title: Morphology of chemically crosslinked ultrahigh molecular weight polyethylene.
abstract: Morphological characterization of chemically crosslinked ultrahigh molecular weight polyethylene was performed by differential scanning calorimetry and scanning electron microscopy. The lamellar thickness of nascent UHMWPE inferred from DSC endotherms showed a very broad distribution, which was reduced significantly after melting and recrystallizing in DSC. Peroxide crosslinking further reduced the lamellar thickness distribution compared to uncrosslinked samples. After gamma-irradiation, a slowly cooled peroxide-free sample showed a greater increase in lamellar thickness distribution. Examination of the morphology of freeze-fractured surfaces by SEM showed that a slowly cooled peroxide-free UHMWPE exhibited a rougher fracture while chemically crosslinked samples showed a smoother fracture. After compression molding at 300 degrees C for 2 h, the grain boundaries between particles disappeared for all UHMWPE samples, indicating a complete fusion of the original flakes.
authors.affiliation: Department of Materials Science and Engineering, University of Southern California, Los Angeles 90089-1211, USA.
authors.forename: F W
authors.initials: FW
authors.lastname: Shen
authors.forename: H A
authors.initials: HA
authors.lastname: McKellop
authors.forename: R
authors.initials: R
authors.lastname: Salovey
mesh_terms: D002152:Calorimetry, Differential Scanning; D003432:Cross-Linking Reagents; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D011095:Polyethylenes / Q000737:chemistry*; D011208:Powders
chemical_list: D003432:Cross-Linking Reagents; D011095:Polyethylenes; D011208:Powders