Hydroxypolycarbonates (HPC) offer to the biomedical area hydroxyl functional polymers not now readily available to bind drugs, proteins, or carbohydrate polymers chemically or via hydrogen bonding to facilitate drug delivery and utility with subsequent biodegradibility to acceptable byproducts. The cyclic carbonate (CC) from the monoketal diol of pentaerythritol polymerized in CHCl3 at 60 degrees C with Et2Zn catalyst in CHCl3 at 60 degrees C in 4 h to a quantitative yield of high molecular weight, crystalline polymer (PCC), melt peak 199 degrees C and T-g of 99 degrees C. PCC is readily hydrolyzed with 80% acetic acid to the water-insoluble but water-swollen HPC, poly[5,5-bis(hydroxymethyl)-1,3-dioxan-2-one], with M-w = 3.1 x 10(4). HPC degrades completely in vitro in <16 h in PBS-1X buffer (pH 7.4, 37 degrees C) to pentaerythritol and presumably CO2. This rapid degradation rate is decreased with random copolymers of HPC with CC, epsilon-caprolactone, or L-lactide. HPC and PCC may have important biomaterial applications as is and as the copolymers noted above or with ethylene oxide or other desirable comonomers. PCC and CC copolymers have properties attractive to the biomedical area as is or by conversion to the HPC product provided by hydrolysis or by in vivo enzymatic attack.