Formaldehyde-free melamine carbohydrate binders for improved fire-resistant fibrous materials

A method of making a fiber-reinforced composite, the method comprising:

• providing a plurality of fibers;
• contacting the plurality of fibers with a formaldehyde-free binder composition to make a fiber-binder amalgam, wherein the formaldehyde-free binder composition comprises:
• melamine,
• a reducing sugar,
• a non-carbohydrate aldehyde or ketone selected from the group consisting of glyoxal, acetaldehyde, butyraldehyde, glutaric dialdehyde, acetone, methyl ethyl ketone, and pentanedione, or
• comprises a compound having the formula:
• where R1 and R2 are independently selected from hydrogen, an alkyl group, an aromatic group, an alcohol group, an aldehyde group, a ketone group, a carboxylic acid group, and an alkoxy group, and
• a curing catalyst;
• and
• heating the fiber-binder amalgam to a temperature of 100° C. to 250° C. to form the fiber-reinforced composite, wherein:
• the binder composition forms (i) a reaction product of only the melamine and the non-carbohydrate aldehyde or ketone that reacts with (ii) the reducing sugar to make a crosslinked polymeric cured binder.