ABSTRACTRenewable resource‐based polyesters, poly(trimethylene malonate) (PTM) and poly(trimethylene itaconate) (PTI), were synthesized from 1,3‐propanediol, malonic acid, and itaconic acid via melt polycondensation using green chemistry principles. Aluminum chloride, a Lewis acid, was used as the catalyst at different reaction temperatures. Chemical structure of PTM and PTI with low dispersities showed the presence of ester and ether bonds. A bimodal molecular weight distribution exists, with the high molecular weight fraction ranging from 22 to 38 kDa while the low molecular weight fraction did not exceed 2.5 kDa. Thermal analysis of PTM showed a Tg ranging between –66 and –41 °C. PTM could be used as a plasticizer for other degradable bioplastics, sensor applications, and drug delivery. PTI, a semi‐crystalline thermoset polymer, may be used for production of packaging material, disposable utensils, tableware, indoor furnishings, and more importantly, as a degradable biomaterial for biomedical applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43917.