Fibrillar crystallization of polymers in the presence of fillers provides both mechanical and thermal property improvement in the composite. This research outlines studies of ultrahigh molecular weight polyethylene (UHMWPE) crystallized in the presence of boron nitride nano-platelets (BNnP) under shear. æThis process yields fibers consisting of hybrid UHMWPE/BNnP fibrillar crystals. æThe overall composite fiber has BNnP loading ranging from 11 to 33 wt%. ææBNnP is injected at the onset of PE crystallization and this promotes hybrid crystallization and interfacial interactions between the BNnP and UHMWPE. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) show that the crystal structure of the UHMWPE is altered in the presence of the BNnP. æThis results in improved mechanical performance. The resultant effects of temperature, polymer concentration and drawing on crystallinity and mechanical properties of the BNnP-UHMWPE composite will be discussed in this poster.