The Study on the Interface Modification of Polyacetal(POM)/ Polytetrafluoroethylene(PTFE) Composites.

• Main Authors: Chou, Ruei-Shu, 周瑞樞
• Other Authors: Chi-Yuan Huang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/09869624831999932635

碩士 === 大同工學院 === 材料工程學系 === 85 === The various kinds of PTFE fibers were added into POM to increase the wear resistance and to decrease the frictional coefficient of POM. However, PTFE has a low surface energy, resulting in weak adhesion donding and the decrease of mechanical properties. To enhance the adhesion between the matrix and fiber, the author used argon plasma to treat the surface of PTFE fiber(PPTEF) and then the AAm was graffted onto the surface of PPTFE fiber(AAm-g-TFE). The experiment parameters in this investigation were RF ower of plasma, plasma treatment time, concentration of grafting monomers,and grafting time. The results obained were as followes: 1. The self-designed rotary plasma equipment could efficiently to modify the PTFE fibers as the same as PTFE films in wo parallel Cu disk before, resulting producing C=C, oxygen- containing groups and croslinking on the surface which could be comfirmed by FTIR using PR method and XPS measurement. 2. From SEM photographs and the spectrum of FTIR, low RF power of plasma treatment could modify PTFE fibers efffectively. On the contrary, higher RF power such as exceeding 60W lead to unveiling of fresh PTFE, which decreased the effect of modificattion. 3. PTFE fibers treated by low RF power of plasma treatment both decreased the frictional coefficient and Taber wear factor as a result of the improvement of adhesion between PTFE fiberss and a result of the imporvement of adhesion between PTFE fibers and POM mattrix. However, free radicals, oxidation and eroxides produced by lasma treatment processing would destroyed the strctre of POM matrix, and lead to decrease of mechanical properties of POM/PTFE composites. 4. From the spectrum of FTIR and XPS of AAm-g-PPTFE fibers, the degree of grafting AAm was direct proportion to grafting concentration and grafting time, and PPAM formed a thin film on the surface of TFE fiber according to SEM photographs of AAm-g-PPTFE fibers. 5. According to the length of ull-out and holes between POM and fibers on the fractured surfaced surface, the sequence of strength of adhesion between matrix and fibers was POM/ AAm-g-PPTFE > POM/PPTFE > POM/PTFE. 6. As a result of PAAm of forming on the surface of PPTFE fibers was harmful to slide application, frictional coefficient and Taber wer factor of POM/AAm-g-PPTFE composites increased with increasing grafting time. 7. The adhesion between POM and fiber had been enhanced by using plasma to treat the PTFE fiber and then AAm grafting. As a result the elongation and impact strength of POM/AAm-g- PPTFE were increased.