Propylene-butene copolymers

Several peaks arising from different pentad and hexad comonomer sequences have been observed n the C-NMR spectrum of stereoregular 1-butene-propylene copolymers. The paper by Aoki and co-workers [54] demonstrated that the analytical method based on the two-dimensional (2D)-INADEQUATE spectrum and the chemical shift calculation via the y-effect is very powerful for the assignment of C-NMR spectra of higher a-olefin copolymers. A stereoregular 1-butene-propylene copolymer is a suitable example because reliable assignments have been proposed by a reaction probability model [55]. 

In the region of the methyl carbon in the propylene unit (21.4 ppm to 22.0 ppm), the side-chain methylene carbon in the 1-butene unit (27.5 ppm to 28.5 ppm), and the central methylene carbon of the PP diad (46.5 ppm to 47.5 ppm), the peaks arising from different comonomers sequences longer than pentad are observed. To provide assignments of these peaks, chemical shift differences among pentad and hexad comonomers sequences were calculated by the y-effect method. Table 5.6 shows the calculated chemical shift differences in the resonance regions of methyl and methylene carbons in 1-butene-propylene copolymer ... 

Planar zig-zag conformation of 1-butene-propylene copolymer methane resonance regions were excluded because of their low spectral resolution. 

Regions of Methyl and Methylene Carbons of a 1-Butene-Propylene Copolymer... 

MAJOR POLYMER APPLICATIONS ABS, acrylics, butene propylene copolymer, cellulose acetate, cellulose acetate butyrate, cyanoacrylate, ethyl cellulose, epoxy resin, polyamide, polyester, polyimide, polymethylmethacrylate, polypropylene, polysulfone, poly(phenylene sulfide), polyvinylbutyral, polyurethane ... 

Figure 7.4 C-NMR spectrum of a stereoregular 1-butene-propylene copolymer. [Reprinted with permission from A. Aoki, T. Hayashi and T. Asakura, Macromolecules, 1992, 25, 1, 155. 1992, ACS [46])...

Figure 7.4 shows the C-NMR spectrum of a stereoregular 1-butene-propylene copolymer. On the basis of previous assigmnents [58], complicated peaks arising from different comonomer sequences longer than pentad are observed in the resonance regions of the methyl carbon of propylene (A), the central methylene carbon of a PP diad (B), and the side-chain methylene carbons of 1-bntene (C) among propylene units. 

Table 7.4 Calculated C-NMR Chemical Shift Differences in the Resonance Regions of Methyl and Methylene Carbons of a 1-Butene-Propylene Copolymer ...

Figure 19 (a) Peak melting temperature as a function of the branch content in ethylene-octene copolymers (labelled -O, and symbol —B (symbol, ) and -P (symbol, A) are for ethylene-butene and ethylene-propylene copolymers, respectively) and obtained from homogeneous metallocene catalysts show a linear profile, (b) Ziegler-Natta ethylene-octene copolymers do not show a linear relationship between peak melting point and branch content [125]. Reproduced from Kim and Phillips [125]. Reprinted with permission of John Wiley Sons, Inc. 

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. 

Two examples of propylene copolymers pyrolysis are given below. The first example is for poly(propyiene-co-l-butene) 14 % wt. butene, CAS 29160-13-2. The pyrogram is shown in Figure 6.1.22. The pyrolysis was done at 600° C in He with separation on a Carbowax column and MS detection, similarly to other polymers previously discussed in this book (see also Table 4.2.2). 

Polymer (B) Characterization Solvent (A) ethylene/propylene copolymer M /kg.mor = 0.78,M ,/kg.mor = 0.79, 50 mol% propene, alternating ethylene/propylene units from complete hydrogenation of polyisoprene 1-butene C4H8 1992CH1 106-98-9... 

Ethylene-propylene copolymers can be made with narrower polydispersity index and chemical composition distribution than those from conventional Ziegler-Natta catalysts. Similiarly, LLDPE s prepared with Cp ZrClj/MAO catalyst have lower melt temperatures, for the same level of incorporation of 1 -butene, than copolymers made from a heterogenous TiCl - triethylaluminum system. This indicates that the metallocene derived LLDPE has a more uniform distribution of 1 -butene in the copolymer, i.e., it has a narrower chemical composition distribution. 

Polypropylene, PP, or poly (pentene-co-propylene) was reactor blended with ethylene-butene or ethylene-pentene copolymer. The product was melt blended with PP to give material with improved performance. In the second patent, ethylene-propylene copolymer, EPR, was blended with PP. The alloys showed good mechanical properties. In the Sumitomo patent, to improve impact strength, PP was blended with 5-30 wt% of either polyhexene or polyoctene... 

An in-reactor TPO may be defined as a reactor-produced polypropylene copolymer (PP-b-E/P), containing between 22 % and 55 % ethylene-propylene copolymer blocks. Small amounts of other comonomers, such as octene-1 or butene-1, may also be present so as to provide unique functionality. In-reactor propylene block copolymers containing less than 20 % ethylene are fairly hard and are usually classified as impact polypropylenes. Reactor-made polymers containing >50 % ethylene are soft and also have relatively poor elastomeric properties - these are classified as plastomers. 

From Z. Bartczak, V. Chiono, M. Pracella, Blends of propylene-ethylene and propylene-1-butene random copolymers I. Morphology and structure. Polymer 45 (22) (2004) 7549-7561. 

Olefin Copolymers Molded EEA (ethylene ethyl acrylate) EVA (ethylene vinyl acetate) Ethylene butene Propylene—ethylene ionomer D35 (Shore) D36 (Shore) D65 (Shore) D60 (Shore)... 

Ethylene may be copolymerized with numerous monomers but only a few such copolymers have achieved commercial status. The more important comonomers are propylene, 1-butene, vinyl acetate, ethyl acrylate and carboxylic acids. Ethylene-propylene copolymers are particularly important and are discussed in Sections 2.7 and 2.8. 

Homo- and copolymerlzation of ethylene are receiving considerable attention In the present decade, due to different reasons polyethylene Is the world s most used polymer low linear density polyethylene (LLDPE) produced by copolymerization of ethylene with high a-olefins, such as 1-butene, 1-hexene, 1-octene, etc.. Is one of the most rapidly growing polymers possibilities of producing different types of ethylene-propylene copolymers, such as random and block copolymers, etc. 

A pyrolysis - gas chromatography method has been described [44-46] for the determination of the composition of an ethylene-butene-1 copolymer containing up to about 10% butene. Pyrolyses were carried out at 410 °C in an evacuated gas vial and the products swept into the gas chromatograph. Under these pyrolysis conditions, it is possible to analyse the pyrolysis gas components and obtain data within a range of about 10% relative standard deviation. The peaks observed on the chromatogram were methane, ethylene, ethane, combined propylene and propane, isobutane, 1-butene, trans-2-butene, ds-2-butene, 2-methyl-butane and w-pentane. 

Aoki and co-workers [55] and others [56-58] used C-NMR spectroscopy to study the microstructure of propylene-butene-1 copolymers. 

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