HDPE ROSIN BLENDS - I-MORPHOLOGY, MECHANICAL AND RHEOLOGICAL PROPERTIES/

Melting mixtures of high density polyethylene (HDPE) and glycerol este r of hydrogenated rosin (ester gum) were prepared under select conditi ons using up to 50% of rosin. All blends showed phase separation. The size of rosin domains varied with the content of low molecular weight constituent. The 50/50 blend showed the highest dispersion and the pre sence of micro and macro rosin domains. Up to 20% rosin a slight decre ase of Young's modulus was noticed while above this rosin content a sl ight increase occurred. The stress and elongation dropped markedly abo ve 10% of rosin. The hardness of blends showed the same behavior as th e elastic modulus. The melt now index increased exponentially with the rosin content while processability has improved.