Utilization of Pulverized Cross-linked Polyethylene Foam as Effective Filler for Linear Low-Density Polyethylene

Cross-linked polyethylene foam (XPEF) is widely used in packaging and insulation applications. Since cross-linked polymer cannot be reprocessed similar to thermoplastics, utilization of these thermoset materials is an environmentally challenging problem. Due to thermoset nature, it can be used as filler or reinforcement in other base materials. Since cross-linked polyethylene will have a better compatibility with polyolefin matrix, using waste cross-linked polyethylene as filler in polyolefin material will be an attractive solution First, XPEF was crushed to particles with mesh size of about seven and was used as filler in linear low density polyethylene (LLDPE) having 6.5 melt flow index. Concentration of waste cross-linked foam powder was varied up to 40 phr in LLDPE matrix. Tensile, flexural, impact, vicat softening temperature, heat distortion temperature, scanning electron microscopy, and rheological properties were analyzed for the prepared compositions. Impact strength of LLDPE is found to have increased by 380% on 40 phr addition of the foam powder in LLDPE matrix. Overall changes in mechanical properties are similar to cross-linked polyethylene. From scanning electron microscope images, it became evident that the waste cross-linked foam powder acted as a point of entanglement with different chains of LLDPE, giving physical cross-linking.