Télomères monofonctionnels du chlorure de vinyle, 4. Synthèse et caractérisation par catalyse rédox

Monofunctional telomers of vinyl chloride ( 1 ) were synthesized by two ways. In the first one, the telomers resulting from the reaction of 1 with carbon tetrachloride were used as telogenic agents to react with allyl acetate leading to a monoadduct. In the second one, monofunctional telogens were used in a redox catalyzed reaction with 1 . Trichloroacetic acid and its esters ( 2b–d ) were applied as telogens. The theoretical maximum yields and the number average degrees of polymerization at these yields were calculated and compared with the experimental results.     

Synthèse de cotélomères photoréticulables, 6. Utilisation de cotélomères biséquencés

Photocrosslinkable block cotelomers were synthesized in three steps. In the first step a monomer M₁ was telomerized with carbon tetrachloride or chloroform, in the second step a monomer M₂ with the resulting macrotelogen, and in the third step the hydroxyl groups were esterified by cinnamic acid or acrylic acid. These reactions were carried out with ethyl acrylate (M₁)/CCl₄ by redox catalysis and subsequently with vinyl acetate (M₂) by free radical initiation, or with vinyl acetate (M₁)/CHCl₃ by free radical initiation and subsequently with isoprene (M₂) by redox catalysis, or with 2-hydroxyethyl acrylate (M₁)/CCl₄ by redox catalysis, and subsequently with isoprene (M₂) by redox catalysis.     

Recherche de télomères à activité pharmacologique potentielle, 2. Télomères de l'acide acrylique et greffage de composés hydroxylés

Several telomers of acrylic acid with carbone tetrachloride were prepared. Their average degree of polymerization, which was between 10 and 50, was determined by several analytical methods (elemental analysis, viscosimetry, and GPC). From the kinetic equations of telomerization a relation between DP _n of these telomers and the experimental conditions is established. Fixation of hydroxylic compounds through direct esterification was studied and it was found that the prepared telomers can be used as hydrosoluble carriers for drugs containing primary alcohol or phenol functions.     

Synthèse de macromères à base de chlorures de vinyle et de vinylidène au moyen de télomères

New macromers 4, 8, and 10, containing ester, alcohol, or acid functions, were prepared starting with vinyl chloride (CV) or vinylidene dichloride (CV₂). The telomer 1, resulting from CV₂ and CCI₄ was telomerized with allyl acetate and the product was transformed into the acrylate 4 by hydrolysis of the reaction product and subsequent esterification. Macromers 8 and 10 were prepared from CV by radical telomerization with thioglycolic acid (7) and 2-mercaptoethanol (9), respectively. Reactive double bonds were introduced into these macromers by reaction with acrylic acid, Vinyl chloroformate, methacryloyl chloride, or 2,3 -epoxypropyle methacrylate, leading to new macromers 12, 13, 14, and 15, respectively.     

Synthèse et étude de copolymères sequencés photochromiques

New photochromic polymers were prepared by deactivating living homo or block copolymers with various 2H-chromene-2-spiro-2′-indolines ( 3a–3d ). Classical anionic polymerization was used throughout this work. By varying the chemical nature of the blocks as well as that of the photochromic units, a series of novel materials was obtained and their structure and behaviour were characterized.     

Synthèse de polysiloxanes téléchéliques, 1. Synthèse de diols et diépoxydes

Telechelic poly(dimethylsiloxane)s ( 4, 5, 6 ) with acetoxy, hydroxyl or 2,3-epoxypropoxy functions as end groups were synthesized. As starting materials chloro-3-acetoxy-[or 3-(2,3)-epoxypropoxy]-propyldimethylsilanes ( 2 and 3 ) were prepared by hydrosilylation of the corresponding allylic derivatives with chlorodimethylsilane, and subsequently condensed with α-hydro-ω-hydroxyoligo- (or poly-) dimethylsiloxanes ( 1b – d ) in the presence of pyridine. The hydroxyl derivatives 5a – d were obtained by hydrolysis of the acetoxy derivatives, and the 3-(2,3-epoxypropoxy)propyl derivatives 6a, b by reaction of the diols with 1-chloro-2,3-epoxypropane.     

