Random block copolymers composed of poly(oxytetramethylene) glycol(PTMG) and poly(butylene terephthalate) (PBT) were prepared and its melt properties were studied. To lower their melt viscosities, lubricants and/or low mol. wt. PBT-PTMG block copolymers were compounded. To increase their initial modulus, one component of their segments, PBT, was blended.
Lubricants of amide type turned out to be the most effective among various types of lubricants. Low mol.wt. PBT-PTMG block copolymers also exhibited lubricating effect. Blending of PBT had an effect on increasing the initial modulus, with moderate decreasing tensile strength and elongation.
