Effect of Compatibilizers on Interfacial Strength in Microdenier Bicomponent Fibers

Interfacial strength in bicomponent fibers remains a significant challenge jeopardizing durable adhesion and delamination prevention. An integrated experimental-numerical approach is developed here to engineer strengthened interfaces by means of compatibilizers and quantify their effect. Measurements of interfacial adhesion energy indicate that chemically dissimilar polyamide/polyolefin pairs reveal substantially lower values than those of polypropylene/polyethylene (PP/PE). In the case of PP/PE interfaces, compatibilizers markedly increase the adhesion energy while leaving bulk mechanical properties essentially unaffected. Numerical analysis identified that the area ratio and the mismatch in the thermal expansion are the dominant factors determining the interfacial stresses. Elucidation of additional material pairs and geometries reveals results ranging from stable compressive interfaces to disjoining high-stress regions that promote interfacial delamination. Overall, the results support the applicability of the present approach to provide quantitative guidance for designing bicomponent fibers toward either durable interfaces or delaminated interfaces by design.