Synthèse et caractérisation de polystyrènes siliciés

Poly(p-trimethylsiloxystyrene) (1a) , poly[p-(tert-butyldimethylsiloxy)styrene] (1b) , poly[p-(trimethylsiloxy)-α-methylstyrene] (1c) , poly[p-(tert-butyldimethylsiloxy)-α-methylstyrene) (1d) and poly{p-[2-(tert-butyldimethylsiloxy)ethyl]styrene]} (1e) were prepared by free-radical or cationic polymerization of the corresponding monomers. Poly{[p-[2(trimethylsiloxy)ethyl]styrene]-co-[p-(2-hydroxyethyl)styrene]} (2a) was synthetized by anionic polymerization of the corresponding trimethylsilylated monomer, followed by acid hydrolysis of the resulting polymer. Poly{[p-[2-(trimethylsiloxy)ethyl]styrene]-co-[p-(tert-butoxycarbonyloxy)styrene]} (2b) were prepared by free-radical polymerization of the corresponding monomers.     

Synthèses de diols téléchéliques isomoléculaires par télomérisation

Telechelic diols( 10–13 and 15–18 ) were synthesized by addition of 2-mercaptoethanol( 2 ) and dithiols ( 3 and 4 ) to 9-undecen-1-ol ( 9 ), ω-hydroxyalkyl esters of 10-undenoic acids ( 8a–c ) or N-(2-hydroxyethyl)-10-undecenamide ( 5 ) in the presence of benzoyl peroxide in quantitative yields. The resulting diols have a length in the range of 15 to 50 carbon atoms. They show, however, properties of isomolecular substances.     

Synthèse de polysiloxanes acyloxyméthylés par réaction des acides acétique,benzoïque et méthacrylique,en présence de triéthylamine,sur des polysiloxanes chlorométhylés, 1. Synthèse et identification de trisiloxanes et tétrasiloxanes modèles

3-(Acyloxymethyl)-1,1,1,3,5,5,5-heptamethyltrisiloxanes 7b ₁, 7c ₁, 7d ₁ and 3,5-bis(acyloxymethyl)-1,1,1,3,5,7,7,7-octamethyltetrasiloxanes 7b ₂, 7c ₂, 7d ₂ ( 7b: acetoxymethyl, 7c: benzoyloxymethyl and 7d: methacryloyloxyméthyl derivatives) were synthesized from 3-(chloromethyl)-1,1,1,3,5,5,5-heptamethyltrisiloxane ( 7a ₁) or from 3,5-bis(chloromethyl)-1,1,1,3,5,7,7,7-octamethyltetrasiloxane ( 7a ₂), respectively. Spectroscopic (¹H NMR) and chromatographic (GPC and CG) characteristics of the isolated products were defined in order to standardize the analytical tools used for the study of the carboxylic acid reaction with chloromethylated polysiloxanes in the presence of triethylamine.     

Synthèse de monoalcools et de monoacides chlorofluorés par télomérisation avec des telogènes chlorofluorés

Telomerizations of chlorofluorinated telogens CF₃CCl₃ and \documentclass{article}\pagestyle{empty}\begin{document}$${\rm Cl\rlap{--} (CFCl \hbox{---} CF}_{\rm 2} {\rm \rlap{--} )}_{\rm n} {\rm CCl}_{\rm 3}$$\end{document} (1 ≤ n ≤ 4) with acrylic, allylic, and vinylic monomers were studied. With allyl alcohol and 2-hydroxyethyl acrylate the corresponding fluorinated adducts 1 and 2 were obtained directly. Vinyl and allyl acetates led to the adducts 4a , b and 5a , b , respectively, which could be transformed into the corresponding acetals and alcohols. Telomerizations of methyl acrylate and methacrylate led to the fluorinated adducts 12a and b in the presence of copper chloride as catalyst or also with iron trichloride in the case of methyl methacrylate. By intramolecular elimination the methacrylate adducts were transformed into the lactons 13 and 14 and the acrylate adducts by reduction into the alcohols 1 and 2 . The same reduction of the methacrylate adduct led to the 2,4,4-trichloro-5,5,5-trifluoro-2-methyl-1-pentanol ( 15 ). Independent on the applied catalyst the telomerization of vinylacetic acid led to the monoaddition product, whereas in the case of methacrylic or acrylic acid the formation of monoadducts or higher addition products was found to depend on the catalyst.     

