Grafting of Acrylic Acid Onto Polytetrafluoroethylene (PTFE) Micropowder via Pre-Irradiation
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摘要: 采用预辐照法对聚四氟乙烯(PTFE)微粉进行接枝丙烯酸改性，以改善微粉在水溶液中的分散性。研究了丙烯酸体积分数、适量浓H2SO4的添加、阻聚剂质量浓度、反应时间等因素对接枝率的影响。结果表明，接枝率随着丙烯酸体积分数(在50%以内)增加而单调递增；适量浓H2SO4能增强阻聚剂的阻聚效果，提高接枝率；在本实验条件下，阻聚剂最佳质量浓度为0.8 g/L；反应在3 h后接枝率即可达饱和。当丙烯酸在PTFE微粉上的接枝率达到10%以上时，改性PTFE微粉在氢氧化钠溶液中可达到均匀分散。
Abstract: Grafting of acrylic acid (AAc) onto the surface of PTFE micropowders was performed by pre-irradiation method, in order to improve their dispersion in aqueous solution. The effects of various experimental parameters on the degree of grafting (G） were separately investigated, including: volume fraction of AAc, proper addition of concentrated sulfuric acid, mass fraction of inhibitor and reaction time. The result shows that G is increasing with increment of AAc concentration below 50%, and can be enhanced by adding a proper amount of sulfuric acid. Under our experimental conditions, G reached its saturated value when the mass concentration of the inhibitor was 0.8 g/L and the reaction time was 3 h. The introduction of more than 10% of poly(acrylic acid) chain on PTFE micropowders results in the good dispersion of PTFE micropowders in aqueous NaOH solution.
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Keywords:
- pre-irradiation /
- grafting /
- acrylic acid /
- PTFE micropowders
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