Blends comprising 65-95 wt % poly(trimethylene terephthalate-co-sebacate), 5 to 35 wt % polylactic acid and a chain extender are provided that exhibit greatly increased melt strength compared to that of poly(trimethylene terephthalate-co-sebacate) alone. Such improvements allow these compositions to be processed readily by melt-blowing, which is useful for packaging and for preparing items such as biodegradable garbage bags.