Copolymerization terpolymers

Uses. Vinyhdene fluoride is used for the manufacture of PVDF and for copolymerization with many fluorinated monomers. One commercially significant use is the manufacture of high performance fluoroelastomers that include copolymers of VDF with hexafluoropropylene (HFP) (62) or chlorotrifluoroethylene (CTFE) (63) and terpolymers with HEP and tetrafluoroethylene (TEE) (64) (see Elastomers, synthetic-fluorocarbon elastomers). There is intense commercial interest in thermoplastic copolymers of VDE with HEP (65,66), CTEE (67), or TEE (68). Less common are copolymers with trifluoroethene (69), 3,3,3-trifluoro-2-trifluoromethylpropene (70), or hexafluoroacetone (71). Thermoplastic terpolymers of VDE, HEP, and TEE are also of interest as coatings and film. A thermoplastic elastomer that has an elastomeric VDE copolymer chain as backbone and a grafted PVDE side chain has been developed (72). 

ABS is the sixth largest volume thermoplastic resin and the principal engineering (stmctural or load bearing) plastic (89). ABS is a terpolymer manufactured by copolymerizing acrylonitrile and styrene in the presence of polybutadiene mbber. Important producers of ABS plastics include General Electric, Monsanto (Lustran), and Dow (Abtec) (see Acrylonitrile polymers). 

Polymer Composition. Ethylene—acrylic elastomer terpolymers ate manufactured by the addition copolymerization of ethylene [74-85-1] and methyl acrylate [96-33-3] in the presence of a small amount of an alkenoic acid to provide sites for cross-linking with diamines (4). 

New copolymers based on a copolymerization of isobutylene and p-methyl-styrene with improved heat resistance have been reported [64]. Once copolymerization was accomplished, the polymer was selectively brominated in the p-methyl position to yield a terpolymer called EXXPO. In contrast to butyl and halobutyl, the new terpolymer has no unsaturation in the backbone and therefore shows enhanced thermal stability and resistance to oxidation. Useful solvent-based adhesives can be formulated using the new terpolymer in combination with block copolymers [65]. The hydrocarbon nature of the new terpolymer results in excellent compatibility with hydrocarbon resins and oils. 

The complexity of the terpolymer composition equation (eq. 36) can be reduced to eq. 41 through the use of a modified steady slate assumption (eqs. 38-40), However, while these equations apply to component binary copolymerizations it is not clear that they should apply to terpolymerization even though they appear to work well. It can be noted that when applying the Q-e scheme a terpolymer equation of this form is implied. 

Multiblock copolymeric structures containing PCHD blocks were also synthesized using s-BuLi as the initiator and either TMEDA or DABCO as the additive. Sequential monomer addition was performed with CHD being the last monomer added in all cases [35]. The structures prepared are PS-b-PCHD, PI-fc-PCHD and PBd-b-PCHD block copolymers, PS-fo-PBd-fo-PCHD, PBd-fr-PS-b-PCHD and PBd-fo-PI-fr-PCHD triblock terpolymers, and PS-fc-... 

An allyl samarocene catalyst, [(CMe2C5H4)2SmCl(C3H5)MgCl2(THF)4, was employed for the synthesis of trans-Vl-b-VCL copolymers and poly(fra s-isoprene-co-hex-l-ene)-fr-PCL terpolymers [111]. The copolymerizations... 

Note Copolymers that are obtained by copolymerization of two monomer species are sometimes termed bipolymers, those obtained from three monomers terpolymers, those obtained from four monomers quaterpolymers, etc. 

Because of the enhanced effectiveness of the cobalt(III) complex with piperidinium end-capping arms (Scheme 6) compared to standard (salen)CoX catalysts for the copolymerization of propylene oxide and CO2, Nozaki and coworkers were able to prepare in a stepwise manner a tapered block terpolymer by first copolymerizing propylene oxide/C02 followed by 1-hexene oxide/C02 [31]. 

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. 

Nitrile rubber (NBR), a copolymer of 1,3-butadiene with 20-40% acrylonitrile, is noted for its oil resistance. More than 150 million pounds are produced annually in the United States. Applications include fuel tanks, gasoline hoses, and creamery equipment. Nitrile resin is made by copolymerizing acrylonitrile with about 20-30% styrene or methyl methacrylate in the presence of NBR or SBR rubber to yield a blend of the graft terpolymer and homocopolymer. Applications include extruded and blow-molded containers for household, automotive, and other products as well as some nonbeverage foods (spices, vitamins, candy). 

Copolymerization of two monomers has been very thoroughly investigated, but copolymerization of three or more compounds presents considerable difficulties on account of the multiplicity of variables. Nevertheless, terpolymers (from... 

