Vinyl chloride commercial aspects

The use of a commercially available software package (QUANT) is described in the analysis of copolymer films by computer assisted infrared spectroscopy. Important features of the software are illustrated by the example of analysis of vinyl acetate/vinyl chloride copolymers. Critical aspects of method development are explained and error sources are examined. Calibration is reported with a correlation coefficient of 0.9998. 

Poly(vinyl chloride) (PVC) is by volume the second largest thermoplastic manufactured in the world [35]. The world PVC demand in 2003 was about 28 million tonnes and the predicted annual growth rate of world PVC demand is close to 4% [36]. The sustainable expansion of the PVC industry is due to the high versatility of PVC as a plastic raw material together with its low price. A review of the qualitative and quantitative aspects of PVC polymerization can be found in Smallwood [35], Burgess [37], Langsam [38], TorneU and Uustalu [39],Xie etal. [40,41] and Yuan etaZ. [42]. Four polymerization processes (i.e., suspension, bulk, emulsion and solution) are commercially employed in PVC manufacturing. 

The authors analyze conditions of typical syntheses, limitations of their applicability, and possibility of vinyl chloride or dichloroethane application instead of acetylene. They examine chemical engineering aspects of the first synthesis of tetrahydroindole and indole from commercially available oxime of cyclohexanone and acetylene. In addition, the book discusses new facets of pyrroles and N-vinyl pyrroles reactivity in the reactions with the participation of both the pyrrole ring and N-vinyl groups. 

Anionic polymerization of vinyl monomers can be effected with a variety of organometaUic compounds alkyllithium compounds are the most useful class (1,33—35). A variety of simple alkyllithium compounds are available commercially. Most simple alkyllithium compounds are soluble in hydrocarbon solvents such as hexane and cyclohexane and they can be prepared by reaction of the corresponding alkyl chlorides with lithium metal. Methyllithium [917-54-4] and phenyllithium [591-51-5] are available in diethyl ether and cyclohexane—ether solutions, respectively, because they are not soluble in hydrocarbon solvents vinyllithium [917-57-7] and allyllithium [3052-45-7] are also insoluble in hydrocarbon solutions and can only be prepared in ether solutions (38,39). Hydrocarbon-soluble alkyllithium initiators are used directiy to initiate polymerization of styrene and diene monomers quantitatively one unique aspect of hthium-based initiators in hydrocarbon solution is that elastomeric polydienes with high 1,4-microstmcture are obtained (1,24,33—37). Certain alkyllithium compounds can be purified by recrystallization (ethyllithium), sublimation (ethyllithium, /-butyUithium [594-19-4] isopropyllithium [2417-93-8] or distillation (j -butyUithium) (40,41). Unfortunately, / -butyUithium is noncrystaUine and too high boiling to be purified by distiUation (38). Since methyllithium and phenyllithium are crystalline soUds which are insoluble in hydrocarbon solution, they can be precipitated into these solutions and then redissolved in appropriate polar solvents (42,43). OrganometaUic compounds of other alkaU metals are insoluble in hydrocarbon solution and possess negligible vapor pressures as expected for salt-like compounds. 

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