Morphology and improved impact strength of cellulose acetate butyrate blended with polyethylene copolymer

Abstract

Incompatible blends of cellulose acetate butyrate (CAB) and copolymer of ethylene, acrylic ester, and maleic anhydride (PE-Acr-MA) with a component ratio 70/30 vol% were prepared by melt extrusion at the rates of 150 and 500 rpm. The goal was to modify weak impact properties of CAB. We showed that at a speed of 500 rpm, both small individual (0.9 µm in diameter) and large coalesced (2.3 µm in diameter) particles of the PE-Acr-MA phase were formed; the impact strength of the blend increased in 6.5 times as compared with that of pure CAB. However, at a melt mixing rate of 150 rpm, the size of the individual PE-Acr-MA particles decreased in 3.8 times, whereas that of the coalesced particles diminished by 6.6 times; the impact strength of the blend increased in about 40 times as compared with that of pure CAB and reached the values around and higher than 70 kJ/m2. The effect of the screw rotating speed on viscoelastic properties of each component and their viscosity ratio was analyzed and shown to control blend morphology and mechanical properties.

Keywords

• Polymer blends and alloys
• cellulose acetate butyrate
• polyethylene copolymer
• blend morphology
• impact properties