Polymers of Higher Olefins

Abstract

The article describes polymeric materials derived from the higher α‐olefins with carbon atom numbers of four or higher as well as polymers of cycloolefins. Crystalline polymers of higher α‐olefins belong to two classes of stereoregular polymers, isotactic and syndiotactic. Isotactic polymers are produced with two types of catalysts, heterogeneous Ziegler‐Natta catalysts and bridged metallocene catalysts. Other metallocene catalysts produce either crystalline syndiotactic polymers or amorphous atactic polymers. Higher α‐olefins can also be polymerized with cationic initiators to amorphous oligomeric materials. Cycloolefins are polymerized by two different mechanisms: the ring‐opening metathesis reaction catalyzed by tungsten or molybdenum compounds, and polymerization reactions without ring opening catalyzed by metallocenes. Two isotactic polymers of higher α‐olefins, poly(1‐butene) and poly(4‐methyl‐1‐pentene), as well as oligomers of linear α‐olefins and polymers of certain cycloolefins (polydicyclopentadiene, polyoctenamers, and norbornene elastomers) are produced commercially. Crystalline poly(1‐butene) is used to manufacture pipe, tubing, and blown film. Crystalline poly(4‐methyl‐1‐pentene) is a highly transparent plastic used for the manufacture of medical and chemical laboratory equipment as well as a variety of injection‐molded articles. Liquid oligomers of higher linear α‐olefins produced with cationic initiators have found wide applications as base oils in the formulation of various industrial lubricants; among other applications, they are used in synthetic lubricating oils for cars, transformer oils, and transmission and crankcase fluids. Polymers of cyclooctene are mostly used as components in rubber and compositions based on PVC or polystyrene. Cured liquid‐molding resins based on polydicyclopentadiene are used for the manufacture of automotive parts for trucks, snowmobiles, wheel loaders, and recreational vehicles.

Selective Ethylene Oligomerization with Chromium-Based Metal–Organic Framework MIL-100 Evacuated under Different Temperatures

“…Ethylene oligomerization has been dominated for ages by nonselective ones which yield a wide spectrum of linear α-olefins often following a Schulz–Flory distribution or a Poisson distribution . The light fraction of linear α-olefins (LAOs), particularly C4, C6, and C8, are employed as comonomers for the production of linear low-density polyethylene (LLDPE) copolymers . Continually increasing demand for these short-chain oligomers has led to great interest in selective ethylene oligomerization technologies .…”