Copolymerization butadiene/propylene

The ethylene-propylene (EP), ethylene-butadiene (EB) and propylene-butadiene (PB) copolymerizations and ethylene-propylene-butadiene (EPB) terpolymerization with a supported catalyst, TiCl4/MgCl2/ethyl benzoate-AlEt3, are described. The catalytic activities were enhanced in the EP copolymerizations, while the catalytic activities were decreased in the co- and terpolymerizations containing butadiene as compared with the corresponding homopolymerizations. It was found that the butadiene units in these co- and terpolymers are mostly in trans-1,4 configuration and long blocked sequences. 

Boron Bromide. Approximately 30% of BBr produced in the United States is consumed in the manufacture of proprietory pharmaceuticals (qv) (7). BBr is used in the manufacture of isotopicaHy enriched crystalline boron, as a Etiedel-Crafts catalyst in various polymerization, alkylation, and acylation reactions, and in semiconductor doping and etching. Examples of use of BBr as a catalyst include copolymerization of butadiene with olefins (112) polymerization of ethylene and propylene (113), and A/-vinylcarbazole (114) in hydroboration reactions and in tritium labeling of steroids and aryl rings (5). 

We have considerable latitude when it comes to choosing the chemical composition of rubber toughened polystyrene. Suitable unsaturated rubbers include styrene-butadiene copolymers, cis 1,4 polybutadiene, and ethylene-propylene-diene copolymers. Acrylonitrile-butadiene-styrene is a more complex type of block copolymer. It is made by swelling polybutadiene with styrene and acrylonitrile, then initiating copolymerization. This typically takes place in an emulsion polymerization process. 

Alternating Copolymerization. In the last part of this paper we would like to refer briefly to our findings in connection with the alternating copolymerization of dienes with olefins. The alternating copolymerization of butadiene with propylene was first investigated in 1969 by Furukawa and others (15, 16, 17). They used catalyst systems based on titanium or vanadium compounds. 

In the polymer field, reactions of this type are subject to several limitations related to the structure and symmetry of the resultant polymers. In effect, the stereospecific polymerization of propylene is in itself an enantioface-diflferen-tiating reaction, but the polymer lacks chirality. As already seen in Sect. V-A there are few intrinsically chiral stractures (254) and even fewer that can be obtained from achiral monomers. With two exceptions, which will be dealt with at the end of this section, optically active polymers have been obtained only from 1- or 1,4-substituted butadienes, fiom unsaturated cyclic monomers, fiom substituted benzalacetone, or by copolymerization of mono- and disubstituted olefins. The corresponding polymer stmctures are shown as formulas 32 and 33, 53, 77-79 and 82-89. These processes are called asymmetric polymerizations (254, 257) the name enantiogenic polymerization has been recently proposed (301). 

Terpolymerization, the simultaneous polymerization of three monomers, has become increasingly important from the commercial viewpoint. The improvements that are obtained by copolymerizing styrene with acrylonitrile or butadiene have been mentioned previously. The radical terpolymerization of styrene with acrylonitrile and butadiene increases even further the degree of variation in properties that can be built into the final product. Many other commercial uses of terpolymerization exist. In most of these the terpolymer has two of the monomers present in major amounts to obtain the gross properties desired, with the third monomer in a minor amount for modification of a special property. Thus the ethylene-propylene elastomers are terpolymerized with minor amounts of a diene in order to allow the product to be subsquently crosslinked. 

Another important use of BC13 is as a Friedel-Crafts catalyst in various polymerization, alkylation, and acylation reactions, and in other organic syntheses (see Friedel-Crafts reaction). Examples include conversion of cydophosphazenes to polymers (81,82) polymerization of olefins such as ethylene (75,83—88) graft polymerization of vinyl chloride and isobutylene (89) stereospecific polymerization of propylene (90) copolymerization of isobutylene and styrene (91,92), and other unsaturated aromatics with maleic anhydride (93) polymerization of norbomene (94), butadiene (95) preparation of electrically conducting epoxy resins (96), and polymers containing B and N (97) and selective demethylation of methoxy groups ortho to OH groups (98). 

The first free radical initiated copolymerization was described by Brubakerl) in a patent. A variety of peroxides and hydroperoxides, as well as, 02, were used as initiators. Olefins that were copolymerized with CO included ethylene, propylene, butadiene, CH2=CHX (X—Cl, OAc, CN) and tetrafluoroethylene. A similar procedure was also used to form terpolymers which incorporated CO, C2H4 and a second olefin such as propylene, isobutylene, butadiene, vinyl acetate, tetrafluoroethylene and diethyl maleate. In a subsequent paper, Brubaker 2), Coffman and Hoehn described in detail their procedure for the free radical initiated copolymerization of CO and C2H4. Di(tert-butyl)peroxide was the typical initiator. Combined gas pressures of up to 103 MPa (= 15,000 psi) and reaction temperatures of 120—165 °C were employed. Copolymers of molecular weight up to 8000 were obtained. The percentage of CO present in the C2H4—CO copolymer was dependent on several factors which included reaction temperature, pressure and composition of reaction mixture. Close to 50 mol % incorporation of CO in the copolymer may be achieved by using a monomer mixture that is >70 mol% CO. Other related procedures for the free radical... 

Acrylonitrile (CH2=CH-CN) was made from acetylene and HCN until the 1960s. Today it is made by direct ammoxidation of propylene. Its major use is in making polyacrylonitrile, which is mainly converted to fibers (Orion). It is also copolymerized with butadiene and styrene to produce high impact plastics. 