In an effort to improve PMMA s photosensitivity further, methyl methacrylate has been copolymerized with higher percentages of the a-keto-oxime methacrylate and terpolymerized with varying amounts of methacrylonitrile. The resulting effects on resist properties, e.g., sensitivity, contrast and resolution, and plasma resistance, are reported here. The terpolymers are up to 85 times more sensitive than PMMA, and retain its high resolution characteristics. 

The polymerization of a mixture of more than one monomer leads to copolymers if two monomers are involved and to terpolymers in the case of three monomers. At low conversions, the composition of the polymer that forms from just two monomers depends on the reactivity of the free radical formed from one monomer toward the other monomer or the free radical chain of the second monomer as well as toward its own monomer and its free radical chain. As the process continues, the monomer composition changes continually and the nature of the monomer distribution in the polymer chains changes. It is beyond the scope of this laboratory manual to discuss the complexity of reactivity ratios in copolymerization. It should be pointed out that the formation of terpolymers is even more complex from the theoretical standpoint. This does not mean that such terpolymers cannot be prepared and applied to practical situations. In fact, Experiment 5 is an example of the preparation of a terpolymer latex that has been suggested for use as an exterior protective coating. 

R. Qi, J. Qian, Z. Chen, X. Jin, and C. Zhou, Modification of acrylo-nitrile-butadiene-styrene terpolymer by graft copolymerization with maleic anhydride in the melt. II. Properties and phase behavior, J. Appl. Polym. Sci., 91(5) 2834-2839, March 2004. 

C. Deacon and C.A. Wilkie, Graft copolymerization of acrylic acid on to acrylonitrile-butadiene-styrene terpolymer and thermal analysis of the copolymers, Eur. Polym. J., 32(4) 451-455, April 1996. 

Chemical processes are far more varied and may involve either the formation of radicals or ions along a polymeric backbone. Both cationic processes3 as well as radical processes have been widely used for graft copolymerization of vinyl monomers onto various polymers. Radical graft copolymerization has been reported for many polymers including styrene-butadiene block copolymers, and acrylonitrile-butadiene-styrene terpolymer, ABS.3 7 9... 

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. 

STYRENE-MALEIC ANHYDRIDE. A thermoplastic copolymer made by the copolymerization of styrene and maleic anhydride. Two types of polymers are available—impact-modified SMA terpolymer alloys (Cadon ) and SMA copolymers, with and without rubber impact modifiers (Dylark ). These products are distinguished by higher heat resistance than the parent styrenic and ABS families. The MA functionality also provides improved adhesion to glass fiber reinforcement systems. Recent developments include lerpolymer alloy systems with high-speed impact performance and low-temperature ductile fail characteristics required by automotive instrument panel usage. 

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... 

On the basis of the copolymerization parameters (cf. Sect. 3.2.3) it could be assumed that the incorporation of the azo monomers into the terpolymer was invariably complete and this was also proved experimentally 50, 51 ... 

A terpolymer has been prepared from cyclopentene, sulfur dioxide, and acrylonitrile by Y. Yamashita and co-workers. The mechanism was recognized as a binary copolymerization between a cyclopentene/S02 complex and free acrylonitrile. 

Spontaneous copolymerization of cyclopentene (CPT) with sulfur dioxide (SOt) suggests the participation of a charge transfer complex in the initiation and propagation step of the copolymerization. The ESR spectrum together with chain transfer and kinetic studies showed the presence of long lived SOg radical. Terpolymerization with acrylonitrile (AN) was analyzed as a binary copolymerization between CPT-SOt complex and free AN, and the dilution effect proved this mechanism. Moderately high polymers showed enhanced thermal stability, corresponding to the increase of AN content in the terpolymer. 

Commercial ABS is prepared primarily by free-radical emulsion copolymerization of styrene and acrylonitrile in the presence of polybutadiene latex (3). This method was therefore adapted for the preparation of ABS and MBS terpolymers and an intermediate AMBS tetrapolymer under similar conditions (Table I). Polymerizations were charged into 12-ounce crown-cap bottles, sparged and flushed with nitrogen, and... 

Homopolymers possess only one type of repeat unit in the chain structure. Thus, except for the chain ends, the composition is constant throughout the chain. It is also possible to prepare chemical copolymers, in which two chemically different repeat units are distributed along the chain backbone. In terpolymers, there are three different types of repeat units. A chemically copolymeric polyphosphazene is shown in Figure 2.17. Thus, copolymers involve a composition variable since, for example, an AB copolymer... 

Another widely used copolymer is high impact polystyrene (PS-HI), which is formed by grafting polystyrene to polybutadiene. Again, if styrene and butadiene are randomly copolymerized, the resulting material is an elastomer called styrene-butadiene-rubber (SBR). Another classic example of copolymerization is the terpolymer acrylonitrile-butadiene-styrene (ABS). Polymer blends belong to another family of polymeric materials which are made by mixing or blending two or more polymers to enhance the physical properties of each individual component. Common polymer blends include PP-PC, PVC-ABS, PE-PTFE and PC-ABS. 

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