Abstract
The replacement of glass fibers polymer composites with those containing polymers and cellulose fibers, friendly for environment and human health has gained a special importance in recent years. The paper presents some mechanical and thermal characteristics of composites of neat polypropylene and jute fibers from technological wastes, treated and untreated. The use of waste fibers in polypropylene led to a significant increase of the elastic modulus and tensile strength which highlights the reinforcing effect of the waste fibers, the effect being more important in case of jute fibers treated with aminosilane. Keywords: polypropylene, composites, jute, mechanical properties