Abstract: 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 biodegradability to acceptable byproducts. The cyclic carbonate (CC) from the monoketal diol of pentaerythritol polymerized in CHCl3 at 60° C. with Et2Zn catalyst in CHCl3 at 60° C. in 4 hours to a quantitative yield of high molecular weight, crystalline polymer (PCC), melt peak 199° C. and Tg of 99° 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 Mw=3.1×104. HPC degrades completely in vitro in <16 hours in PBS-1X buffer (Ph 7.4, 37° C.) to pentaerythritol and presumably CO2. This rapid degradation rate is decreased with random copolymers of HPC with CC, &egr;-caprolactone, or L-lactide.

Abstract: High molecular weight (Mw>25,000, preferably >50,000; n.sub.inh up to 3) ear atactic poly (3-hydroxyoxetane) (PHO) are made by polymerizing the trimethylsilyl ether of 3-hydroxyoxetane with a coordination catalyst, or preferably with a cationic catalyst such as i-Bu.sub.3 Al-0.7 H.sub.2 O, followed by hydrolysis. The new polymer is atactic, highly crystalline, has a melting point of 155.degree. C., is devoid of measurable end groups, has a two-peak .sup.13 C-NMR, and can be readily compression molded at 200.degree. C. to a film which can be drawn at room temperature to give enhanced strength.Isotactic high molecular weight PHO (mp=223.degree. C.; .DELTA.H.sub.f =25.6 cal/g) and branched high molecular weight PHO are also prepared.

Abstract: Poly[3,3-bis(hydroxymethyl)oxetane] ("PBHMO") is prepared in high molecular weight (n.sub.inh to 5.2) by polymerizing the trimethylsilylether of 3,3-bis(hydroxymethyl)oxetane with i-Bu.sub.3 Al-0.7 H.sub.2 O cationic catalyst at low temperature, followed by hydrolysis. PBHMO is crystalline, high melting (about 314.degree. C.), highly insoluble and useful in the production of films and fibers. Poly[3-methyl-3-(hydromethyl)oxetane] ("PMHMO") and poly[3-ethyl-3-(hydroxymethyl)oxetane] ("PEHMO") are also prepared in high molecular weight (n.sub.inh up to 3.8) by the same procedures. Copolymers of BHMO, MHMO, and EHMO with each other or containing up to about 50% of other oxethanes, oxiranes and tetrahydrofurans; derivatives and alloys from these polymers and copolymers; and methods of preparing the polymers, copolymers, alloys and derivatives into useful films, fibers and articles is described.

Abstract: An improved titanium trichloride catalyst component is prepared by treating a crude titanium trichloride composition with two different electron donor compounds via successive treatment with first one of the donor compounds and then with the other. The treated composition provides greater stereospecificity in the polymerization and copolymerization of propylene.

Abstract: An improved process for the polymerization of epoxides with an organoaluminum catalyst is described. Improvements in conversion, yield and reaction rate are realized by contacting the epoxide at a temperature below 0.degree. C. with at least a catalytic amount of the organoaluminum compound in the presence of at least 0.1 mole, per mole of aluminum, of a perhalogenated aliphatic monoketone which is preferably hexafluoroacetone.