Propylene copolymerization with ethylene

Random copolymerization of propylene oxide with ethylene oxide proceeded smoothly with the Nd(2-EP)3/AlEt3/H20 system at 80 °C [59]. From... 

In a recent patent, Reuter (110) describes a polyurethane prepared from PTHF (mol. wt. 1000 to 3000), 1,4-butanediol, and OCN(CH2)6CN0. In another case Murbach and Adicoff (67) interrupted the regularity of PTHF by copolymerization with ethylene oxide before chain extension with diphenyl-methane-4,4 -disiocyanate. Dickinson (99) prepared a series of polyurethane elastomers from THF-PO copolymer diols and 2,4-tolylene diisocyanate. He found that the use of copolymers with approximately 75 wt.-% THF led to polyurethanes with very good properties relative to the use of propylene oxide homopolymer. 

In the patent literature, there are several reports of the cationic polymerization of tetrahydrofuran (THF) with Nafion-H. In most cases, small amounts of acetic anhydride were added so the initial polymer had a terminal acetate group that could be hydrolyzed to the free hydroxyl. THF has also been homopolymerized936 938 and copolymerized with ethylene oxide and propylene oxide in the presence of Nafion-... 

Although they lack commercial importance, many other poly(vinyl acetal)s have been synthesized. These include acetals made from vinyl acetate copolymerized with ethylene (43—46), propylene (47), isobutylene (47), acrylonitrile (48), acrolein (49), acrylates (50,47), allyl ether (51), divinyl ether (52), maleates (53,54), vinyl chloride (55), diallyl phthalate (56), and starch (graft copolymer) (47). 

Butene-1 can be copolymerized with ethylene as well as higher a-olefins like propylene and 4-methyl-pentane. 

Unconjugated dienes can produce an even more complicated range of macro-molecular structures. Homopolymers of such monomers are not of current commercial importance but small proportions of monomers like 1,5-cyclooctadicne are copolymerized with ethylene and propylene to produce so-called EPDM rubbers. Only one of the diene double bonds is enchained when this terpolymeriza-tion is carried out with Ziegler-Natta catalysts (Section 9.5). The resulting small amount of unsaturation permits the use of sulfur vulcanization, as described in Section 1.3.3. 

In order to introduce LCBs of different structures, vinyl-terminated olefin oligomers have been used in copolymerization with ethylene (as well as propylene, see Section 4.09.4.2.8). Such macromonomers can be prepared by ethylene oligomerization,531,567 E/P co-oligomerization,568 or propylene oligomerization.569 In the last case, a catalyst with a very high selectivity for /3-Me transfer is necessary, in order to produce oligomers with the required Q-olefinic terminal. 

The copolymerization of ethylene with nonconjugated dienes is of significant interest due to its applicability to ethylene-propylene-diene rubber (EPDM) [84]. The cyclic dienes such as 1,3-cyclopentadiene, dicyclopen-tadiene, and vinylcyclohexane copolymerize with ethylene catalyzed by rac-Et(Ind)2ZrCl2/MAO (Eq. 16) [85]. 

The introduction of sulfonate groups into EPDM occurs via an electrophilic attack of the sulfonation reagent on the unsaturation in EPDM. Many termonomers can be copolymerized with ethylene and propylene to produce EPDM s with a variety of residual olefinic types (II). All of the EPDM s in this study were produced from ENB. Since the incorporation of ENB into the polymer chain during copolymerization... 

Vizen,Ye.V., Kissin, Yu.V. Composition distribution for copolymers in ethylene-propylene copolymerization with the heterogeneous catalyst system VC13-A1(C2H6)3. Vysokomol. Soyed. A, 11, 1774-1782 (1969). - Polymer Sci. USSR A, 11,2017-2028 (1969). 

The efficiency of this process is usually less than one cross-link per peroxide molecule decomposed. To increase the cross-linking efficiency, small amounts of unsaturation are introduced into the polymer structure. We have already discussed EPDM polymers, which are essentially diene monomers copolymerized with ethylene-propylene (EPR) polymers. For polysiloxanes, copolymerization of small amounts of vinyl-methylsilanol greatly enhances cross-linkability (Equation 5.7). The unsaturation introduced into an otherwise saturated structure provides additional sites for cross-linking through chain reaction. 

The major commercial use of propylene oxide is as a comonomer for copolymerization. The block copolymerization with ethylene oxide produces water-soluble detergents. The copolymerization of propylene oxide with non-conjugated dienes produces sulfur-vulcanizable, oil-resistant elastomers that remain rubber-like at low temperatures. The elastomers obtained by the copolymerization of propylene oxide with allyl glycidyl ether have only poor oil resistance, but have good ozone resistance and remain rubberlike at low temperatures. 

When propylene (P) is copolymerized with ethylene (E), the copolymerization parameters and are excellent measures for the olefin sequence distribution as shown below for different copolymer sequences ... 

