Ethylene-1-butene

A Py-GC method has been described [37-39] for the determination of the composition or an ethylene-butene-1 copolymer containing up to about 10% butane. 

The relationship between the amount of ethylene produced on pyrolysis and the amount of butane in the ethylene-butene copolymer was determined by an IR analysis for ethyl branches. The y intercept of 16.3% ethylene should represent that amount of ethane which would result from a purely linear polyethylene. An essentially unbranched Phillips-type polyethylene polymer yielded 14.5% ethylene, which is fairly close to the predicted 16.3%. 

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Chain Structure. LLDPE resins are copolymers of ethylene and a-olefins with low a-olefin contents. Molecular chains of LLDPE contain units derived both from ethylene, —CH2—CH2—, and from the a-olefin, —CH2—CHR—, where R is C2H for ethylene—1-butene copolymers, for... 

Content of Ot-Olefin. An increase in the a-olefin content of a copolymer results in a decrease of both crystallinity and density, accompanied by a significant reduction of the polymer mechanical modulus (stiffness). Eor example, the modulus values of ethylene—1-butene copolymers with a nonuniform compositional distribution decrease as shown in Table 2 (6). A similar dependence exists for ethylene—1-octene copolymers with uniform branching distribution (7), even though all such materials are, in general, much more elastic (see Table 2). An increase in the a-olefin content in the copolymers also results in a decrease of their tensile strength but a small increase in the elongation at break (8). These two dependencies, however, are not as pronounced as that for the resin modulus. 

Branchings Uniformity. Comparison of uniformly and nonuniformly branched ethylene—1-butene copolymers of the same density (Table 4) shows that uniformly branched resins are much more elastic, their tensile modulus is lower, and their strain recovery is neady complete. 

Blending with LLDPE is used to upgrade the properties and improve the processing of conventional LDPE. For example, by adding 25% of ethylene—1-butene LLDPE resin with I2 of 0.5 to conventional LDPE resin, the dart impact strength of 75 p.m film is increased from 490 to 560 g, the puncture strength from 41 to 49 J /mm (770-920 ft-lbf/in.), and the tear strength from 43 to 63 N /mm (246—360 ppi). CompositionaHy uniform VLDPE resins are used in blends with HDPE, commodity LLDPE, and polypropylene (PP) (70,71,89). 

IFP Process for 1-Butene from Ethylene. 1-Butene is widely used as a comonomer in the production of polyethylene, accounting for over 107,000 t in 1992 and 40% of the total comonomer used. About 60% of the 1-butene produced comes from steam cracking and fluid catalytic cracker effluents (10). This 1-butene is typically produced from by-product raffinate from methyl tert-huty ether production. The recovery of 1-butene from these streams is typically expensive and requires the use of large plants to be economical. Institut Francais du Petrole (IFP) has developed and patented the Alphabutol process which produces 1-butene by selectively dimerizing ethylene. 

Oligomerization of Ethylene. 1-Butene is a small by-product in the production of linear alpha-olefins by oligomerisation of ethylene. Linear alpha-olefins have one double bond at the terminal position and comprise the homologous series of compounds with carbon atoms between 4 and 19. The primary use of alpha-olefins is in the detergent industry. About 245,000 t/yr of 1-butene was produced for chemical use in the Gulf Coast of the United States in 1988 (72). 

Figure 4 Plot of degree of crystallinity (XDSC) from DSC against crystallinity (Xp) determined by density measurements. (A), hydrogenated polybutadienes ( ), ethylene 1-butene copolymers ( ), ethylene 1-octene copolymers. Reprinted with permission from Ref. [72]. Copyright 1984 American Chemical Society. 

The ethylene-1-butene block cannot be obtained directly since the two monomers do not undergo anionic copolymerization. 

Ethylene-1-butene copolymers, 20 180 Ethylene-1-olefin copolymerization, 26 525 Ethylene-acrylic elastomers, 10 696-703 commercial forms of, 10 697-698 dynamic mechanical properties of,... 

Ethylene-1-butene (5%) copolymers possess low density, softening point and these are used for making bottles. 

The rate constants at 25° and the Arrhenius parameters for ethylene, 1-butene, isobutene, m-2-butene, and re-butane, obtained by this technique by Elias (37) are given in Table V. In the fifth column are given... 

