A method for producing thermosetting phenolic resins includes the step of reacting a polycondensable phenolic compound with 5-hydroxymethylfurfural (HMF) under conditions leading to the formation of polycondensation products. The HMF includes at least one HMF oligomer, and the reaction step is carried out at pH values greater than 7 for more than 60 minutes. Further, thermosetting phenolic resins may be used for producing a wood composite material.

A method for producing thermosetting phenolic resins includes the step of reacting a polycondensable phenolic compound with 5-hydroxymethylfurfural (HMF) under conditions leading to the formation of polycondensation products. The HMF includes at least one HMF oligomer, and the reaction step is carried out at pH values greater than 7 for more than 60 minutes. Further, thermosetting phenolic resins may be used for producing a wood composite material.

The present disclosure provides a functionalized phthalonitrile monomer derived from a polyhydric phenol comprising at least one furan group or thiophene group and 4-nitrophthalonitrile. The functionalized phthalonitrile monomer may be used in various thermosetting compositions which can be cured to form thermoset polymers having excellent thermal and mechanical properties, such as high thermal stability, heat resistance, high char yield, and enhanced structural rigidity.

The present disclosure provides a functionalized phthalonitrile monomer derived from a polyhydric phenol comprising at least one furan group or thiophene group and 4-nitrophthalonitrile. The functionalized phthalonitrile monomer may be used in various thermosetting compositions which can be cured to form thermoset polymers having excellent thermal and mechanical properties, such as high thermal stability, heat resistance, high char yield, and enhanced structural rigidity.

The present invention provides: an epoxy resin which has a high elastic modulus and excellent low water absorption; and a curable resin composition which contains the epoxy resin. The present invention specifically provides an epoxy resin represented by formula (1) (In formula (1), a plurality of R.sub.1 moieties each independently represent a hydrocarbon group having 1 to 10 carbon atoms. R.sub.2 moiety represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. n is the average value of repetitions, and is a real number satisfying 1<n<15.)

##STR00001##

A curable resin composition has high biomass content and is exemplary in high heat resistance and low dielectric properties and a cured product of the curable resin composition. The curable resin composition includes an epoxy resin represented by the following formula (1) and an acid anhydride curing agent including a biomass-derived compound. (In formula (1), n is an average value of the number of repetitions and represents a real number where 1<n<15.)

##STR00001##

The present invention provides: an epoxy resin which has a high elastic modulus and excellent low water absorption; and a curable resin composition which contains the epoxy resin. The present invention specifically provides an epoxy resin represented by formula (1) (In formula (1), a plurality of R.sub.1 moieties each independently represent a hydrocarbon group having 1 to 10 carbon atoms. R.sub.2 moiety represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. n is the average value of repetitions, and is a real number satisfying 1<n<15.)

##STR00001##