Method for producing an ablative resin

A method for producing a phenolic resin comprising the following steps:

• reduction of a compound of formula A in order to obtain a hydroxybenzyl alcohol of formula B, formulae A and B being the following:
• wherein:
• n1 is an integer between 0 and 4 and when m is greater than or equal to 2, the substituents R1 are identical or different,
• R1 is chosen from:
• —OH, —COOH, —CHO, the groups —O-Alk wherein Alk denotes a substituted or unsubstituted alkyl chain of 1 to 4 carbon atoms, saturated or unsaturated, substituted or unsubstituted hydrocarbon-based chains comprising between 1 and 20 carbon atoms, interrupted or not with one or more heteroatoms, and having or not having one or more carbonyl or carboxylic acid functions, substituted or unsubstituted, monocyclic or polycyclic, saturated, unsaturated or aromatic carbocyclic or heterocyclic groups having or not having one or more carbonyl or carboxylic acid functions, and substituted or unsubstituted aryl groups having or not having one or more carbonyl or carboxylic acid functions, and
• R2 denotes —H or —OH, and
• polymerization reaction between the hydroxybenzyl alcohol and aldehyde compound in order to obtain the phenolic resin, the aldehyde compound having one of the following two formulae C or D
• in formulae C and D, n3 is an integer between 0 and 4 and when n3 is greater than or equal to 2, the substituents R3 are identical or different, n4 is an integer between 0 and 5 and when n4 is greater than or equal to 2, the substituents R4 are identical or different and n5 is an integer between 1 and 6, the substituents R3 and R4 being chosen independently from one another from:
• —OH, —COOH, —CHO, the groups —O-Alk wherein Alk denotes a substituted or unsubstituted alkyl chain of 1 to 4 carbon atoms, saturated or unsaturated, substituted or unsubstituted hydrocarbon-based chains comprising between 1 and 20 carbon atoms, interrupted or not with one or more heteroatoms, and having or not having one or more carbonyl or carboxylic acid functions, substituted or unsubstituted, monocyclic or polycyclic, saturated, unsaturated or aromatic carbocyclic or heterocyclic groups having or not having one or more carbonyl or carboxylic acid functions, and substituted or unsubstituted aryl groups having or not having one or more carbonyl or carboxylic acid functions,
• R4 also denoting or not denoting a radical of formula C1 in formula C above or a radical of formula D1 in formula D above and R3 also denoting or not denoting a radical of formula C2 in formula C above, formulae C1, C2 and D1 being the following:

A method for producing a propulsion nozzle, wherein the nozzle is produced from a phenolic resin obtained by carrying out a production method comprising the following steps:

• a) reduction of a compound of formula A in order to obtain a hydroxybenzyl alcohol of formula B, formulae A and B being the following:
• wherein:
• n1 is an integer between 0 and 4 and when n1 is greater than or equal to 2, the substituents R1 are identical or different,
• R1 is chosen from:
• —OH, —COOH, —CHO, the groups —O-Alk wherein Alk denotes a substituted or unsubstituted alkyl chain of 1 to 4 carbon atoms, saturated or unsaturated, substituted or unsubstituted hydrocarbon-based chains comprising between 1 and 20 carbon atoms, interrupted or not with one or more heteroatoms, and having or not having one or more carbonyl or carboxylic acid functions, substituted or unsubstituted, monocyclic or polycyclic, saturated, unsaturated or aromatic carbocyclic or heterocyclic groups having or not having one or more carbonyl or carboxylic acid functions, and substituted or unsubstituted aryl groups having or not having one or more carbonyl or carboxylic acid functions, and
• R2 denotes —H or —OH, and
• b) polymerization reaction using the hydroxybenzyl alcohol of formula B obtained during step a) in order to obtain the phenolic resin,
• wherein there is, during step b), reaction of the hydroxybenzyl alcohol of formula B with a phenolic compound other than said hydroxybenzyl alcohol,
• the phenolic compound which reacts with the hydroxybenzyl alcohol during step b) being chosen from:
• phenol, pyrocatechol, hydroquinone, phloroglucinol, pyrogallol, guaiacol, syringol, bisphenol A, bis-phenol S, para-hydroxybenzaldehyde, vanillin, syringaldehyde, dehydrodivanillin, vanillyl alcohol, syringyl alcohol, para-coumaryl alcohol, coniferyl alcohol, sinapyl alcohol, ferulic acid, sinapylic acid, para-hydroxybenzoic acid, vanillic acid, syringic acid, gallic acid, para-coumaric acid, eugenol, isoeugenol, cardanols, cardols, anacardic acids, catechin, umbelliferone, juglone, trans-resveratrol, kaempferol, daidzein, delphinidol, enterodiol, lignins, procyanidins, gallotanins, condensed tannins, and resol and novolac resins.