D. Hirooka gelang es, auch alternierende Copolymere des Acrylnitrils mit Olefinen, u.a. Athylen und Propylen, herzustellen 133>. Altemie-rende Copolymere des Athylens mit Butadien erhielt G. Natta 13S> und fiber alternierende Copolymere des Propylens mit Butadien berichtet Furukawa 136>. 

Vinyl chloride can be copolymerized with a series of monomers Vinylidene chloride, trans-dichloroethylene, vinylesters of aliphatic carboxylic acid (C2-C18), acrylic acid esters, methacrylic and/or maleic acid as well as fumaric acid with mono-functional aliphatic saturated alcohols (Cj-C18), mono-functional aliphatic unsaturated alcohols (C8—C18), vinyl ethers from mono-functional aliphatic saturated alcohols (C i-Cis), propylene, butadiene, maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid (total < 8 %) and N-cyclohexylmaleinimide (< 7 %). 

Catalysts of the Ziegler-Natta type are applied widely to the anionic polymerization of olefins and dienes. Polar monomers deactivate the system and cannot be copolymerized with olefins. J. L. Jezl and coworkers discovered that the living chains from an anionic polymerization can be converted to free radicals by the reaction with organic peroxides and thus permit the formation of block copolymers with polar vinyl monomers. In this novel technique of combined anionic-free radical polymerization, they are able to produce block copolymers of most olefins, such as alkylene, propylene, styrene, or butadiene with polar vinyl monomers, such as acrylonitrile or vinyl pyridine. 

In the present paper we pay special attention to block polymers with polypropylene and polyethylene as the initial anionic block. However, both crystalline and amorphous block polymers of ethylene and propylene, butadiene, and several other olefins and dienes have been made by the AFR technique. The second or free radical block has been made from 4-vinylpyridine, 2-methyl-5-vinylpyridine, and mixtures with other monomers, as well as a number of acrylic monomers. Vinyl chloride, vinylidine chloride, vinyl acetate, and several related monomers have not been successfully copolymerized. 

Note Ethylene may be copolymerized with varying percentages of other materials, e.g., 2-butene or acrylic acid a crystalline product results from copolymerization of ethylene and propylene. When butadiene is added to the copolymer blend, a vulcan-izable elastomer is obtained. 

Polymerization of vinyl chloride Polyacrylates and polymetiiacrylates Butadiene, isopreal and tiien copolymers Cationic copolymerization of isobutene-isoprene with slurry AICI3 as tiie initiator and metiiyl chloride as diluent AICI3 slurry polymerization of propylene in tiie presence of transition metiiyl catalyst and excess monomer as a diluent Fluidized bed reactor is used in tiie gas phase poljmierization a powdered polymer is produced in a gaseous monomer-low pressure poljmierization of ethylene (HDPE) and propylene... 

Another example of ionic graft copolymerization is a reaction carried out on pendant olefinic groups using Ziegler-Natta catalysts in a coordinated anionic-type polymerization. The procedure consists of two steps. In the first, diethylaluminum hydride is added across the double bonds. In the second the product is treated with a transition metal halide. This yields an active catalyst for polymerizations of a-olefms. By this method polyethylene and polypropylene can be grafted to butadiene styrene copolymers. Propylene monomer polymerization results in formations of isotactic polymeric branches ... 

In the free radical polymerization of vinyl acetate, CH2=CH(OOCCH3), on the other hand, there are weak dipole-dipole interactions between the ester groups in the transition state, which facilitates an occasional attack on the a-carbon atom despite steric hindrance by these groups. Poly(vinyl acetate) therefore contains l%-2% head-to-head structures, that is, the ajP orientation ratio is 0.01-0.02. The orientation ratio depends on the attacking species, as well as on the nature of the attacked monomer (Table 15-3). The attack is even almost exclusively at the a position with certain initiators, as, for example, in the copolymerization of butadiene and propylene with certain modified Ziegler catalysts. 

The complexation with Lewis acids alters both the polarity and the resonance stabilization of the electron-accepting monomer (see Table 22-8). So, the change in Q and e values does not necessarily result from a change in the bonding state of the double bond alone. The change may also result from an alteration in the direction of attack on the double bond. For example, the of-carbon atom, and not the more usually attacked /3-carbon atom, is attacked in the copolymerization of butadiene with propylene under the influence of VCU/EtsAl. 

All diene rubbers discussed so far, natural rubber, styrene-butadiene rubbers, poly-butadienes), butyl rubbers, and ethylene-propylene rubbers, consist of aliphatic or aromatic monomeric units. They swell readily in aliphatics they have poor oil resistance. But the free radical copolymerization of acrylonitrile with butadiene leads to what is known as nitrile rubber, which has good oil resistance because of the many polar nitrile groups. However, the rebound elasticity and the low-temperature flexibility decrease with increasing nitrile fraction. Consequently, NBR is mainly used for fuel hoses, motor gaskets, transport belts, etc. 

In some polymer families, copolymerization with more flexible comonomer units is very effective in producing the amount of flexibility desired. Major commercial examples are ethylene/propylene rubber, styrene/butadiene plastics and latex paint, vinyl chloride/ vinyl acetate plastics, vinyl acetate/acrylic ester latex paints, and methyl methacrylate/ acrylic ester plastics and latex paints. 

Apart from the major reviews, numerous publications have appeared in the last two years which report new monomer combinations for alternating copolymerization or which seek to throw light on the numerous problems which still exist in this burgeoning field of study. Many comonomer systems have been reported in the last two years which give rise to alternating copolymers by one or more of the mechanisms which have been outlined, including acrylonitrile with acenaphthalene, cyclopenta-1,3-diene p-aminostyrene with p-nitro-styrene and other vinyl monomers butadiene with 1,2-dicarbomethoxy ethylenes, acrylonitrile, propylene, and others isoprene with mono-... 

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