Plasma treatment of polymer powders
US5439984A · kind A · utility
Inventors
Key dates
| Filing date | Dec 22, 1993 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Dec 22, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/251
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Surfaces of fine polystyrene (PS) and polymethyl methacrylate (PMMA) powders were modified by exposure to the downstream products of a nitrogen or oxygen microwave plasma. The effects of nitrogen and indium incorporation in the powder surface were studied with emphasis on variations in the triboelectric properties of the powder. X-ray photoelectron spectroscopy (XPS) was utilized to determine the changes in surface elemental composition. After nitrogen plasma treatment, the C 1s peak profiles suggested the formation of amines in the case of PS, and the formation of imines and amides in the case of PMMA. Oxygen plasma treatment suggested the formation of hydroxyl and carbonyl groups on the surfaces of both PS and PMMA. After treatment with a nitrogen or oxygen plasma, the charge-to-mass ratio (Q/M) of PS and PMMA powders in contact with carrier particles was measured using the cage blowoff method. The surface charge density (Q/A) was calculated from Q/M. The Q/A of nitrogen plasma-treated PS powder was seen to shift towards positive charge with small increases in the nitrogen concentration. The Q/A of oxygen plasma treated PS powder initially shifted toward negative charge, but chan…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.