Polymer Blends Involving Cottonseed Protein and Cottonseed Meal

Polymer blending is a well-established method to generate new materials with modified properties adapted for particular applications.  This method is especially valuable for agro-based materials, where improvements in end-use properties may be desired but chemical modifications may be undesirable.  The resulting blends usually do not contain covalent bonds between the blended components and can more easily satisfy the regulatory and safety requirements during product development. 

We have produced many polymer blends that include cottonseed protein or cottonseed meal.  In this paper, we shall review the use of these blends in adhesive applications.  In particular, cottonseed protein can be blended with soy protein to make products that retain some of the better features of both materials. Cottonseed protein was also blended with polysaccharides.  Neutral polysaccharides (like starch and cellulose) can serve as fillers that lower the cost of the protein, while some anionic polysaccharides (e.g., carboxymethyl cellulose, low-methoxy pectin, and alginate) provide enhanced adhesive strength and water resistance compared with cottonseed protein alone.  The use of nanocellulose, but not cellulose, has also shown improved adhesive performance relative to the protein by itself. Cottonseed meal has also been blended with polycaprolactone (together with a plasticizer, like cottonseed oil), and the blends have shown good melt adhesion properties.  Thus, through careful design and experimentation, it is possible to produce new polyblends from cottonseed protein and cottonseed meal for adhesive applications.