Another commercially important reaction is du Font s synthesis of 1,4-hexadiene. This is converted to synthetic rubber by copolymerization with ethylene and propylene, which leaves the polymer with unsaturation. This is present in natural rubber, a 2-methylbutadiene polymer 11.32, and is necessary for vulcanization. 

This macromonomer has been copolymerized with ethylene and propylene in the presence of Ziegler-Natta catalysts. 

FIGURE 7.23 Experimental (Exp.) and computed (Current) triad distributions for ethylene/propylene copolymerization with 8 show good agreement. 

Thermoplastic Polyolefin n (TPO) Any of a group of elastomers produced by either of two processes. In one, polypropylene is melt-blended with from 15% to 85% of terpolymer elastomer, ethylenepropylene rubber, or styrene-butadiene rubber. In the other, propylene is copolymerized with ethylene-propylene elastomer in a series of reactions. The smaller elastomeric domains obtained in the latter process are claimed to provide improved properties over the blended materials. 

We have reported homopolymerization of propylene and its copolymerization with ethylene using catalyst 4/MAO systems [92]. Isotactic polypropylene obtained with catalyst 4/MAO catalyst systems in the range of reaction temperature from —30°C to 50°C was successively fractionated by boiling pentane, hexane, heptane, and trichloroethylene. It was found that the hexane-insoluble/heptane-soluble portion was the major fraction for all samples. The whole and fractionated polymers were characterized in comparison to those obtained with MgCl2/TiCl4-Et3Al catalyst system by NMR, GPC, and DSC. The C NMR spectrum of the Zr system exhibited a number of... 

Extending the a-olefin to RCH = CH2, where R is a C2—Cg alkyl group, one obtains copolymers with superior processibility and physical properties, including high creep resistance and low cold flow [30c,d]. Many other cyclic and polycyclic dienes have been copolymerized with ethylene, propylene, and various a-olefins using conventional Ziegler-Natta catalysts. Of these, compounds (34-40) yield products displaying attractive physico-mechanical parameters [30e-l]. 

Examples of stereoelective copolymerization have been reported. Matsuura, Tsuruta, Terada, and Inoue (156) prepared a polyester from 3-phenyl-A -tetrahydrophthalic acid anhydride and propylene oxide using diethyl zinc-(+)borneol as an optically active catalyst and obtained an optically active polyester. The authors reported that the stereoelective copolymerization of 3-phenyl-tetrahydrophthalic acid anhydride had occurred, but that of propylene oxide was not observed. Kximata, Furukawa, and Saegusa (157) copolymerized racemic propylene oxide with ethylene oxide using the ZnEt2/(+)-borneol system, and found that stereoelectivity of propylene oxide was not hindered by the occurrence of an ethylene oxide unit at the end of the growing chain. 

Kennedy and co-workers have synthesized macromonomers from isobutylene using the inifer technique,which will be described in more detail in Section 9.4.4.3. Two typical examples are given in Scheme 15. The second macromonomer was copolymerized with ethylene and propylene in the presence of Ziegler-Natta type catalysts. 

Other interesting perfluoro ether stmctures can be obtained by copolymerization of hexafluoroacetone with ethylene oxide, propylene oxide, and trimethylene oxide with subsequent fluorination to yield the following stmctures (67) ... 

Uses. Besides polymerizing TFE to various types of high PTEE homopolymer, TEE is copolymerized with hexafluoropropylene (29), ethylene (30), perfluorinated ether (31), isobutylene (32), propylene (33), and in some cases it is used as a termonomer (34). It is used to prepare low molecular weight polyfluorocarbons (35) and carbonyl fluoride (36), as well as to form PTEE m situ on metal surfaces (37). Hexafluoropropylene [116-15-4] (38,39), perfluorinated ethers, and other oligomers are prepared from TEE. 

Propylene oxide can be copolymerized with other epoxides, such as ethylene oxide (qv) (25,29,30) or tetrahydrofiiran (31,32) to produce copolymer polyols. Copolymerization with anhydrides (33) or CO2 (34) results in polyesters and polycarbonates (qv), respectively. 

Propylene can be polymerized alone or copolymerized with other monomers such as ethylene. Many important chemicals are based on propylene such as isopropanol, allyl alcohol, glycerol, and acrylonitrile. Chapter 8 discusses the production of these chemicals. U.S. production of proplylene was approximately 27.5 billion lbs in 1997. ... 

Ethylene reacts by addition to many inexpensive reagents such as water, chlorine, hydrogen chloride, and oxygen to produce valuable chemicals. It can be initiated by free radicals or by coordination catalysts to produce polyethylene, the largest-volume thermoplastic polymer. It can also be copolymerized with other olefins producing polymers with improved properties. Eor example, when ethylene is polymerized with propylene, a thermoplastic elastomer is obtained. Eigure 7-1 illustrates the most important chemicals based on ethylene. 

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