Cinétique de télomérisation, 2. Détermination des lois applicables à la synthèse des télomères à DPn moyens par catalyse rédox

Some theoretical relations concerning the kinetics of redox catalysed telomerization were studied. Assuming that the transfer termination reaction to the metallic cation is the main termination reaction, equations were established giving, as a function of time, monomer and telogen concentrations. Moreover, instantaneous and cumulated number- and weight-average degrees of polymerization could be calculated. As an example the telomerization of ethyl acrylate with carbon tetrachloride as telogen and with ferric chloride/benzoin as catalyst at four concentrations were carried out. The theoretical and the experimental results are in good agreement with the predictions.     

Nouvelle préparation de polychlorophosphazènes linéaires

Polychlorophosphazenes 2 can easily be obtained by thermal condensation of dichlorophosphinoyliminotrichlorophosphorane ( 1 ) under atmospheric pressure at 240–290°C, pure POCl₃ being eliminated. The different stages of the reaction were studied by chemical analysis, ³¹P NMR, IR spectroscopy, and thin layer chromatography. The procedure enables one to obtain polymers of low and high molecular weights. The samples do not contain any cyclic or reticular polymers. Species of low molecular weights can be separated from those with high molecular weights by treatment with heptane. The total yield of phosphorus is 100% with regard to the starting material. Substitution products (Cl by OCH₂CF₃) are obtained which are identical with those obtained with the polychlorophosphazenes prepared via classical methods.     

Application de la réaction de métathèse à la synthèse de prépolymères α,ω-bifonctionnels. 1: Cométathèse entre le cyclooctadiène-1,5 et l'hexène-3 dioate de diméthyle

α,ω-Dimethoxycarbonyl substituted polyenes were synthesized by co-metathesis between 1,5-cyclooctadiene ( 1 ) and dimethyl 3-hexenedioate ( 2 ) by use of the catalytic system WCl₆/Sn(CH₃)₄. The ability of 2 for co-metathesis with 1 was proved by determination of the distribution of low molecular weight products in terms of reaction time and 2/1 mole ratio. For these studies, high values of 2/1 ratios (0,5–4) were chosen in order to obtain lowest molecular weight co-metathesis products ( 3b–3e ). Metathesis involved preferentially the double bonds in the neighbourhood of the ester groups. At lower values of the 2/1 ratio (0,012–0,061) α,ω-difunctional prepolymers ( 3i ) were synthesized.     

Oligomères amphiphiles obtenus par voie radicalaire, 1. Synthèse et caractérisation d'oligomères de l'acide acrylique à extrémité dodécylthio

Oligomeric emulsifiers were prepared by the technique described by Roe, with special care of composition and molecular weight. Acrylic acid was polymerized in 2-propanol with lauroyl peroxide as initiator in the presence (at various ratios) of 1-dodecanethiol ( 8 ) as transfer agent to control the chain length. A good agreement was found between the various methods used for kinetic determination and oligomer characterization (¹H NMR, sulfur analysis, vapor pressure osmometry, acidimetry, GPC). Values of k_pk_t^-1/2, transfer constants for thiol 8 and solvent, nature of chain ends, polydispersity, and molecular weight were determined. Polymer fractionation was successfully performed using different solvents for recovery.     

Télomères monofonctionnels du chlorure de vinyle, 3. Cinétique par catalyse rédox

A kinetic study of the redox telomerization of vinyl chloride with carbon tetrachloride was carried out. Transfer constants of PVC to the metallic ion (C_Feⁿ), initiation rate (k_i), and functionnality of the resulting telomers were measured. Instantaneous and cumulated polymerization degrees, (DP_n )_i and (DP_n )_cum were determined with the help of a theoretical study. These constants provide a rigorous control of the telomerization of vinyl chloride with RCCl₃, (R containing an alcohol or ester group).     

