Chain growth process, manufacture

Manufacture of Higher Straight-Chain Alcohols by the Ethylene Chain Growth Process... 

A.luminum Jilkyl Chain Growth. Ethyl, Chevron, and Mitsubishi Chemical manufacture higher, linear alpha olefins from ethylene via chain growth on triethyl aluminum (15). The linear products are then used as oxo feedstock for both plasticizer and detergent range alcohols and because the feedstocks are linear, the linearity of the alcohol product, which has an entirely odd number of carbons, is a function of the oxo process employed. Alcohols are manufactured from this type of olefin by Sterling, Exxon, ICI, BASE, Oxochemie, and Mitsubishi Chemical. 

Chain gro tvth polymerization begins when a reactive species and a monomer react to form an active site. There are four principal mechanisms of chain growth polymerization free radical, anionic, cationic, and coordination polymerization. The names of the first three refer to the chemical nature of the active group at the growing end of the monomer. The last type, coordination polymerization, encompasses reactions in which polymers are manufactured in the presence of a catalyst. Coordination polymerization may occur via a free radical, anionic, or cationic reaction. The catalyst acts to increase the speed of the reaction and to provide improved control of the process. 

Plasticizer manufacturers have long recognized the desirable features of straight chain alcohols as plasticizer raw materials, but until recently, they depended entirely on limited production from natural sources for these products. Presently, mixtures of straight chain alcohols of even carbon number are available at commercially attractive prices from the ethylene growth process (2), but the pure alcohols are still too expensive generally to interest the plasticizer manufacture. 

Terephthalic acid (TA) (diacid) is now the major monomer used in the production of PET. It is produced on a world-wide scale and is available in a number of purities. These can be generally referred to as PTA (pure TA), MTA (medium purity TA) or CTA (cmde TA). These descriptions are subjective and used in different ways by manufacturers. The purity of TA is the self-limiting process in PET manufacture. The major impurity in any TA grade is 4-carboxybenzaldehyde and it is a chain growth inhibitor. As the level of impurity increases less reaction can take place. From a food contact point of view the purity or impurities in the TA is important. Both US and EU law state that monomers should be of good technical quality but do not define what that technical quality should be. If no other information is available the... 

Washecfaeck, P. H, Manufacture of higher straight-chain alcohols by the ethylene dim> growth process", ACS 179th jtforioaaf Meeting, Houston, Texas (25/26 March 1980). 

Controlled Radical Polymerization (CRP) is the most recently developed polymerization technology for the preparation of well defined functional materials. Three recently developed CRP processes are based upon forming a dynamic equilibrium between active and dormant species that provides a slower more controlled chain growth than conventional radical polymerization. Nitroxide Mediated Polymerization (NMP), Atom Transfer Radical Polymerization (ATRP) and Reversible Addition Fragmentation Transfer (RAFT) have been developed, and improved, over the past two decades, to provide control over radical polymerization processes. This chapter discusses the patents issued on ATRP initiation procedures, new functional materials prepared by CRP, and discusses recent improvements in all three CRP processes. However the ultimate measure of success for any CRP system is the preparation of conunercially viable products using acceptable economical manufacturing procedures. 

Expansion of plastics into new and replacement markets promises a high rate of growth. Twenty five years ago suitable applications had to be found for the synthetic polymers manufactured at that time. Today s inventors visualize the need for certain materials. They prepare these materials and develop a feasible manufacturing process since macromolecules can be designed for a specific end use. Synthetic polymers can be made with flexible or stiff chains and tailored in length. 

With the growth of Internet-based businesses that are almost virtual in nature (i.e., no manufacturing or fulfillment assets), the process is carried out by contracted specialists. This implies that information integration becomes the key interaction between the supply chain entities. 

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