title: Laser-Marking Mechanism of Thermoplastic Polyurethane/Bi2O3 Composites.
abstract: Using bismuth oxide (Bi2O3) as a laser-marking additive and thermoplastic polyurethane (TPU) as the matrix, TPU/Bi2O3 composite materials were prepared by melt blending in a torque rheometer. The sheet samples prepared from the TPU/Bi2O3 composites were treated in air by scanning with a neodymium-doped yttrium aluminum garnet (Nd: YAG) pulsed laser beam at a wavelength of 1064 nm. Compared with the pure TPU sample, the laser-marked composite samples exhibited differences in marking contrast as the Bi2O3 content increased from 0.1% to 1.0% based on stereomicroscope analysis. Scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, thermogravimetry analysis, and X-ray diffraction were used to characterize the laser-marked surface material of the composite samples. Furthermore, a mechanism for the laser-effected darkening of the TPU/Bi2O3 composites was proposed. The results herein indicated that the addition of the Bi2O3 laser-sensitive additive to TPU resulted in laser darkening of the TPU/Bi2O3 composites. The marking contrast and visual appearance of the surface of the TPU/Bi2O3 composites after laser irradiation was due to a synergistic effect consisting of carbonization via TPU pyrolysis and reduction of Bi2O3 to black bismuth metal.
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhong
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Cao
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Qiu
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: Dun
authors.initials: D
authors.lastname: Wu
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: Huili
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University , Changzhou 213164, China.
authors.forename: He
authors.initials: H
authors.lastname: Zhu
keywords: bismuth oxide; carbonization; laser marking; reduction; thermoplastic polyurethane