Lactam ethers, polymerization

It has also been known that the polymerization of some bicyclic lactam ethers, for example, 3-aza-10-oxabicyclo[4.3.1]decan-4-one 60 was accompanied by the cleavage of the ether bond55,56. ... 

Polymerization of seven-membered lactam ethers [73] and lactam thioethers [74, 75]... 

When lactones copolymerize with cyclic ethers, such as j -ptopiolactone with tetrahydrofiiran, in the early steps of the reaction the cyclic ethers polymerize almost exclusively. This is due to the greater basicity of the ethers. When the concentration of the cyclic ethers depletes to the equilibrium value, their consumption decreases markedly. Polymerizations of the lactams com-mence. The products are block copolymer. 

The number of monomers that undergo chain-growth polymerization is large and includes such compounds as alkenes, alkynes, allenes, isocyanates, and cyclic compounds such as lactones, lactams, ethers, and epoxides. We concentrate on the chain-growth polymerizations of ethylene and substituted ethylenes and show how these compounds can be polymerized by radical and organometallic-mediated mechanisms. 

Monomers used for chain-growth polymerization include alkenes, alkynes, allenes, isocyanates, and cyclic compounds such as lactones, lactams, ethers, and epoxides. 

In addition to step and chain polymerizations, another mode of polymerization is of importance. This is the ring-opening polymerization (ROP) of cyclic monomers such as cyclic ethers, acetals, amides (lactams), esters (lactones), and siloxanes. Ring-opening polymerization is of commercial interest in a number of systems, including the polymerizations of ethylene oxide... 

A survey of the literature reports regarding the synthesis of (3-lactam using carbohydrate precursors has recently been published by Furman et al. [215]. They have shown that the carbohydrates were used either as chiral tools or chiral auxiliaries. A few solid phase approaches have been outlined in the survey using the vinyl ether bound to the polymeric support through a sulfonyl linker. Two alternative modes of attachment of the vinyl ethers to the resin have been reported. 

The second type of monomer for step-growth polymerization contains two different functional groups. Examples in this category include hydroxy acids such as lactic acid (or hydroxy esters [Equations 1-3]), and amino acids. A third type includes cyclic monomers such as lactones, lactams, and cyclic ethers. Cyclic monomers polymerize by ring-opening polymerization. Some, as we said, proceed by step-growth and some by chain-growth mechanisms. 

The same name would ordinarily be used even if the polymer were synthesized from ethylene glycol (HOCH2CH2OH), ethylene chlorohydrin (CICH2CH2OH), or bischloromethyl ether (CICH2OCH2CI). Similarly, structure 1-13 is called polycaprolactam because it is made industrially from the lactam by reaction (1-5), in preference to polymerization of the parent amino acid, H2N (CH2).[Pg.29]

Some cyclic amines, iminoethers, sulfides, ethers, esten, and acetals were indeed demonstrated to polymerize without appreciable transfer and/or termination. It cannot be excluded that for monomers belonging to other compound classes, e.g. lactams or cyclic esters of phosphoric acid, the conditions for the transfer- and terminationless processes will be found in the near future. 

Volume 15 deals with those polymerization processes which do not involve free radicals as intermediates. Chapters 1 and 2 cover homogeneous anionic and cationic polymerization, respectively, and Chapter 3 polymerizations initiated by Zeigler-Natta and related organometallic catalysts. Chapters 4, 5 and 6 deal with the polymerization of cyclic ethers and sulphides, of aldehydes and of lactams, respectively. Finally, in Chapter 7 polycondensation reactions, and in Chapter 8 the polymerization of AT-carboxy-a-amino acid anhydrides, are discussed. 

A special type of polymerization is that of cyclic compounds such as lactones, lactams, cyclic ethers, cyclic anhydrides, or cyclic N-carboxyanhydrides that can be polymerized by ionic mechanisms. These compounds can undergo an addition reaction with characters of both chain and step polymerization. 

Thus, we first discuss thermodynamics, paying attention to features that are important for polymer synthesis (e.g., dependence of equilibrium monomer concentration on polymerization variables) then we describe kinetics and thermodynamics of macrocyclization, trying to combine these two related problems, usually discussed separately. In particular we present the new theory of kinetic enhancement and kinetic reduction in macrocyclics. Thereafter, we describe the polymerization of several groups of monomers, namely cyclic ethers (oxiranes, oxetanes, oxolanes, acetals, and bicyclic compounds) lactones, cyclic sulfides, cyclic amines, lactams, cyclic iminoethers, siloxanes, and cyclic phosphorus-containing compounds, in this order. We attempted to treat the chapters uniformly we discuss practical methods of synthesis of the corresponding polymers (monomer syntheses and polymer properties are added), and conditions of reaching systems state and reasons of deviations. However, for various groups of monomers the quality of the available information differ so much, that this attempt of uniformity can not be fulfilled. 

Besides the thermodynamic feasibility, there should also be a kinetic pathway for the ring to open, facilitating polymerization. Cycloalkanes, for example, have no bond in the ring structiire that is prone to attack and thus lack a kinetic pathway. This is in marked contrast to the cyclic monomers such as lactones, lactams, cyclic ethers, acetals, and many other cyclic monomers that have a heteroatom in the ring where a nucleophilic or electrophilic attack by an initiator species can take place to open the ring and initiate polymerization. Both thermodynamic and kinetic factors are thus favorable for these monomers to polymerize (Odian, 1991). 

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