Polymerization of β‐pinene with Schiff‐base nickel complexes catalyst: Synthesis of relatively high molecular weight poly(β‐pinene) at high temperature with high productivity

Abstract

A series of easily accessible and stable Schiff‐base nickel complexes (complex 1–4) in conjunction with methylaluminoxane (MAO) were employed for the synthesis of relatively high molecular weight β‐pinene polymers at high temperature with high productivity. The ligand structure of the complex had a substantial effect on the polymerization in terms of the productivity and the molecular weight. With complex 4 in the presence of MAO, high molecular weight polymers of β‐pinene (Mn ∼ 10,900) were obtained at 40 °C with an extremely high productivity up to 1.25 × 107 g polyβ‐pinene/mol of Ni. 1H NMR analyses showed that the obtained β‐pinene polymer was structurally identical to that formed by conventional cationic Lewis acid initiators. The polymerization was presumably initiated by the nickel cation formed by the reaction of the schiff‐base nickel complex and MAO, while the propagation proceeded in a manner typical for a conventional carbocationic polymerization process. Direct evidence for the carbocationic polymerization was offered by the fact that quenching of the polymerization with methanol at a low monomer conversion resulted in incorporation of a methoxyl end group into the polymer chain. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3739–3746, 2007

Pinenes: Abundant and Renewable Building Blocks for a Variety of Sustainable Polymers

“…[38][39][40][41][42] These bicyclicc ompounds are thus the most abundant naturally occurring terpenes that can be obtained from non-edible parts of plants in many tons. Accordingly,a pplications of classical cationic or radical polymerization of pinenes for the preparation of aliphatic cycloolefin polymers have been described for decades [45][46][47][48][49][50][51][52] and also different copolymerizations were studied in detail. Commercial polymers of these compounds,"terpene resins", are normally obtained by Lewis acid-catalyzed polymerization.…”

“…[43,44] They find applications for example,a sa dhesives or additives in rubber. Accordingly,a pplications of classical cationic or radical polymerization of pinenes for the preparation of aliphatic cycloolefin polymers have been described for decades [45][46][47][48][49][50][51][52] and also different copolymerizations were studied in detail. [53][54][55][56][57][58] Furthermore,a dvanced polymerization strategies and also different functionalizations of the double bonds of pinenes can be performed for the preparation of av ariety of different monomers and polymers (Scheme 1A), which is highlighted in the following paragraphs.F urthermore, considering the immense potential of catalytic upgrading of pinenes, [35] suchlike approaches are very likely to gain increasing impact in the near future.…”

Pinene: reichlich vorhandene und erneuerbare Bausteine für eine Vielzahl an nachhaltigen Polymeren

“…Innerhalb dieser molekularen Biomasse kçnnen vier große Gruppen unterschieden werden, nämlich Sauerstoff-reiche Biomasse,K ohlenwasserstoff-reiche Biomasse,K ohlenwasserstoff-Biomasse und Nicht-Kohlenwasserstoff-Biomasse. Dementsprechend wurden Anwendungen zur klassischen kationischen oder radikalischen Polymerisation von Pinenen zur Herstellung von aliphatischen cycloolefinischen Polymeren schon seit Jahrzehnten beschrieben, [45][46][47][48][49][50][51][52] und auch verschiedene Copolymerisationen wurden im Detail untersucht. [27][28][29][30][31][32][33][34][35][36][37] Innerhalb dieser Substanzklasse wurden insbesondere in den letzten paar Jahren signifikante Fortschritte mit den isomeren Monoterpenen a-Pinen und b-Pinen erzielt (Schema 1A;esgibt auch noch weitere Isomere).…”

“…B. als Klebstoffe oder Additive in Gummi. Dementsprechend wurden Anwendungen zur klassischen kationischen oder radikalischen Polymerisation von Pinenen zur Herstellung von aliphatischen cycloolefinischen Polymeren schon seit Jahrzehnten beschrieben, [45][46][47][48][49][50][51][52] und auch verschiedene Copolymerisationen wurden im Detail untersucht. [53][54][55][56][57][58] Zusätzlich dazu kçnnen fortschrittliche Polymerisationsstrategien und auch verschiedene Funktionalisierungen der Doppelbindungen von Pinenen zur Herstellung einer Vielzahl verschiedener Monomere und Polymere durchgeführt werden (Schema 1A), was in den folgenden Abschnitten herausgehoben wird.…”

Progress in the synthesis of sustainable polymers from terpenes and terpenoids

“…To try to combat the issues commonly associated with cationic polymerisation, Yu et al 48 synthesised a Schiff-base nickel catalyst (23) (Figure 4). Single-site late transition metal-based catalysts are more tolerant of functional monomers and are less oxophilic.…”