New aliphatic polycarbonates derived from trimethylene carbonate (1) (TMC, 1,3-dioxan-2-one), have been prepared by ring opening polymerization. The synthesis is achieved by using new aluminum alkoxide initiators which allow for the incorporation of controlled functionality in the resulting polymer. The synthesis of poly(TMC) with nitrophenyl end groups was achieved by using initiators of the form, Al(Et)(3-x)(OR)(x); where x = 1-2, R = -(CH2)(2)PhNO2. The end groups could be reduced to give the corresponding aminophenyl end-capped poly(TMC). In these polymerizations, molecular weight is proportional to the monomer/intiator ratio, with each polymer chain containing one nitrophenyl or aminophenyl functionality.