The Research On The Preparation Of The Modified Polymers By Nano-TiH₂ Via Microwave-assisted Ball Milling And The Properties Of The Composite Coatings

In contemporary the preparation of nanocomposite coatings is an important method of the development of coatings. However, the improvement of dispersibility stability of the nanoparticles and compatibility between nanoparticles and matrix remains a challenge for obtaining high performance nanocomposite coatings. To overcome this problem, the surface modification of nanoparticles is usually needed. In this paper, the surface modification of TiH₂ with epoxy resin was carried out via microwave-assisted ball milling and the modified polymers by nano-TiH₂ were characterized by XRD, SEM,TEM, TG and FTIR. Then, physical performance of the coatings?MBM coatings? which added surface modified nano-TiH₂ was tested. At the same time, soaking, neutral salt spray test and electrochemical measurement system were performed to investigate the anticorrosive property of the coatings. In order to study the influence of the microwave-assistance on the surface modification of nano-TiH₂, ball milling experiments without microwave-assistance were performed and compared. Also the physical performance and anticorrosive property of the MBM coatings, the epoxy coatings?EP coatings? and the coatings?BM coatings? which added the products obtained by ball milling were investigated.?1? The particle size of TiH₂ were decreased to nanometer-scale?about 100nm?and the nano-TiH₂ were modified with epoxy resin successfully during the microwave-assisted balling milling process, when the weight ratio of balls to reactant was 10:1, the rotation speed of the stirrer was 500r/min and grinding time was 20 h.The TG measurements indicated that the grafting ratio of epoxy resin was about5.56%. But for the sample obtained by ball milling, no epoxy resin was detected on the surface of nano-TiH₂.?2? FTIR was performed to characterize the structure of the products?mixture slurry? treated by ball milling and microwave-assisted ball milling. The results show that the peak for epoxy groups?914cm-1? disappeared when the milling time increased to 20 h, demonstrating that the ring-opening reaction of epoxy groups took place during the microwave-assisted ball milling process. However, for the mixture slurry milling without microwave-assistance, the characteristic absorption peaks of epoxy resin did not change, even though the milling time was prolonged to 50 h. The mixture slurry treated by ball milling or microwave-assisted ball milling for 20h?BM-20 h or MBM-20h? was diluted, filtered, washed repeatedly and dried, then the sample?powder? were obtained. Also FTIR was also used to characterize the powder. The results indicate that many characteristic absorption peaks of epoxy resin appeared for the MBM-20 h sample except the epoxy groups?914cm-1?, which demonstrated the that ring-open of epoxy groups was really happened. But for the BM-20 h sample, no characteristic absorption peaks of epoxy resin appeared which meant that the surface modification of nano-TiH₂ was failed for ball milling.?3? Judging from the comparative experiments with and without microwave, only microwave-assisted ball milling process achieved the surface modification of the nano-TiH₂, indicating that the coupling effect of mechanical force and microwave played a key role during the process. Furthermore, the sedimentation test show that dispersibility stability of nano-TiH₂ and compatibility of nano-TiH₂ with matrices were improved.?4? The performance testing results show that the MBM coatings had best physical and anticorrosive properties. The flexibility and adhesion of the BM coatings were almost the same with the EP coatings. But for MBM coatings, the flexibility and adhesion were higher. The Tafel polarization curves show that the MBM coatings had highest corrosion potential?Ecorr?, lowest corrosion current density?Icorr? and corrosion rate?Rcorr?. Also the EIS results indicated that the low frequency impedance of the MBM coatings were higher. In addition, the soaking and neutral salt spray test both demonstrated that the MBM coatings had high corrosion resistance.