To control the consecutive trimerization reaction at an economic level, the liquid phase is equilibrated with an ethylene vapor phase at a constant pressure (e. g., 2 MPa at 50 °C) to ensure a constant ethylene/1-butene ratio in the liquid phase. As a consequence there is only one well-mixed reactor. Each of the two... 

E/O co-polymerization reports with bis(cyclopentadienyl) complexes include ethylene/1-butene, ethylene/l-pentene,254 ethylene/4-methyl-l-pentene,516,522,523 ethylene/1-hexene,229,230,254,446,447,478,481,484,509,512-515, 517-519,522,524-530 ethyiene/1.octene(254,504,505,515,522,531-535 ethyiene/i decene,254,520 ethylene/1-dodecene,254,536 ethylene/1-tetradecene,254,532 ethylene/1-hexadecene,511,512,518,525 ethylene/1-octadecene.532,536... 

The most relevant E/O co-polymerization reports with rzmzz-Cp-amido titanium complexes include ethylene/1-butene,537,538 ethylene/l-hexene,539,540 and ethylene/l-octene.91,442,454,456,457,464,506,541 Ethylene/4-methyl-l-pen-tene co-polymerizations have been reported as well.457,542 The thermal and physical properties of the octene co-polymers produced with ansa-G -amido titanium complexes have been studied.543-546 The importance of the activator has been pointed out in many instances.91,108... 

Figure 8 Run Number Versus Density for a Series of Ethylene 1-Butene, Ethylene-l-Hexene and Ethylene-l-Octene Copolymers Possessing Monomer Dispersities of 94-100...

The stereochemical features of the polymerization were satisfactorily accounted for by considering the nonbonded interactions between the monomer molecule undergoing insertion and the ligands on the vanadium atom. Coordination number five for vanadium was chosen to justify the more relevant data concerning the propylene polymerization and ethylene, 1-butene, and cis-2-butene copolymerization. 

A comparative study of MAH and diethyl maleate grafting—initiated by DCP—to styrene-(ethylene-butylene)-styrene triblock copolymer (SEES) and PS blended with a random ethylene-1-butene copolymer has been described elsewhere (66). The weight ratio of PS to PO components in the block copolymer was the same as in the blend (20% PO and 80 wt% PS). The analysis of the functionalized PS/PO blend—after PS had been extracted in a solvent—showed that the monomer was grafted only to the PO component. Considering that the PS/ PO blend and SEES have quite similar phase and molecular structures, it was concluded that in styrene-containing block copolymers only aliphatic blocks become functionalized. 

Open-chain aliphatic hydrocarbons constitute alkanes, alkenes, alkynes, and their isomers. Alkanes have the general formula C H2 +2, where n is the number of carbon atoms in the molecnles, snch as methane, propane, n-pentane, and isooctane. Alkenes or olefins are nnsaturated compounds, characterized by one or more double bonds between the carbon atoms. Their general formula is C H2 . Examples are ethylene, 1-butene, and... 

The tosylation of carbon can be accomplished using electron transfer conditions. Treatment of styrene and analogs with Copper(II) Chloride and tosyl chloride or Benzenesulfonyl Chloride results in a formal replacement of the vinyl proton by the sulfonyl moiety (eq 35). The intermediacy of a trans-(S-chloro sulfone has been demonstrated by H NMR. Treatment with base induced the elimination of HCl. A variety of other sulfonyl transfer reagents can be ertployed in the synthesis of isolated /3-chloro sulfones, with good results (60-97% yield) for a variety of alkenes (ethylene, 1-butene, 2-butene, 1-octene, acrylonitrile, methyl acrylate, and 1,3-butadiene). ... 

CHE Chen, A.-Q. and Radosz, M., Phase equilibria of dilute poly(ethylene-co-l-butene) solutions in ethylene, 1-butene, and 1-butene+ethylene,/. Chem. Eng. Data, 44, 854, 1999. 

Anionic polymerization of butadiene, followed by hydrogenation, provides a route to compositionally homogeneous materials similar in structure to ethylene/1 -butene copolymers. The copolyma- composition can be varied by addition of polar modifiers to the polymerization mixture, thus generating materials with differing mole fractions of 1,2 addition, jCjj. 

MOO Moore, S.J. and Wanke, S.E., Solubility of ethylene, 1-butene and 1-hexene in polyethylenes (experimental data by S.E. Wanke), Chem. Eng. Sci., 56,4121, 2001. 

Ethylene/1-butene copolymer 1-butene and ethene 1999CHE... 

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