Free radical copolymerization terpolymerization

Iwatsuki and Yamashita (46, 48, 50, 52) have provided evidence for the participation of a charge transfer complex in the formation of alternating copolymers from the free radical copolymerization of p-dioxene or vinyl ethers with maleic anhydride. Terpolymerization of the monomer pairs which form alternating copolymers with a third monomer which had little interaction with either monomer of the pair, indicated that the polymerization was actually a copolymerization of the third monomer with the complex (45, 47, 51, 52). Similarly, copolymerization kinetics have been found to be applicable to the free radical polymerization of ternary mixtures of sulfur dioxide, an electron donor monomer, and an electron acceptor monomer (25, 44, 61, 88), as well as sulfur dioxide and two electron donor monomers (42, 80). 

Some characteristics of free-radical terpolymerization of tri-butylstannyl methacrylate, styrene and maleic anhydride governed by the pentacoordination state of the tin atom are reported in Refs. 95),96). It is shown that a coordination-bound monomer has a considerable effect on chain initiation and propagation. Copolymerization mainly involves the participation of complex-bound monomers. 

The two monomers enter into the copolymer in overall amounts determined by their relative concentrations and reactivities. The chain copolymerization may, however, be initiated by any of the chain initiation mechanisms, namely, free-radical chain initiations considered in the preceding chapter, or ionic chain initiations, which will be described in a later chapter. Chain copolymerizations involving more than two monomers are generally referred to as multicomponent copolymerizations. For systems of three monomers, the specific term terpolymerization is commonly used. 

Figure 22-1. Change in mole fraction of acrylonitrile (AN), butyl acrylate (BA), and butadiene (BU) in monomer mixture (atm ") and in copolymer (x ) as a function of yield for the free radical terpolymerization of an [AN]o [BA]o [BU]o - 0.5 0.25 0.25 mixture at 60 C. The copolymerization parameters are rANBU = 0.1, 2- buba 9.9, tbuan 3.5,...

Table 22 5. The Product of the Binary Copolymerization Parameters for the Free Radical Terpolymerization of the Conjugated Monomers Methyl Acrylate, Methyl Methacrylate, Acrylonitrile, and Styrene, as well as for the Nonconjugated Monomers Vinyl Acetate, Vinyl Chloride, and Vinylidene Chloride...

He et al. have prepared phosphonated aiyl trifluorovinyl ethers containing flexible oligo(ethylene oxide) units and subsequently homopolymerized these monomers by thermal cyclopolymerization in bulk at 180 °C. The resulting polymer was treated with bromotrimethylsilane to obtain the phosphonic acid derivative. The phosphonated trifluorovinyl ether monomers were also copolymerized with tetrafluoroethylene via free radical pol3Tnerization in an autoclave at 70 °C using l,l,2-trichloro-l,2,2-tri-fluoroethane as solvent. Moreover, radical terpolymerizations of the same trifluorovinyl ether monomers were performed with mixtures of... 

The ceiling temperature constraint in the homopolymerization of alphamethyl styrene (AMS) can be circumvented by copolymerization with acrylonitrile (AN) to prepare multicomponent random microstructures that offer higher heat resistance than SAN. The feasibility of a thermal initiation of free radical chain polymerization is evaluated by an experimental study of the terpolymerization kinetics of AMS-AN-Sty. Process considerations such as polyrates, molecular weight of polymer formed, sensitivity of molecular weight, molecular weight distribution, and kinetics to temperature were measured. 

A fluorinated monomer susceptible to copolymerizing or terpolymerizing vinylidene fluoride is needed to undergo free-radical attack to render peroxide curable elastomeric co- or terpolymers of VDF [35]. So, this monomer must be functionalized or halogenated to ensure a free-radical crosslinking. The monomers mainly used are bromine-containing fluoroolefins such as [42,43] ... 

Abz-(Cd)MAm] (Scheme 5) [56]. The terpolymers of AMPS-LaMAm— Abz-(La)MAm and AMPS-CdMAm-Abz(Cd)MAm are synthesized by free-radical terpolymerization initiated by AIBN in a manner analogous to the copolymerization procedures detailed in the previous section. The Abz moieties are substituted with bulky hydrophobic groups that are the same as those in the polymers to ensure that the Abz residues are incorporated into the hydrophobic microdomains formed by the hydrophobes and the motional freedoms of the Abz residues are directly affected by the hydrophobic microenvironments. 

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. 

CH3)3CO— is an initiator residue]. With copolymerization of free monomers, they should have observed an increasing A/B ratio according to the method used with complex propagation, A/B should remain constant. The authors observed both cases. They concluded that maleic anhydride with a monomeric donor, like styrene, yields a DA complex by a reversible reaction, with an equilibrium constant of 10-1 to 10-2 dm3 mol-1. The initiating radical is formed from the complex, and the copolymerization is in fact a terpolymerization involving the two free monomers and their complex. These authors have applied the same technique in a study of the type of radicals formed in copolymerization of maleic anhydride with vinyl sulphides. Even in this case they provided evidence of the existence of a complex. 

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