Polyolefins are the most consumed polymeric materials extensively used in our daily life and are usually generated by coordination polymerization in the polyolefin industry. Olefin polymerization catalysts containing transition metal–organic compound combinations are undoubtedly crucial for the development of the polyolefin industry. The nitrogen donor atom has attracted considerable interest and is widely used in combination with the transition metal for the fine-tuning of the chemical environment around the metal center. In addition to widely reported olefin polymerization catalysts with imine and amide donors (sp² hybrid N), late transition metal catalysts with chelating amine donors (sp³ hybrid N) for olefin polymerization have never been reviewed. In this review paper, we focus on late transition metal (Ni, Pd, Fe, and Co) catalysts with chelating amines for olefin polymerization. A variety of late transition metal catalysts bearing different neutral amine donors are surveyed for olefin polymerization, including amine–imine, amine–pyridine, α-diamine, and [N, N, N] tridentate ligands with amine donors. The relationship between catalyst structure and catalytic performance is also encompassed. This review aims to promote the design of late transition metal catalysts with unique chelating amine donors for the development of high-performance polyolefin materials.

The copolymers of carbon monoxide (CO) and ethylene, namely aliphatic polyketones (PKs), have attracted considerable attention due to their unique property and degradation. Based on the arrangement of the ethylene and carbonyl groups in the polymer chain, PKs can be divided into perfect alternating and non-perfect alternating copolymers. Perfect alternating PKs have been previously reviewed, we herein focus on recent advances in the synthesis of PKs without a perfect alternating structure including non-perfect alternating PKs and PE with in-chain ketones. The chain structure of PKs, catalytic copolymerization mechanism, and non-alternating polymerization catalysts including phosphine–sulfonate Pd, diphosphazane monoxide (PNPO) Pd/Ni, and phosphinophenolate Ni catalysts are comprehensively summarized. This review aims to enlighten the design of ethylene/CO non-alternating polymerization catalysts for the development of new polyketone materials.

The homopolymerization of norbornene and the copolymerization of norbornene and ethylene were carried out using the neutral α-sulfonate-β-diimine nickel catalyst SD-Ni. The neutral α-sulfonate-β-diimine catalyst is highly active in the homopolymerization of norbornene, producing vinyl-addition polynorbornene (PNB) with a high molecular weight. The copolymerization of norbornene (NB) and ethylene (E) using the catalyst SD-Ni was also investigated. The α-sulfonate-β-diimine catalyst SD-Ni shows distinctive catalytic copolymerization properties to produce high-molecular-weight E-NB copolymers with low norbornene incorporation. Importantly, microstructure analyses confirm that the resultant E-NB copolymers are branched cyclo-olefin copolymers (COCs) with branched polyethylene units.

Although hypercrosslinked porous polymers as highly efficient adsorbents can remove pollutants, hypercrosslinked polymers (HCPs) themselves are also a source of white plastic pollution. Development of degradable HCPs is highly desirable based on the full environmental protection concept. In this paper, we reported the direct synthesis of hypercrosslinked polyketones (HCPK-X, X = H, O ^t Bu) generated from degradable aromatic polyketones via external crosslinking technique. The hypercrosslinked structure of HCPK-X was fully characterized, and HCPK-O ^t Bu had a mesopores structure (1.27–68.5 nm) and large surface area ( S _BET = 321 m ² /g). HCPK-O ^t Bu exhibits a good adsorption capability for aniline removal from aqueous solution, and its enhanced adsorption capability is ascribed to the interactions between aniline and the carbonyl and tert -butoxy groups. The photodegradation of hypercrosslinked polyketones was evaluated and emphasized. The prepared hypercrosslinked polyketones can rapidly and efficiently decompose under UV light irradiation, which represents the first sample of degradable hypercrosslinked polymers.