizing them with ethene (E) or propene (P). The polymers obtained show exciting structures and properties. E-N copolymers are industrially produced materials, with variable and high glass transitions depending on the wide range of their micr...

Polymerization Reactions

The tremendous growth of polymer production since the middle of the twentieth century has been intimately connected with the development of new types of catalysts, A notable example in this regard is the field of poly olefin materials, While catalysts are also used in the production of other types of polymers, the properties of most of these materials are not particularly dependent on the type ...

Polymerization Reactor

The principal difficulties in achieving good control of polymerization reactors are related to inadequate on-line measurement, a lack of understanding of the dynamics of the process, the highly sensitive and nonlinear behavior of these reactors, and the lack of well-developed techniques for the control of nonlinear processes. Some illustrations of these problems and a discussion of potential te...