Metal Catalyzed Polymerization: From Stereoregular Poly(α‐olefins) to Tailor‐Made Biodegradable/Biorenewable Polymers and Copolymers

Abstract

Metal catalyzed polymerizations are among the most important chemical reactions, accounting for the production of about 400 million tons per year of polymeric materials, 50 % of which are polyolefins. The CIRCC research units at the University of Salerno, founded by the late Professor Adolfo Zambelli, a coworker of Giulio Natta and a pioneer in the studies of stereospecific polymerization catalysts, has a consolidated expertise in this field. Although often considered a “mature” area of research, olefin polymerization catalysis continues to drive great interest of both industrial and academic scientists. On the other hand, strong political and economic pressure toward the development of “green” and possibly biodegradable alternatives to olefin‐based polymers stimulated our group to direct increasing research efforts in the area of sustainable polymers. In this perspective, we focus on the most recent work from the CIRCC research units involved in homogeneous catalysis for polymerization of a variety of monomers, with the aim to address how the concepts and the expertise developed for olefin polymerization can be applied to the development of different metal‐catalyzed polymerizations and copolymerizations. Of course, although the results are discussed in the frame of the most important literature contributions, a comprehensive review of such a wide and diversified topic is out of the scope of the paper. References to reviews covering the different types of metal catalyzed polymerizations are provided in each chapter.

Catalytic Main‐Group Metal Complexes of Phosphine‐Based Pincer Ligands

“…Conventionally, the ROP of cyclic esters is promoted by homoleptic metal alkoxides, such as tin(II) 2‐ethylhexanoate, which is used industrially [41] . Nevertheless, the inherent toxicity of tin compounds has driven the search for other main‐group metal catalysts for this type of reaction [42] .…”

“…Conventionally, the ROP of cyclic esters is promoted by homoleptic metal alkoxides, such as tin(II) 2-ethylhexanoate, which is used industrially. [41] Nevertheless, the inherent toxicity of tin compounds has driven the search for other main-group metal catalysts for this type of reaction. [42] In this section, we turn our attention to several phosphine-based pincer complexes of Li(I), Na(I), K(I), Mg(II), Ca(II), Zn(II) and Al(III), which have been demonstrated as active catalysts for the ROP of cyclic esters.…”