Effect of molecular weight on the physical properties of poly(ethylene brassylate) homopolymers
| Autor: | Haritz Sardon, Jose-Ramon Sarasua, Jorge Fernández, Hegoi Amestoy, Miren Aguirre, Aitor Larrañaga Varga |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Polyesters Biomedical Engineering Analytical chemistry chemistry.chemical_element Biocompatible Materials 02 engineering and technology 010402 general chemistry 01 natural sciences Bismuth Catalysis Biomaterials chemistry.chemical_compound Ethers Cyclic Ultimate tensile strength Polymer chemistry Molar mass 021001 nanoscience & nanotechnology 0104 chemical sciences Molecular Weight Monomer chemistry Mechanics of Materials Degradation (geology) Crystallite Deformation (engineering) 0210 nano-technology |
| Zdroj: | Journal of the mechanical behavior of biomedical materials. 64 |
| ISSN: | 1878-0180 |
| Popis: | Poly(ethylene brassylate) (PEB) is a biodegradable polyester that nowadays is of particular interest owing to its poly(e-caprolactone)-like properties (with a T g at −30 °C and a T m at 70 °C) and the low-cost of its monomer. However, it is not simple to achieve high molar masses with conventional catalysts. In this work, high molar mass PEBs, characterized by SEC-MALS, were successfully synthesized using triphenyl bismuth (Ph 3 Bi) as catalyst. Then, with the aim of evaluating the impact of the molecular weight on the physical properties, several PEBs ranging from 27 to 247 kg mol −1 were prepared. It was demonstrated that above a M w of 90 Kg mol −1 , PEB behaved in a constant manner. PEBs with lower molecular weight ( −1 ) showed lower values of T g (~(−35 °C)) and presented a melting peak that was split into three or four different peaks while their crystallites started to melt earlier (at ~30 °C). In addition, these PEBs were more sensitive to thermal degradation (two additional stages of degradation were observed) and, what is more important, were found to be prone to brittle fracture. As the M w rose, the PEB samples became more ductile and those PEBs with a molecular weight above 90 Kg mol −1 possessed deformation at break values higher than 800%, secant modulus in the 296–324 range and ultimate tensile strength of >20 MPa. |
| Databáze: | OpenAIRE |
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