Bio-based binders for insulation and non-woven mats
An aqueous binder composition is provided that includes a carbohydrate and a crosslinking agent. In exemplary embodiments, the carbohydrate-based binder composition may also include a catalyst, a coupling agent, a process aid, a crosslinking density enhancer, an extender, a moisture resistant agent, a dedusting oil, a colorant, a corrosion inhibitor, a surfactant, a pH adjuster, and combinations thereof. The carbohydrate may be natural in origin and derived from renewable resources. Additionally, the carbohydrate polymer may have a dextrose equivalent (DE) number from 2 to 20. In at least one exemplary embodiment, the carbohydrate is a water-soluble polysaccharide such as dextrin or maltodextrin and the crosslinking agent is citric acid. Advantageously, the carbohydrates have a low viscosity and cure at moderate temperatures. The environmentally friendly, formaldehyde-free binder may be used in the formation of insulation materials and non-woven chopped strand mats. A method of making fibrous insulation products is also provided.
1. A binder composition for use in the formation of fiberglass insulation and non-woven mats, the binder composition comprising:
from 40% to 95% by weight of maltodextrin having a dextrose equivalent number from 2 to 14, and a number average molecular weight of from 1,000 to 8,000; and
from 5% to 40% by weight of a single crosslinking agent, the single crosslinking agent selected from citric acid, salts of citric acid, polyacrylic acid, and salts of polyacrylic acid;
wherein the binder composition is devoid of additional crosslinking agents,
wherein the weight percentages are based upon the weight of total solids of the binder composition.
2. The binder composition of claim 1 , wherein the single crosslinking agent has a number average molecular weight of from 90 g/mol to 10,000 g/mol.
3. The binder composition of claim 1 , wherein the binder composition further comprises a sodium hypophosphite catalyst.
4. The binder composition of claim 1 , wherein the binder composition further comprises at least one of a nonionic surfactant and a vegetable oil.
5. The binder composition of claim 1 , wherein the binder composition further comprises a silane coupling agent.
6. The binder composition of claim 1 , wherein the binder composition further comprises up to 10 wt. % of a biocide, based upon the weight of total solids of the binder composition.
7. The binder composition of claim 1 , wherein the binder composition further comprises at least one of glycerol, 1,2,4-butanetriol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, and polyethylene glycol.
8. The binder composition of claim 1 , wherein the binder composition further comprises a dye additive.
9. A non-woven mat comprising:
a plurality of glass fibers in the form of a mat having a first major surface and a second major surface; and
the binder composition of claim 1 at least partially coating the first major surface of the mat.
10. The non-woven mat of claim 9 , wherein the binder composition in a cured state comprises at least one polyester.
11. The binder composition of claim 1 , wherein the binder composition has a pH of from 1 to 2.5.