Monomer preparation

Vinyl ethers are prepared in a solution process at 150—200°C with alkaH metal hydroxide catalysts (32—34), although a vapor-phase process has been reported (35). A wide variety of vinyl ethers are produced commercially. Vinyl acetate has been manufactured from acetic acid and acetylene in a vapor-phase process using zinc acetate catalyst (36,37), but ethylene is the currently preferred raw material. Vinyl derivatives of amines, amides, and mercaptans can be made similarly. A/-Vinyl-2-pyrroHdinone is a commercially important monomer prepared by vinylation of 2-pyrroHdinone using a base catalyst. 

Various inorganic, organic, and organometaUic compounds are known to cataly2e this polymerization (4,8,9). Among these, BCl is a very effective catalyst, although proprietary catalysts that signiftcandy lower polymerization temperature from the usual, sealed-tube reaction at 250°C are involved in the industrial manufacture of the polymer. A polycondensation process has also been developed for the synthesis of (4) (10—12). This involves elimination of phosphoryl chloride from a monomer prepared from (NH 2 04 and PCl. ... 

The poly(vinyl ethers), whieh were first made available in Germany before 1940, are not of importance in the plastics industry but have applications in adhesives, surfaee coatings and rubber technology. Of the many vinyl ether polymers prepared, only those from the vinyl alkyl ethers and some halogenated variants are of interest. Two methods of monomer preparations may be used. 

Wakselman C. FluoroacryUc Esters and Related Monomers Preparation and Use As Synthons MacromoL Symp. 1994 82 77-S7... 

Velichkova, R. S., Toncheva, V. D., and Panayotov, I. M., Macromonomers fi om vinyl and cyclic monomers prepared by initiation with stable carbenium salts, J. Polym. Sci., Part A Polym. Chem.. 25. 3283-3292, 1987. 

Polymer and monomer preparation, purification and handling have been described in other reports from this laboratory (3,6,10). 

The azide monomer, prepared in solution from the chlorophosphine and sodium azide, should not be isolated because it is potentially explosive. 

Patents of Dow Chemicals first described 9,9-diaryl-substituted PF homopolymers 204 and 205 by Yamamoto polymerization of the corresponding 2,7-dibromo monomers [272], although the methods for monomer preparation were not described. For unsubstituted fluorenone, a convenient method for its conversion into 9,9-(4-hydroxyphenyl)-[307-309] and 9,9-(4-alkoxyphenyl)fluorenes [310] was reported previously, which included condensation of fluorenone with phenol or its ethers in acidic conditions (dry HC1 [308,309] or H2SO4 [307,311]) in the presence of (3-mcrcaptopropionic or mercaptoacetic acids. Both polymers 204 and 205 showed similar Mn 21,000 with PDI of 1.48 and 1.75, respectively, and spectral data typical for PF (205 Aabs = 389 (r 50,000 //(mol cm) APL = 417, 439, and 473 mn (THF)) (Chart 2.48). 

Only two typical examples in monomer preparation are described here. 

Tetrafluoroethylene-(TFE)-perfluoropropyl vinyl ether copolymers, 7 641 Tetrafluoroethylene-perfluorovinyl ether, 48 329-339. See also Teflon PFA copolymerization of, 48 330—331 Tetrafluoroethylene-perfluorodioxole copolymers, 48 339—342. See also Teflon AF copolymers applications of, 48 342 economic aspects of, 48 341—342 health and safety factors related to, 48 342 monomer preparation, 48 339 synthesis of, 48 339-340 Tetrafluoroethylene (TFE) copolymerization with... 

Monomer Preparation, my]. Balsamic ftci-fl—Allyl amine (84.4 g 1.481 mol) in 100 mL of dichloromethane was added dropwise to recrystallized maleic anhydride (132 g 1.348 mol) in 500 mL of dichloromethane at room temperature. The reaction mixture was stirred for 2 hr at room temperature and then filtered to obtain 206 g (99% of theory) of pale yellow crystals, m.p. 110-112°C. 

A spontaneous polymerization of glucose methacrylate, however, is observed during the monomer preparation without gel formation and a very hydrophilic water soluble polymer with high viscosity is obtained by precipitation in acetone. This procedure requires further improvement. 

