Open-Cell Aliphatic Polyurethane Foams with High Content of Polysaccharides: Structure, Degradation, and Ecotoxicity

Abstract

Fully aliphatic (isocyanurate ring-based) polyesterether polyurethane (PUR) foams have been developed, and the influence of starch and 2-hydroxyethyl cellulose (HEC) additives on their structure, properties, ecotoxicity, and (abiotic and biotic) degradation has been studied. These PUR foams designed as hydrophilic open-porous materials are predisposed to enzymatic hydrolysis with potential application as cellular carriers and an alternative nutrient source for activated sludge in wastewater treatment plants. In comparison to the neat (nonmodified) PUR foam, the PUR foams with incorporated starch and HEC modifiers exhibited a tougher character and a slightly increased open-cell content but on the other hand a significantly coarser cellular structure with much larger cell sizes and reduced water absorption. The progress of 6-week abiotic hydrolysis was characterized in detail, showing almost a complete decomposition of ester groups, a partial degradation of urethane linkages, and a fully intact isocyanurate ring. The extent of biodegradation by means of bacteria was similar for all tested PUR foams, while fungus biodegradation was more efficient in starch and HEC-modified PUR foams. The leachates from both starch-and HEC-modified foams exhibited somewhat higher ecotoxicity for higher organisms, here represented by Daphnia magna, due to higher contents of leached substances.

Development of Leather Fiber/Polyurethane Composite with Antibacterial, Wet Management, and Temperature-Adaptive Flexibility for Foot Care

“…17 A broad and strong peak at 1100 cm −1 is attributed to ether bond C−O−C stretching. 18 These bands verified the typical polyurethane structure in PPU. In the spectrum of PHMG, there is a characteristic absorption peak at 1640 cm −1 , which can be attributed to the C�N stretching vibration.…”

“…The peak at 1535 cm –1 is associated with the bending vibration of N–H (from −CONH−) . A broad and strong peak at 1100 cm –1 is attributed to ether bond C–O–C stretching . These bands verified the typical polyurethane structure in PPU.…”

Fabrication and characterization of novel polyurethane Encapsulant with excellent underwater acoustic transparency and hydrophobicity

“…[24] The presence of these characteristic peaks indicated the formation of urethane. [25,26] Additionally, the intensive peaks located at 765 cm À1 , 910 cm À1 , and 968 cm À1 were assigned to the traces of cis-1,4 isomers, 1,2-vinyl and trans-1,4 isomers, respectively. [27] In the FT-IR spectra of FPU, the peak at 1264 cm À1 was ascribed to the Si-CH 3 group.…”

Biobased Ultralow-Density Polyurethane Foams with Enhanced Recyclability

“…Tailor-made polyester polyols bearing hydrolyzable ester groups are key for the fabrication of PUR foams with enhanced degradability . Additionally, introducing hydrophilic entities such as glycol chains into the PUR structure can further accelerate the degradation rate. − …”