کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
810990 | 1469128 | 2013 | 10 صفحه PDF | دانلود رایگان |
The intermixing between urethane acrylate (UA) prepolymer and acrylated epoxidized soybean oil (AESO) by thermal polymerization results in a product with promising properties for biomedical application. The results of dynamic mechanical analysis (DMA) performed on the polymerized UA, in a limited range of frequencies (0.5–10 Hz), have raised questions related to the origin of relaxations. Whether a molecular motion can be associated with a relaxation process was ascertained by performing experiments in a much larger frequency range, in a step-scan DMA experiment. The particularities of this experiment made possible to evidence unequivocally the α-relaxations for the urethane domains, organized in a hydrogen bond physical network, and to register the transformations associated with the breaking of hydrogen bonds. Incorporation of AESO has gradually loosened the physical network and transformed it into a mixed urethane-AESO chemical network. The properties of urethane-AESO networks are ruled by the double function of AESO: plasticizer and crosslinker. The evolution of secondary relaxations reflected also the changes that occur in the urethane-AESO samples. During the step-scan procedure supplementary changes were induced in the samples with high AESO content, at high temperature. The morphology of the networks was investigated by electronic microscopy studies.
Figure optionsDownload high-quality image (321 K)Download as PowerPoint slideHighlights
► Thermo-mechanical behavior of polyurethane-soybean oil structures was investigated.
► The origin of multiple tan δ peaks in the DMA behavior of was elucidated.
► Step-scanning temperature experiment showed the formation of network type structures.
► Soybean oil had a toughening effect on the polyurethane without strength decreasing.
Journal: Journal of the Mechanical Behavior of Biomedical Materials - Volume 17, January 2013, Pages 317–326