title: Supertough polylactide materials prepared through in situ reactive blending with PEG-based diacrylate monomer.
abstract: Supertough biocompatible and biodegradable polylactide materials were fabricated by applying a novel and facile method involving reactive blending of polylactide (PLA) and poly(ethylene glycol) diacylate (PEGDA) monomer with no addition of exogenous radical initiators. Torque analysis and FT-IR spectra confirm that cross-linking reaction of acylate groups occurs in the melt blending process according to the free radical polymerization mechanism. The results from differential scanning calorimetry, phase contrast optical microscopy and transmission electron microscopy indicate that the in situ polymerization of PEGDA leads to a phase separated morphology with cross-linked PEGDA (CPEGDA) as the dispersed particle phase domains and PLA matrix as the continuous phase, which leads to increasing viscosity and elasticity with increasing CPEGDA content and a rheological percolation CPEGDA content of 15 wt %. Mechanical properties of the PLA materials are improved significantly, for example, exhibiting improvements by a factor of 20 in tensile toughness and a factor of 26 in notched Izod impact strength at the optimum CPEGDA content. The improvement of toughness in PLA/CPEGDA blends is ascribed to the jointly contributions of crazing and shear yielding during deformation. The toughening strategy in fabricating supertoughened PLA materials in this work is accomplished using biocompatible PEG-based polymer as the toughening modifier with no toxic radical initiators involved in the processing, which has a potential for biomedical applications.
authors.affiliation: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China , Hefei, Anhui Province 230026, P. R. China.
authors.forename: Huagao
authors.initials: H
authors.lastname: Fang
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.forename: Qianghua
authors.initials: Q
authors.lastname: Wu
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Ding
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D003432:Cross-Linking Reagents / Q000737:chemistry; D003460:Crystallization; D055119:Elastic Modulus; D055595:Mechanical Phenomena; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D012212:Rheology; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D011091:Polyesters; C437167:poly(ethylene glycol)diacrylate; D011092:Polyethylene Glycols; C033616:poly(lactide)