Ethylene and propene were homopolymerized with 11 different metallocene-methylaluminoxane (MAO) catalysts 1-11 using a constant set of parameters. The catalytic activity of the two unbridged and 9 ansa-metallocenes as well as the properties of the polymers, such as molecular weight, width of molecular weight distribution, melting point, and, with polypropene, chain microstructure, were investigated. It was found that structure variations of the catalysts cause rather different catalytic behaviour, which further diversifies the performances with the two different monomers. In some cases this comparison allows insight into the nature of the influencing factors. 0 1992, Huthig & Wepf Verlag, Basel CCC 0025-1 16)3/92/$05,00 Standardized polymerizations of ethylene and propene with . . . Scheme 1: 6 : M t z Z r 7 : Mt=Hf 9 4-R=CH, (2 isomers) 5: R-H

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Sly1 en01 etlici (4.5 nirnol) was dissolved in henzene (8 mL) in a quartz tuhe. The irted (300 nm: light source: Rayonet R P R 3000) and a solution of [I iiig. 1.5 mmol. 152 ILL) in henzene ( 2 mL) was slo\rly added to the rc:iction mixtiirc hy ii syringe (within cii. 2 h). As soon as the aldehyde was fully con'iiiined (TLCJ llie irsxli~ition was slopped and the solvent ecaporated i n v~icuo. The dinstcrconicric tiitlo was detemiincd hy GLC' m d ' H N M R iinnlyses. Escccs s l y 1 e n d ethcr and the desired oxetanc were obtained by coluinn chromatography (ilasli c1iroinatogr;ipliy: eluent. cyc1ohexane;ethyl acetate as ii gradient 200:l + 95, 5 ) . boi-oset;ine\ m -2d.riic~3d and ru(.-2f;ru~3f ii complcte separation of diii-\tcrcoi~umci-\ uiis posiblc. In the other eximples only ;in enrichment of the major diwtercoiwmera could he ~h i e v e d .

The article contains sections titled: 1. Introduction 1.1. Market and Areas of Application 1.2. Nomenclature and Classification 1.3. Properties 1.4. Production 1.5. Producers 2. Market, Producers, and Capacities 2.1. Market 2.2. Producers, Capacities and Capacity Utilization 3. Market Requirements and Impact on Development of Synthetic Rubber 4. Production Processes 5. Ecological and Health Aspects 5.1. Introduction 5.2. Health Aspects 5.2.1. Raw Materials 5.2.2. Processing 5.2.3. Use 5.3. Environment 5.4. Outlook