Welding dynamics in an atomistic model of an amorphous polymer blend with polymer–polymer interface |
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| Authors: | Dmitry G Luchinsky Halyna Hafiychuk Vasyl Hafiychuk Kenta Chaki Hiroya Nitta Taku Ozawa Kevin R Wheeler Tracie J Prater Peter V E McClintock |
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| Institution: | 1. KBR, Inc., NASA Ames Research Center, Moffett Field, California, USA;2. Materials Science Section, Engineering Technology Division, JSOL Corporation, Tokyo, Japan;3. NASA Ames Research Center, Moffett Field, California, USA;4. NASA Marshal Space Flight Center, Huntsville, Alabama, USA;5. Department of Physics, Lancaster University, Lancaster, UK |
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| Abstract: | We consider an atomistic model of thermal welding at the polymer-polymer interface of a polyetherimide/polycarbonate blend, motivated by applications to 3D manufacturing in space. We follow diffusion of semiflexible chains at the interface and analyze strengthening of the samples as a function of the welding time tw by simulating the strain–stress and shear viscosity curves. The time scales for initial wetting, and for fast and slow diffusion, are revealed. It is shown that each component of the polymer blend has its own characteristic time of slow diffusion at the interface. Analysis of strain–stress demonstrates saturation of the Young's modulus at tw = 240 ns, while the tensile strength continues to increase. The shear viscosity is found to have a very weak dependence on the welding time for tw > 60 ns. It is shown that both strain–stress and shear viscosity curves agree with experimental data. |
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| Keywords: | molecular dynamics polymer blend polymer interfaces reptation strength of the interface welding |
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