Polymerization of butenes

Polybutenes. Polybutenes are produced by controlled polymerization of butenes and isobutene (isobutylene) (see Butylenes). A typical polyisobutylene stmcture is... 

Ionic liquid-catalyzed polymerization of butene is not limited to the use of pure alkene feedstocks, which can be relatively expensive. More usefully, the technology can be applied to mixtures of butenes, such as the low-value hydrocarbon feedstocks raffinate I and raffinate II. The raffinate feedstocks are principally C4 hydrocarbon mixtures rich in butenes. When these feedstocks are polymerized in the presence of acidic chloroaluminate(III) ionic liquids, polymeric/oligomeric products with... 

Polybutylene A polymer prepared by the polymerization of butene as the sole monomer. 

This method has been used [147, 148] for determinatiOTi of values for polymerization of butene-1 on a ZN catalyst based on TiCls and VCI3. The value greatly increases at transition from TiCls to VCI3. The same method has also been used [149, 150] for study of propylene polymerization on the catalyst a-TiCl3 + AlEt3, and also for study of ethylene polymerization on the catalyst Y-TiCl3 + AlEt3Cl [151, 152]. However, in the latter cases the cmidition of polymerization stability was not met. It is necessary to notice also that in works [147-152], values were calculated from polymer viscosity data in the assumption that polydispersity of the polymer does not depend on polymerization time. These assumptions are not always met and therefore reduces the reliability of results obtained by this method. 

Polybutene, A microcrystalline thermoplastic produced by polymerization of butene-1. Applications pipes and containers. 

Polyd-butene) Produced commercially in isotactic for by Ziegler-Natta polymerization of butene-1. 

Isotactic poly(l-butene) crystallizes from the melt into an unstable modification which is slowly converted into a thermodynamically more stable form. The two modifications differ in helical structure and density therefore, the product undergoes deformation in the course of time [515,516]. For the polymerization of butene the same catalysts are used as for propene. 

Polymerization of butenes with 72% sulfuric acid 175 M 14pha... 

The polymer we are concerned with is PB-1. In the past this polymer has been referred to as polybutylene, PB, PB-1, and polybutene, as well as its chemically correct name, PB-1. PB-1 is obtained by polymerization of butene-1 with a stereo-specific Z-N catalyst to create a linear, high molecular, isotactic, semicrystalline polymer. PB-1 combines the typical properties of conventional polyolefins with some characteristics of technical polymers. In chemical structure PB-ldiffers from polyethylene and polypropylene only by the number of carbon atoms in Ae monomer molecule, as in Fig. 2.22. 

PB base polymers are semicrystalUne isotactic thermoplastic polyolefins. They are derived from the polymerization of butene-1 monomer with or without other alpha-olefin monomers utilizing a Ziegler-Natta type of catalyst. Their unique crystallization behavior means longer open times of adhesive and sealant formulations compared to other commonly used polymers such as polyethylene and ethylene-vinyl acetate copolymer (EVA). Polybutylene (PB), also called polybutene-1 or poly-1-butene, is different from polybutene or polyisobutylene (PIB). PIB is amorphous and rubbery, and comes in the form of a viscous liquid or big, hard block (6 in. in length and width or could be larger). PB base polymers are sup-pUed in the form of small pellets (about 0.25 in. in diameter) or nibs. 

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