Hexadienes copolymerization

Copolymer composition vs. monomer feed data were then obtained for 1-hexene (M ) and 5-methyl-1,4-hexadiene copolymerizations (Table VI). The data show that the copolymer compositions measured by 300 MHz %-NMR spectroscopy are essentially identical to the monomer feed. The calculated reactivity ratios were 1.1 + 0.2 for each of the two monomers. 

COPOLYMER COMPOSITION vs MONOMER FEED COMPOSITION FOR 1-HEXENE/5-CH3-l,4-HEXADIENE COPOLYMERIZATIONS... 

Ethylene—Propylene Rubber. Ethylene and propjiene copolymerize to produce a wide range of elastomeric and thermoplastic products. Often a third monomer such dicyclopentadiene, hexadiene, or ethylene norbomene is incorporated at 2—12% into the polymer backbone and leads to the designation ethylene—propylene—diene monomer (EPDM) mbber (see Elastomers, synthetic-ethylene-propylene-diene rubber). The third monomer introduces sites of unsaturation that allow vulcanization by conventional sulfur cures. At high levels of third monomer it is possible to achieve cure rates that are equivalent to conventional mbbers such as SBR and PBD. Ethylene—propylene mbber (EPR) requires peroxide vulcanization. 

Some mechanisms of radical-initiated migration copolymerization of di-alkyl(diphenyl)stannanes with non-conjugated epoxyalkadienes such as 4,4-epoxy-l,7-heptadiene (I) and 3-glycidyl-oxy-l,6-hexadiene (II) have been discussed 98). 

Copolymerization. The reactivity ratios of 1-hexene (M ) with 5-methyl-l,4-hexadiene (M2) were determined by copolymerization at 30°C in hexane solvent using a Et2AlCl2/6-TiCl3 AA catalyst system (Al/Ti atomic ratio = 1.5). Copolymerizations were conducted in 4-oz. bottles using concentrations of 10 g. monomer in 40 g. hexane and 5.0 mmoles TiCl3 per 100 g. monomer. All other copolymerizations were conducted under similar conditions. The reactivity ratios were calculated by the. Tidwell-Mortimer (22) computer method. The compositions of the copolymers were measured by using 300 MHz H-NMR. 

We showed (7) earlier that copolymers of higher a-olefins, particularly 1-hexene, with 5-methyl-1,4-hexadiene can be sulfur-cured readily and that they contain unsaturation approximating the level of the methylhexadiene charged. In view of this and the excellent durability (8) during flexing exhibited by vulcanizates of such copolymers, we were interested in determining the copolymer structure and the reactivity ratios of 1-hexene and 5-methyl-l,4-hexadiene during copolymerization. 

The reduced reactivity of 5-methy1-1-hexene is consistent with the expected steric effect due to methyl substitution at the 5-carbon position. Apparently, the internal double bond in 5-methyl-l,4-hexadiene assists in its complexation at the active site(s) of the catalyst prior to its polymerization and thereby the "local concentration" of this monomer is higher than the feed concentration during copolymerization with 1-hexene. This view is consistent with the observation that the overall rates of polymerization, under the same conditions, are much lower for the system containing 5-methyl-1,4-hexadiene. 

These requirements have met using a mixed catalystic system consisting of an iron catalyst complex that can oligomerize ethylene and a zirconium transition metal complex that can copolymerize ethylene and the nonconjugated monomer 5-ethylidene-2-norbomene. Using this catalytic pair nonbrancy poly(ethylene-co5-ethylidene-2-norbomene) and poly (ethylene-col,4-hexadiene) were prepared. 

With larger amount of propylene a random copolymer known as ethylene-propylene-monomer (EPM) copolymer is formed, which is a useful elastomer with easy processability and improved optical properties.208,449 Copolymerization of ethylene and propylene with a nonconjugated diene [EPDM or ethylene-propylene-diene-monomer copolymer] introduces unsaturation into the polymer structure, allowing the further improvement of physical properties by crosslinking (sulfur vulcanization) 443,450 Only three dienes are employed commercially in EPDM manufacture dicyclopentadiene, 1,4-hexadiene, and the most extensively used 5-ethylidene-2-norbomene. 

