Propargyl monomers

The liquid study of propargylic monomers during heat treatment has shown the formation of secondary phenolic products in the reaction mixture and solid-state CPMAS NMR has confirmed the structure of the final polymer. ... 

The preparation of several propargyl monomers and diacetylene polymers. and their initial characterization as radiation cured coatings for corrosion protection is discussed in the present report. 

The propargyl monomers are available in a pure state from a one-step, easy preparation which proceeds in quantitative yield from industrially produced inexpensive starting raw materials Bisphenol A (62 cents per pound) and propargyl chloride ( 5.00 per pound). 

We have prepared several different propargyl monomers according to the procedure described in the experimental part for dipropargyl ether of Bisphenol A, with a general formula ... 

The other propargyl monomers including the monofunctional propargyl derivatives of para- and meth-cresol have been prepared in a similar manner. Their purity and structure has been proven by GC, m.p., infrared, H- and C-NMR spectroscopy. 

The propargyl monomers are easily prepared in almost quantitative yield by reaction of propargyl chloride with bisphenols or polyphenols in the presence of aqueous sodium hydroxide. The monomers can be purified by recrystallization when they are crystalline. In addition the propargyl monomers were reported to have a lower toxicity than the epoxies and isocyanates [33]. 

A template mechanism was also proposed for spontaneous polymerization of propargyl chloride in the presence of poly(4-vinylpyridine). The reaction consists of partial (6-8%) alkylation of P4VPy by propargyl chloride which leads to stable complex P4VPy with monomer and then to polymerization. The product obtained contains a conjugated bond system formed by opening triple bonds in the monomer according to reaction ... 

Rh complexes are examples of the most effective catalysts for the polymerization of monosubstituted acetylenes, whose mechanism is proposed as insertion type. Since Rh catalysts and their active species for polymerization have tolerance toward polar functional groups, they can widely be applied to the polymerization of both non-polar and polar monomers such as phenylacetylenes, propiolic acid esters, A-propargyl amides, and other acetylenic compounds involving amino, hydroxy, azo, radical groups (see Table 3). It should be noted that, in the case of phenylacetylene as monomer, Rh catalysts generally achieve quantitative yield of the polymer and almost perfect stereoregularity of the polymer main chain (m-transoidal). Some of Rh catalysts can achieve living polymerization of certain acetylenic monomers. The only one defect of Rh catalysts is that they are usually inapplicable to the polymerization of disubstituted acetylenes. Only one exception has been reported which is described below. 

Propargyl alcohol HC = 0—CHgOH ako gives an infrared spectrum indicative of only a monomer dimer equilibrium, although since here there can be no steric hindrance there is no obvious reason why this should be the case. Its nuclear resonance shift with dilution is more akin to the kind shown by polymer-forming alcohols, and the anomaly... 

Ftg. 7. The Lr, spectrum of propargyl alcohol showing (two right-hand peaks) that only monomer-dimer equilibrium appears to be involved... 

Bis(trifluoromethyl)-4,5-difluoro-l,3-dioxole represents the monomer of a new family of amorphous fluoropoiymers (Teflon AF, DuPont) with unusual properties [89JFC(45)100]. Novel fluorinated 2,2-bis(triflu-oromethyl)dioxolanes containing alkyne groups have been synthesized from hexafluoroacetone and propargylic alcohol, bromomethyloxirane, or 1,2-bis(bromomethyl)oxirane [90MI1 91JFC(52)I59] (Scheme 95). 

The monomers were propargyl a-substituted (methyl, pentyl, methyl phenyl, cyclohexyl) propargyl ethers. Polymerization was carried out with various transition metal catalysts, as shown in Scheme 6. The... 

All of these methods are suitable for an industrial scale-up and propargyl terminated monomers might be available at a potentially low price. 

Lower molecular weight polymers with lower viscosity have been prepared by introducing mono-functional monomers (for instance, propargyl ether of p-cresol) into the polymerization feed which terminates the polymerization growth. The molecular weight of these polymers as well as their viscosity has been varied with the amount of the mono-functional monomer. These polymers or oligomers have lower viscosity and they may be more suitable for coatings applications. 

Monomer Preparation. Preparation of dipropargyl ether of bisphenol A a solution of 228.29 g. (1 mole) of bis-phenol A in two liters of acetone was reacted with 285.53 g (2.4 moles) of propargyl bromide in the presence of... 

PREPARATION OF POLYMERS FROM PROPARGYL-TERMINATED MONOMERS... 

Preparation of Polymers from Propargyl-Terminated Monomers... 

If desired, the propargyl-terminated monomers can be B-staged without a catalyst at 185°C for 16-25 hr. This prepolymerization leads to the formation of liquid oligomers below the gel point. It also helps to eliminate shrinkage during the final curing stage, which takes place at 205-210°C for 4 hr without a catalyst allowed by 260°C for 6 hr to improve physiomechanical properties. 

Bisphenol A propargyl ethers rearrange to chromenes (I) on heating in the range from 150°-220°C [35]. This is normally carried out in a solvent such as diethylbenzene (Dowtherm J). These chromene-propargyl ether monomer mixtures are of the structure... 

Gas chromatographic research with plasma-coated silica gel adsorbent and an ultrafiltration test of organic solutes having different molecular sizes have revealed that the polymer appears to have micropores of 2-4 nm in diameter. Control of the dissolution rate of pharmaceuticals by dianging the polymer film thickness was also attempted [72], It was found that propargyl alcohol is a very promising monomer and a few applications of this hydrophilic plasma polymer have been reported [72]. 

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