Propylene ethylene

A good example of a polymer in which sequences of different monomer units occur is ethylene-propylene, and this will be discussed here in some detail. Processes for the manufacture of this polymer can produce several types of polymer which, although they may contain similar proportions of the two monomer units, differ appreciably in their physical properties. The differences in these properties lie not only in the ratio of the two monomers present but also, and very importantly, in the detailed microstructure of the two monomer units in the polymer molecule. Ethylene-propylene copolymers might consist of mixtures of the following types of polymer  

Various methods are available for determining the percentage of ethylene and propylene, the ethylenerpropylene ratio and the type of ethylene and propylene unit sequencing in these polymers, and these methods are discussed in further detail in this section. 

In fact the problem is somewhat more subtle than expressed previously, the types of measurements that are commonly required are  

Several possible techniques are available for carrying out these analyses, and these are now discussed  

Pyrolysis-gas chromatography (Py-GC) can be used to obtain fine detail regarding minor, but often very important detail, concerning polymer structure such as monomer sequences and, also, branching, crosslinking copolymer structure and the nature of the end-groups, and can also be used to elucidate polymer structure between adjacent monomer units in copolymers and to determine monomer ratios in copolymers. 

Tosi and Simonazzi [1] have described an infrared method for the evaluation of the propylene content of ethylene-rich, ethylene-propylene copolymers. This is based on the ratio between the absorbance of the 7.25 pm band and the product of the absorbances by the half width of the 6.85 pm band obtained on diecast polymer film at 160 C (Table 4.1). 

Other infrared methods for the determination of the ethylene - propylene ratio in copolymers are reviewed in Table 4.2. 

Reproduced with permission from G. Tosi and T Simonazzi, Die Angewandte Macromolecular Chemie, 1973, 32, 1, 153 [1]  

25 pm (CCI4 solution) Ratio 13.95/8.7 pm (solid film) 7.25 pm methyl groups Propylene content in range 30-50% propylene High scatter in results Results adversely affected hy polymer crystallinity [3-5] [4-6] 

Ratio 7.25 pm band (solid diecast film) and product of absorbance by the halfwidth of 6.85 pm band Propylene content Calibrated versus C labelled ethylene or propylene copolymers by plotting ratio 7.25/6.55 pm versus % propylene weight fraction [7] 

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There are little or no olefins in crude oil or straight run (direct from crude distillation) products but they are found in refining products, particularly in the fractions coming from conversion of heavy fractions whether or not these processes are thermal or catalytic. The first few compounds of this family are very important raw materials for the petrochemical Industry e.g., ethylene, propylene, and butenes. 

Cryogenic recovery before oligomerization Ethylene Propylene 95% 100%... 

Properly speaking, steam cracking is not a refining process. A key petrochemical process, it has the purpose of producing ethylene, propylene, butadiene, butenes and aromatics (BTX) mainly from light fractions of crude oil (LPG, naphthas), but also from heavy fractions hydrotreated or not (paraffinic vacuum distillates, residue from hydrocracking HOC). 

This form of limited-conversion hydrocracking is a process that selectively prepares high quality residues for the special manufacture of base oils of high viscosity index or treating residues having low BMCl for the conversion of heavy fractions to ethylene, propylene, butadiene and aromatics. 

Several studies have demonstrated the successful incoriDoration of [60]fullerene into polymeric stmctures by following two general concepts (i) in-chain addition, so called pearl necklace type polymers or (ii) on-chain addition pendant polymers. Pendant copolymers emerge predominantly from the controlled mono- and multiple functionalization of the fullerene core with different amine-, azide-, ethylene propylene terjDolymer, polystyrene, poly(oxyethylene) and poly(oxypropylene) precursors [63,64,65,66,62 and 66]. On the other hand, (-CggPd-) polymers of the pearl necklace type were fonned via the periodic linkage of [60]fullerene and Pd monomer units after their initial reaction with thep-xy y ene diradical [69,70 and 71]. 

Furthermore, treatment of the aminopalladation product with bromine affords aziridines[176]. The aziridine 160 was obtained stereoselectively from methylamine and 1-decene in 43% yield. The aminopalladation of PdCl2 complexes of ethylene, propylene, and 1-butene with diethylamine affords the unstable ir-alkylpalladium complex 161, which is converted into the stable chelated acylpalladium complex 162 by treatment with CO[177],... 

Fluorinated Ethylene-Propylene Resin. Polymer molecules of fiuorinated ethylene-propylene consist of predominantly linear chains with this structure ... 

It resembles polytetrafiuoroethylene and fiuorinated ethylene propylene in its chemical resistance, electrical properties, and coefficient of friction. Its strength, hardness, and wear resistance are about equal to the former plastic and superior to that of the latter at temperatures above 150°C. 

Polyolefins. In these thermoplastic elastomers the hard component is a crystalline polyolefin, such as polyethylene or polypropylene, and the soft portion is composed of ethylene-propylene rubber. Attractive forces between the rubber and resin phases serve as labile cross-links. Some contain a chemically cross-linked rubber phase that imparts a higher degree of elasticity. 

Fluorinated ethylene-propylene resin Poly(vinylidene fluoride) Ethylene-tetrafluoroethylene copolymer Ethylene- chlorotrifluoro- ethylene copolymer Cellulose- filled Glass-fiber- reinforced... 

Ethylene-propylene-diene rubber is polymerized from 60 parts ethylene, 40 parts propylene, and a small amount of nonconjugated diene. The nonconjugated diene permits sulfur vulcanization of the polymer instead of using peroxide. 

The weight percent propylene in ethylene-propylene copolymers for different Ziegler-Natta catalysts was measuredt for the initial polymer produced from identical feedstocks. The following results were obtained ... 

EPDM in pLASTOTffiRS, SYNTHETIC - ETHYLENE-PROPYLENE-DIENE RUBBER] (Vol 8) -polycarbonate in [POLYCARBONATES] (Vol 19)... 

FLUORINECOBTPOUNDS,ORGANIC - PERFLUORINATED ETHYLENE-PROPYLENE COPOLYBffiRS] pol 11) Chloropentakis(ethanol) cobalt (II) [32354-52-2]... 

ELASTOTffiRS,SYNTHETIC - ETHYLENE-PROPYLENE-DIENE RUBBER] (Vol 8)... 

FEP in pLUORINE COMPOUNDS, ORGANIC - PERFLUORINATED ETHYLENE-PROPYLENE COPOLYTffiRS] (Vol 11) -of plastic foams pOAMED PLASTICS] (Vol 11)... 

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