Polycarbophil. Polycarbophil [73038-24-1] (copolymer of acrylic acid and divinyl glycol (l,5-hexadiene-3,4-diol [1069-23-4])) consists of white-to-creamy white granules having a slight ester-like odor. It swells to contain a maximum of 1.5% water, but is insoluble in water and most organic solvents. It is prepared by copolymerization of acrylic acid and divinyl glycerol in a hot salt slurry using azobisisobutyronitrile as the initiator. 

The effect of nucleophilic dienes on the copolymerization of ethylene and propylene has been reported by Gladding, Fisher and Collette (88). Table 8 shows that 1.4-hexadiene decreased the tendency for propylene to enter into the ethylene-propylene terpolymer, produced by a triisobutyl aluminum-vanadium oxychloride catalyst. 

Cope rearrangement (Continued) 1,5-hexadiene, 170 interaction diagram, 171 orbital analysis, 170-171 oxy-Cope, 170 Copolymerization CO + alkenes, 293-296 interaction diagram, 295 Core Hamiltonian, 35 Correlation diagrams... 

The proposed idea that metal alkyhdene complexes are be able to catalyze olefin metathesis was confirmed in 1980 [8] and consolidated in 1986 by Schrock with the development of the first well-characterized, highly active, neutral tungsten (Cl, Fig. 3) [9] and molybdenum (C2) [10] alkylidene complexes. These complexes were able to catalyze both the metathesis of different olefins and the ROMP of functionalized norbomene to polynorbomene with low polydispersities [11]. Moreover, these catalysts were used by Wagener and coworkers to perform the first quantitative ADMET polymerization [12] and copolymerization [13] of 1,5-hexadiene and 1,9-decadiene. However, the low stability of these catalysts in... 

A study on the homo- and copolymerization of a variety of dienes such as 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, E-l,3-pentadiene, E-l,3-hexadiene, E-l,3-heptadiene, E-l,3-octadiene, E,E-2,4-hexadiene, E-2-methyl-l,3-pentadiene, 1,3-cyclohexadiene mainly focused on mechanistic aspects [139]. It was shown that 1,4-disubstituted butadienes yield frans-1,4-polymers, whereas 2,3-disubstituted butadienes mainly resulted in cis- 1,4-polymers. Polymers obtained by the polymerization of 1,3-disubstituted butadienes showed a mixed trans-1,4/cis-1,4 structure (60/40). The microstructures of the investigated polymers are summarized in Table 26. 

Figure 5 Productivity in the copolymerization of ethylene with 1-propene, 1-hexene or 1,5-hexadiene...

The highest productivity of 4400 kg polymer/g Zr resulted in the homopolymerization of ethylene. It was found lower in the copolymerization with propene, 1-hexene and 1,5-hexadiene. With increasing concentration of the comonomer in the feed the productivity decreased and was only 50 to 600 kg polymer/g Zr in the homopolymerization of the pure comonomers. The lowest productivity was observed with 1,5-hexadiene. 

The polymerization tests with ethylene and 1-olefines as well as with dienes showed a good ability of the metallocene catalyst for copolymerization. Interesting results from practical and theoretical point of view could be gained in the copolymerization of ethylene and 1,5-hexadiene. During polymerization first a complexation of one of the double bonds of 1,5-hexadiene takes place at the vacant coordination side of the transition metal. After insertion into the polymer chain the complexation of the second double bond occurs followed by intramolecular cyclisation of the 5-membered ring. Analysis of the 13C-NMR spectra reveals an incorporation of 4.2 mole% 1,5-hexadiene and a predominance of trans rings caused by the diastereoselectivity of the cyclisation step. 

The V(acac)3-mediated hompolymerization of ethylene is not living and the polydisper-sity index is quite high (2.0). Nevertheless, ethylene can be successfully copolymerized with propylene while maintaining the livingness of the process. Moreover, the enolate ligated vanadium is a catalyst for the living polymerization of 1,5-hexadiene and copolymerization with propylene. It must be noted that polymerization of 1,5-hexadiene is a route to a polymer that combines constitutive 1,3-cyclopentylenemethylene units (2 ) and vinyltetramethylene units. Therefore, pendant unsaturations are available for further functionalization. 