Modification des polyméres de vinyl-4 benzophénones méthoxylées et copolymérisation des monomères avec le styréne

The polymerization of acrylonitrile, methyl methacrylate and styrene initiated by copper(II) chelates was studied in the prescence of carbon tetrachloride. A polymeric amine and a monomeric diamine, that is, polyvinylamine and 1,3-diaminopropane, were chosen as ligands. The activity of the polymeric chelate was found to be specific and higher than that of the 1,3-diaminopropane chelate. It was compared with that of the 1,3-diaminopropane chelate, by changing pH values of the system and the reaction temperature. Plots of conversion against pH afforded a peak at pH 8, and trends of increasing of conversion were observed above pH 10. The apparent activation energy of the polymerization initiated by the polymeric chelate was higher than the apparent activation energy of the polymerization initiated by the 1,3-diaminopropane chelate. The fact was attributed to the difference of their chemical structures.     

Modification au deuxième degré de polymères époxydés, 3. Fixation de l'acide α-naphtylacétique sur polyisoprène-1,4 époxydé. Etude sur molécule modèle

The reaction of α-naphthylacetic acid ( 1 ) (a plant growth stimulator) with 4,5-epoxy-4-methyloctane ( 2 ) which reproduces the constitutional unit of epoxidized 1,4-polyisoprene was studied. The rate of addition of the acid to the oxirane ring of 2 in chloroform with the tetramethylammonium salt of the acid 1 as catalyst increases with temperature, time, and concentration of the reagents.     

Etude de la dégradation thermique de deux copolymères réalisés entre l'acrylonitrile ou le méthacrylonitrile et l'α-acétoxyacrylate de méthyle. Analyse thermogravimétrique et chromatographique en phase gazeuse couplée à la spectrométrie de masse

The thermal degradation behaviour of two copolymers poly(acrylonitrile-co-methyl α-acetoxyacrylate) and poly(methacrylonitrile-co-methyl α-acetoxyacrylate) was studied by means of dynamic and isothermal thermogravimetry in the range 246–302°C and gas chromatography/mass spectrometry analysis. The main volatil products are acetic acid and methyl acetate and methanol in minor amounts. There is no monomer from the first copolymer. The global reaction order is zero over a wide range of conversion (α = 0,1 – 0,6), then it is one for α > 0,7, with activation energies of 160,5 and 142,9 kJ ˙ mol^?1, respectively. Some amount of comonomers was found in addition in the case of the second copolymer. The kinetic law may be written as: where A and C are constants for every temperature. The global activation energy was found to be 127,0 kJ ˙ mol^?1. A kinetic model of a one order reaction with a partial auto catalytic character allows a very good fit of the experimental data with the theoretical curves over a wide range of conversion (α = 0,1–0,8).     

Télomères et cotéloméres d'intérêt biologique et biomédical, 7. Synthèse, évaluations physico-chimiques et biologiques de télomères amphiphiles de type acryloylamino-acide

New ionic telomeric surfactants derived from acryloylamino acids were synthesized and their tensioactive properties compared to those of non-ionic analogs previously reported. We also compared their anti HIV behavior with that of other polymeric polyanionic derivatives. Acryloyl monomers of various amino acids such as glycine, alanine, aspartic, glutamic and γ-aminobutyric acid were prepared and telomerized in the presence of various alkanes or perfluoroalkanethiols as chain transfer reagents. For a given amino acid, the critical micellar concentration (CMC) was shown to depend upon the nature and the length of the hydrophobic tail and not the size of the hydrophilic head, i.e., the number average degree of polymerization (DP _n). None of the telomeric polyanionic derivatives reported herein induced HIV inhibition.     

Synthèse et application de diols isomolécularies aux résines polyuréthannes

Different methods of preparation of monodisperse diols were reviewed and a new synthesis of perfectly monodisperse macrodiol 5 is described, obtained by radical telomerization of monoester 3 b (prepared by esterification of 10-undecenoic acid ( 3 a ) with 1,6-hexanediol) with dithiol 4 . Macrodiol 5 was used to obtain prepolymers by reaction with aromatic or aliphatic diisocyanates ( 6 and 7 ). Finally, these prepolymers were extended by 1,4-butanediol and led to polyurethanes. All the above products were analyzed by GPC, ¹H NMR, and the resulting polyurethanes were tested mechanically. The study shows that monodisperse diols lead to better mechanical properties of the polyurethane than those obtained from polydisperse diols with equal molecular weight.