TABLE 1. Selected Spirobifluorene Monomers Prepared in Three Reaction Steps for Subsequent Conversion into Spirobifluorene Copolymer by Yamamato Coupling... 

AB maleimide benzocyclobutene monomers and polymers have also been actively studied and developed by researchers at the Dow Chemical Co. The first AB maleimide type benzocyclobutene monomer prepared and polymerized by Kirchhoff was the benzocyclobutenyl maleamic acid 106 [6]. The detailed synthesis of 106 is shown in Fig 44. 

Another approach to the preparation of AB maleimide benzocyclobutenes was to use the parent hydrocarbon as the primary building block. One of the first monomers prepared directly from the hydrocarbon was 17, which was a material that was later reported on by researchers at Air Force Wright Laboratories [103]. 

Fluoroacrylic Esters and Related Monomers Preparation and Use as Synthons Wakselman, C. Macromol. Symp. 1994. 82, 77-87. 

Nitta, T, Yagita, H., Azuma, T., Sato, K, and Okomura, K (1989) F(ab )2 monomer prepared with anti-CD3 and anti-tumor monoclonal antibodies is most potent in induction of cytolysis of human T cells. Eur. J. Immunol. 19, 1437-1441... 

As utilized in the synthesis of PPV-based polymers, soluble precursor routes have been developed for the synthesis of various heterocyclic Jt-conjugated polymers. The two most widely employed of these methods for heterocycle formation, shown in Scheme 66, center around ring closure of pre-polymers containing diacetylene 65 or 1,4-diketone units 66 [335-339]. The synthesis of heterocyclic structures from 1,4-diketones has been a known transformation in organic chemistry for decades. While once mainly used for monomer preparation through various cyclizations, it is now being employed to make heterocycle-containing polymers and copolymers [340-342]. 

Willow-like cascade construction was facilitated by the preparation of the AB2-type building blocks, e.g., 6-bromo-l-(4-hydroxy-4 -biphenylyl)-2-(4-hydroxyphenyl)hexane (40 Scheme 6.12), 13-bromo-l-(4-hydroxyphenyl)-2-[4-(6-hydroxy-2-naphthalenylyl)-phenyljtridecane (41), and 13-bromo-l-(4-hydroxyphenyl)-2-(4-hydroxy-4"-p-terpheny-lyl)tridecane (42). Scheme 6.12 illustrates the monomer preparative strategy for the incorporation of the monomeric mesogenic moieties predicated on conformational (gauche versus anti) isomerism. Thus, one equivalent of 4-hydroxybiphenyl was allowed to react with 1,4-dibromobutane to yield the monobromide 43, which was converted under Finkelstein conditions to the corresponding iodide 44. Treatment of the latter with ketone 45 under phase transfer conditions afforded the a-substituted ketone 46. Reduc-... 

Scheme 6.12. Monomer preparation for the construction of liquid crystalline polymers.

Sharpless et al.l20b have constructed chiral dendrimers by employing the doubleexponential synthetic method.[20c] Chirality was induced via the use of aryl acetonide monomers prepared by asymmetric dihydroxylation (AD) of the corresponding prochiral alkenes. Each monomeric unit possessed two asymmetric carbons. Examples described are C3-symmetric and contain up to 45 chiral building blocks with 24 acetonide termini. 

Monomer Preparation. The hexamethylcyclotrisiloxane used in these experiments was supplied through the courtesy of W. L. Robb of the Silicone Products Department, General Electric Co. It was purified through repeated sublimation and recrystallization and exhibited, by VPC analysis, an impurity level of less than 1 part in 1000. (m.p., 64.5°C.)... 

TABLE 1. Selected bisthiophene-finorene copolymers and monomer prepared according to the current invention. 

TABLE 1. Selected monomers prepared by condensing pentafluoropropyl alcohol with methacryloyl or acryloyl chloride. 

Emulsion Polymerization of Multifimctional Monomers-Preparation of Reactive Microgels... 

Vinyl Monomer Preparation. The vinyl monomers (Matheson, Coleman, and Bell) were treated as follows Acrylonitrile was dried over calcium chloride and distilled twice vinyl acetate was purified by distillation, and both monomers were stored under refrigeration and redistilled before use. Vinyl chloride was used directly from the lecture bottle in which it was obtained. 

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