Two classes of diene have been copolymerized successfully with ethylene/propene, in both of which one double bond is deactivated such that the monomer behaves as a mono-olefin. These are unconjugated diolefins, such as cis and trans 1,4-hexadiene or 3,7-dimethyl 1,6-octa-diene, and compounds containing the 2-norbornene structure... 

Complex 87 was used for propylene-1-hexene co-polymerization. It has been suggested that blocks of iPP and poly-1-hexene were joined to form a poly(iPP-rti-iPH) block co-polymers.1070 Propylene and 1,5-hexadiene have been copolymerized with the 138/MAO catalyst.1229 The NMR spectroscopy indicated that the propylene homosequences are remarkably syndiotactic. As in the case of hexadiene homopolymerization with the same catalyst (see Figure 55), the hexadiene is incorporated as methylene-1,3-cyclopentane or 3-vinyl-tetramethylene units. Lower propylene concentration favored the formation of methylene-1,3-cyclopentane units, while higher propylene concentration favored 3-vinyl-tetramethylene units. Furthermore, an sEE-block-pcAyOP-co-HE)) diblock co-polymer was synthesized by first polymerizing propylene to sPP for 2h and then adding 1,5-hexadiene for 6 additional h.1229... 

Et(Ind)2ZrCl2/MAO gives copolymers of ethylene or propylene with nonconjugated dienes, such as 2-methyl-1,4-pentadiene, 7-methyl-1,6-octadiene and 1,7-octadiene, (Eq. 23) [103]. rac-Et(Ind)2ZrCl2/MAO also catalyzes copolymerizations of asymmetrically substituted linear dienes, 6-phenyl-1,5-hexadiene, 7-methyl-1,6-octadiene, and R-(+)-5,7-dimethyl- 1,6-octadiene. The copolymerization of R-(+)-5,7-dimethyl-l,6-octadiene with propylene to give the polymer with ca. 15% diene incorporation. The ratio of the diene-derived part is ca. 15% of the polymer [104]. 

Propylene-fr-poly(methylene-l,3-cyclopentane-co-propylene) was synthesized by the copolymerization of propylene with 1,5-hexadiene by MgCl2-supported Ziegler-Natta catalyst using a stopped-flow technique [118]. 

Abu-Surrah reported the copolymerization of several a, ca-dienes with CO catalyzed by [Pd(dppp)(NCMe)2](BF4)2 [170]. Although copolymerization of 1,5-hexadiene with CO proceeds via complete cyclization of diene monomer, the copolymerization of 1,7-octadiene and l,6-heptadien-4-ol gives copolymers without a ring structure and with pendant vinyl groups. 

In addition to propylene, other nonconjugated olefins have been copolymerized with CO using enantiopure palladium catalysts. Allylbenzene, 1-butene, 1-heptene, 4-methyl-l-pentene, and cis-2-butene [84,85] as well as hydroxy- and carboxylic acid-functionalized monomers [87] have been polymerized to give optically active polymers. Waymouth, Takaya and Nozaki have recently reported the enantioselective cyclocopolymerization of 1,5-hexadiene and CO [88,89]. 

Novel iron carbonyl monomer, r)4-(2,4-hexadien-l-yl acrylate)tricarbonyl-iron, 23, was prepared and both homopolymerized and copolymerized with acrylonitrile, vinyl acetate, styrene, and methyl methacrylate using AIBN initiation in benzene.70,71 72 The reactivity ratios obtained demonstrated that 23 was a more active acrylate than ferrocenylmethyl acrylate, 2. The thermal decomposition of the soluble homopolymer in air at 200°C led to the formation of Fe203 particles within a cross-linked matrix. This monomer raised the glass transition temperatures of the copolymers.70 The T)4-(diene)tricarbonyliron functions of 23 in styrene copolymers were converted in high yields to TT-allyltetracarbonyliron cations in the presence of HBF4 and CO.71 Exposure to nucleophiles gave 1,4-addition products of the diene group.71... 

An important extension of Ziegler-Natta polymerization is the copolymerization of styrene, butadiene and a third component such as dicyclopentadiene or 1, 4-hexadiene to give synthetic rubbers. Vanadyl halides rather than titanium halides are then used as the metal catalyst. 

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