Poly butene

RAFF, R. A. V. and DOAK, K. w. (Eds.), Crystalline Olefin Polymers, Interscience, New York (1964) RUBIN, I. D., Poly-1-butene its Preparation and Properties, Macdonald, London (1969)... 

Mobil-Witco-shell A process for making poly (1-butene) by polymerizing 1-butene with a Ziegler catalyst in an excess of liquid monomer. 

Figure 2.12 Maps of conformational energy of various syndiotactic polymers as function of backbone torsion angles 0 and 0227 (a) syndiotactic polystyrene, (b) polypropylene, (c) poly (1-butene), and (d) poly(4-methyl-l-pentene). Succession of torsion angles. .. 0i 0i 0202 - - -[s(M/N)2 symmetry] has been assumed. Isoenergetic curves are reported every 5 kJ/mol of monomeric units with respect to absolute minimum of each map assumed as zero. Values of energies corresponding to minima (x) are also indicated. Experimental conformations observed for different polymorphic forms of polymers are indicated by triangles. (Reproduced with permission from Ref. 27. Copyright 1992 by the Socicta Chimica Italiana.)...

Poly(l,4-benzamide) (PBA), 13 371 Poly(1-butene) (PB), 4 429. See also Blown PB film Isotactic PB resins Isotactic poly(l- butene) (PB) PB entries Pipe-grade PB resin Syndiotactic poly(1-butene) (PB) mechanical properties of, 20 418 polymerization processes for, 20 424-425 uses of, 20 430-431 commercial manufacture of, 20 429 Poly-1-olefins, regioregular, 26 513 Poly(l,4-butylene terephthalate) (PBT), 10 188... 

Liu and Zhong introduced a number of QSPR models based on molecular connectivity indices [151, 152], In a first iteration, the researchers developed polymer-dependent correlations descriptors were calculated for a set of solvents and models were developed per polymer type [151], Polymer classes under consideration were polystyrene, polyethylene, poly-1-butene, poly-l-pentene, poly(4-methyl-l-pentene), polydimethylsiloxane, and polyisobutylene. As the authors fail to provide any validation for their models, it is difficult to asses their predictive power. In a subsequent iteration and general expansion of this study, mixed and therefore more general models based on the calculated connectivity indices of both solvent and polymers were developed. While it is unclear from the paper which polymer representation was used for the calculation of the connectivity indices, the best regression model (eight parameter model) yields only acceptable predictive power (R = 0.77, = 0.77, s = 34.47 for the training set, R = 0.75... 

With a few exceptions, 1,2-disubstituted alkenes are not polymerized because of steric hindrance. The exceptions include 1-deuteropropene (Sec. 8-4g) and cydoalkenes. Polymers are obtained from some 1,2-disubstituted alkenes, but the reactions involve isomerization of the monomer to a 1-alkene prior to polymerization, e.g., 2-butene yields poly( 1-butene) [Endo et al., 1979]. There is one report of polymerization of trans-2-butene to poly( ranv-2-butene) using the a-diimine nickel initiators described in Sec. 8-8b [Leatherman and Brookhart,... 

The principal polyolefins are low-density polyethylene (ldpe), high-density polyethylene (hope), linear low-density polyethylene (lldpe), polypropylene (PP), polyisobutylene (PIB), poly-1-butene (PB), copolymers of ethylene and propylene (EP), and proprietary copolymers of ethylene and alpha olefins. Since all these polymers are aliphatic hydrocarbons, the amorphous polymers are soluble in aliphatic hydrocarbon solvents with similar solubility parameters. Like other alkanes, they are resistant to attack by most ionic and most polar chemicals their usual reactions are limited to combustion, chemical oxidation, chlorination, nitration, and free-radical reactions. 

The preparation of poly (1-butene) containing isotactic pentads using procatalyst... 

Poly(1-butene). Loy (31) reported that the spectrum of high energy-irradiated poly(1-butene) at — 190°C. gave a poorly resolved six-line spectrum, with a hyperfine splitting constant of 21 gauss, indicating that the radicals formed have the structure (XVI) ... 

In more extensive studies carried out by Hukuda, Kusumoto, Ka-wano, and Takayanagi (17, 26, 43) three different samples of isotactic poly (1-butene) were used one amorphous, one of low crystallinity... 

Only one ESR study on the radicals formed by ultraviolet light in poly (1-butene) has been reported (4, 5). In this work ethyl radicals giving a sextet spectrum with a hyperfine splitting constant of 27 gauss... 

XX) were observed for the first time from poly (1-butene). 

On warming to — 30°C., the spectrum of the crystalline samples changed to a sextet with a doublet substructure. By analogy with poly( 1-butene) this spectrum was interpreted as arising from allylic radicals (XXII), but this assignment needs further justification. 

The G values for S02 and butene production from the irradiation of poly (1-butene sulfone) are shown in Figure 3 as a function of temperature from... 

Figure 3. Temperature dependence of the yields (G values) of S02 and butene from 7 irradiation of poly (1 -butene sulfone).

There is evidence that both ionic and free radical species are involved in the degradation and depolymerization of poly (olefin sulfone) s by high energy radiation (70). Thus, the yields of olefins from poly (1-butene sulfone) at 30 °C (the sample was heated to 70 °C during removal of the gaseous products) are shown in Table II. The butene is not solely 1-butene, but comprises significant proportions of all three isomers, 1-butene, 2-butene and isobutene. 

Table II. Yields of Butene Isomers from the Radiolysis of Poly (1-Butene Sulfone) at 30 °C...

Huels and Mobil developed technologies473 to manufacture isotactic poly (1-butene), a less important and more expensive polymer by Ziegler-Natta catalysts. The Mobil process474 is carried out in excess 1-butene and produces highly isotactic polymer. The Huels technology475 is a slurry operation and requires removal of the atactic isomer. 

Read, C.S.. R. Wilhalm, and Y. Yoslnda SRI Chemical Economics Handbook Linear Alpha Olefins, SRI International, Menlo Park, CA, Oct. 1993 Rubin, IT). Poly (1-Butene) Its Preparation and Properties, Gordon Breach, New York, 1968. 

It must be concluded from the results that reactions take place which change the number of active sites present, due to the different behavior of the polymers in solution. With polyethylene, crystalline insoluble globules cause break-up of the catalyst aggregates, and even crystal scission with poly( 1-butene) the chains are highly solubilized. 

Pig. 10. Normalized metal-polymer bond concentration (MPB) as function of yield of polyethylene in grams (curve E), polypropylene (curve P), and poly( 1-butene) (curve B). From Schnecko el al (12). 

Epitaxial Crystallization of Isotactic Poly(1-Butene), Form I... 

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