Poly chloromethylation

Even in solution the relative rigidity of the polymer support can play a significant role in the reactivity of attached functional groups. Contrasting studies conducted with chloromethylated derivatives of poly(arylene ether sulfone) (Tg 175°C), phenoxy resin (Tg= 65°C) and polystyrene (Tg= 105°C) allow evaluation of chain rigidity effects. We have shown that the rates of quaternization of chloromethylated poly(arylene ether sulfones) and phenoxy resin deviate from the anticipated second order process at... 

Sugawara et al. (91,92) have extended their work on chloromethylated polystyrene to chloromethylated poly(a-methylstyrene). Poly(a-methyl styrene)... 

Table VI summarizes the lithographic characteristics of PCMS, CMS, aM-CMS, chlorinated PMS and P-p-MS for polymers with comparable molecular weight and chlorine content. Chlorinated PMS and P-p-MS are as sensitive as PCMS but exhibit better contrast, especially chlorinated P-p-MS. Only the chloromethylated poly-a-methylstyrene shows similar contrast but has much lower sensitivity.

This heterocycle has been appended (76CPB1349) in overall 95% yield based on starting chloromethylated poly(styrene) (192) by utilizing the sequence of reactions shown in Scheme 92. The thiohydarttoin-functional resin (193) was stable in aqueous media below pH 10 and exhibited a high degree of selectivity for Hg2+ ion in competition with Cu2+, Cd2+, Zn2+, Co2+ and Mg + ions. 

The oxazolidine-2,5-dione heterocycle, perhaps better known as the N-carboxyanhydride of an amino acid, has been incorporated employing a modification of chloromethylated poly(styrene) (192) (76USP3985715). The reaction sequence involved utilization of a masked amino acid, ethyl acetamidocyanoacetate (205). The amino acid was liberated in a subsequent hydrolysis/decarboxylation step (Scheme 98). The cyclized, IV-carboxyanhydride-functional resins (206) were reported to be useful in solid phase peptide synthesis and as supports for enzyme immobilization. 

Soluble, amphoteric ion exchange resins have been prepared by reaction of pyridinecarb-oxylic acids, especially 2-pyridinecarboxylic acid (215), with chloromethylated poly(styrene) (192 Scheme 104) (76IZV33). Resin (216) exhibited pronounced selectivity for Cu2+ and Ni2+ ions, and also, at pH 1.65, for the U022 ion. 

Chloromethylated poly(diphenylsiloxane) Negative e-beam, deep UV 193... 

On stirring at room temperature ozonides of terminal alkenes (prepared in dichloromethane at — 70 °C) with a polymer-supported tertiary amine obtained from chloromethylated poly(styrene/divinylbenzene) and piperidine, followed by filtration and concentration under reduced pressure, the products (aldehydes or ketones) can be obtained easily in almost pure form in high yields <2003T493>. However, yields are low for cycloalkenes because apparently they form monomeric and polymeric ozonides. 

Chloromethylated polystyrene and chloromethylated poly(a-methyIstyrene) are negative type resists having high sensitivity and high resolution. In the pulse radiolysis of solid films of this polymer, the absorption spectra of substituted benzyl-type polymer-radical and the charge transfer complex between phenyl rings and chlorine atoms were observed (Fig. 17) [59], The benzyl-type radical may be produced by the dissociative electron attachment to the benzyl part of chloromethylated polystyrene (CMS). 

A logical way of increasing the fraction of transition metal atoms used for active centre formation seems to be the application of the metal compound to a polymer surface [189], The carrier could be identical with, or similar to, the product. This approach is being intensively studied, and various polymers are being tested as carriers, for example poly(styrene-co-divinylbenzene) [190], chloromethylated poly(styrene-co-divinylbenzene) [191], poly-ethylene-0ra/t-poly(4-vinylpyridine) [192], and many others. 

The main reactions taking place when chloromethylated polystyrene (CMS) and chloromethylated poly(diphenylsiloxane) (SNR) are irradiated with high energy electrons or deep UV (KrF excimer laser, 248 nm) radiation have been studied. The results are discussed in terms of short-lived reactive species generated using pulse radiolysis and laser (248 nm) photolysis techniques. 

Figure 3. Transient absorption spectra observed in pulse radiolysis of SNR (partly chloromethylated poly(diphenylsiloxane) solutions in benzene.

Polysiloxanes. The initial reports of the utility of polysiloxanes for lithographic applications spurred several research groups to further investigate this class of materials. The problem of low Tg was addressed by preparing chloromethylated poly(diphenylsiloxane) 16, 17). More recently, poly(sil-sesquioxanes) 18, 19) have been reported as sensitive, negative, e-beam, ion-beam, and UV resists. These soluble, ladder -type polymers prepared by the hydrolysis of substituted chloro- and alkoxysilanes are high-Tg materials (150 °C) with high silicon contents. 

Poly(methyl acetoxy silylene) [poly(MASi)] is also claimed [130] to initiate the polymerization of cyclohexyl methacrylate upon UV irradiation and to crosslink the resulting polymer by air exposure. Finally, the pyridinium salt of partially chloromethylated poly(methyl phenyl silylene) (Q-PMPSi) is reported [131] to initiate the polymerization, in aqueous solution, of hydrophilic vinyl monomers such as methacrylic acid, acrylamide, 2-hydroxyethyl methacrylate and 1 -vinyl-2-pyrrolidone. 

By analogous fashion to imidazoline synthesis (Section 1.11.4.2.2), oxazolines have been introduced by modification of an acrylonitrile-containing polymer with ethanolamine (75JAP(K)75160392). In another modification (Scheme 99), chloromethylated poly(styrene) (192) was treated with a lithiated oxazoline (207) derived from reaction of 2-methyloxazo-line and butyllithium (78MI11106). The oxazoline groups were incorporated, in this study, as intermediates to carboxyl groups. 

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