Polycaprolactone based biodegradable polyurethanes

Abstract

Two series of segmented polyurethanes were prepared with systematic variation in soft and hard segment length. The soft segment was constituted by polycaprolactone (PCL) blocks of molecular masses 530 or 2000 and the hard segment (HS) by urethane blocks, in a concentration that varied from 12% to 44% in weight of the whole polyurethane. Morphological analyses indicated that the amount of crystallinity of copolymers was strongly dependent on the PCL molar mass and hard segment content. The copolymers with longer PCL soft segments (Mn=2000) were semicrystalline, but those with shorter PCL segment (Mn=530) were unable to crystallize. The primary factor affectingthe biodegradability of copolymers as evaluated by Sturm tests was the extent of the phase separation, and that the segmental blending of the less biodegradable polyurethane (HS) blocks with PCL in the amorphous phase had a critical unfavorable consequence, which may be attributed to the size of the accessible area by microorganisms.

Controlled Release of Model Drug from Biodegradable Segmented Polyurethane Ureas: Morphological and Structural Features

“…PCL(530)(50)BDA rapidly degraded into completely water-soluble products within 3 hrs, while the degradation times of the PCL(1250)(70)BDA and PCL(2000)(80)-BDA varied from 1-4 days. The slower degradation rate of PCL(1250)(70)BDA and PCL(2000)(80)BDA is presumably due to the high crystallinity [18] and more hydrophobic nature of higher molecular weight PCL chains in the SPUU blocks. The narrow molecular weight distribution may also be one of the reason for slower degradation of PCL(1250)(70)BDA and PCL(2000)(80)BDA shown in Table 1.…”

Preparation and properties of biodegradable polyurethane networks from carbonated soybean oil

“…The most common approach for rendering polyurethanes to be hydrolytically degradable is the introduction of hydrolytically labile polyester soft segments such as polyhydroxyacids, polycaprolactone (PCL), polylactides and their copolymers into the backbone of polyurethanes. The amount of incorporating hydrophilic polyols and its molecular weight significantly affected the mechanical properties, water absorption, calcification and hydrolytic degradation [9][10][11][12][13][14][15][16].…”

Preparation and Characterization of Resorbable Hydrogel Membranes Useful for Tissue Engineering

“…[17,18] The objectives of the present study are to prepare biodegradable copolyesters ( Fig. 1) with a wide span of mechanical properties and their porous membranes and to evaluate the influence of the polymer structure in their biocompatibility.…”