Influence of fiber surface treatment on the creep behavior of jute fiber-reinforced polypropylene

Improvements in the characteristic properties of jute-polypropylene composites were obtained with the application of MAH grafted PP copolymers as a coupling agent to the fiber. SEM investigations demonstrated that fiber pull-out is reduced after the modification with the coupling agent. This improved fiber-matrix adhesion further leads to a lower creep strain in the outer fibers. This was demonstrated for composites with two different fiber contents. Up to applied stresses of 5.1 N/mm(2), the creep behavior for the composites with unmodified, as well as for those with MAH-PP modified, fibers obeys the creep law according to Abbott. The experimental data of creep tests at higher applied stresses were fitted more successfully by using the creep law according to Findley. The creep kinetic coefficient according to Abbott was dependent on the applied stress for both types of composites and for both fiber contents.