| Fender, as an elastic buffer device of dock or ship edges, is mainly used to slow the moorage impact of ship to dock or ship to ship, to prevent or eliminate the damage of ships and docks. Most of the fenders on the market is made of rubber and polyurethane. However, due to being soaked in sea water, eroded, impacted by storms, tides, alternating diurnal temperature and salt spray environment, as well as UV irradiation longterm, fender’s corrosion and aging are becoming increasingly prominent, seriously endangering their safety and durability. The coating technology is an important and effective way of protecting material. Polyurea is a high performance elastomers, aromatic polyurea and conventionalaliphatic polyurea have been widely used in the preparation of high weather resistance and chemical resistant protective coating. In the present study, anti-UV polyurea were prepared and researched.Then, FTIR,1H-NMR,DSC, TGA, XRD, UV absorption spectroscopy, mechanical properties and adhesion testing methods were empolyed to analysis their relationship between performance and formula. The main results are as follows.By two steps, pre-polying and chain extending, a series of polyurea were synthesized. Then,the basic raw materials, formulation and process were filtered out as follows: E100, E300, IPDA as the basic components of compounded chain extender, D2000 as the reaction of amino terminated polyether,1.05 as the designed eigenvalue,10℃as pre-poly temperature, 25%(wt%) as solid content, the Petri dish pasted with release paper to easily demolding as the mold, volatiling of solvent at room temperature for 72 hours,60℃in heating oven for 3 hours,85℃in 0.1Mpa vacuum oven for 1h,110℃in 0.1 Mpa vacuum oven for 3h as the film-forming process.Anti-UV polyureas of aromatic R-1 series, R-2 series and aliphatic R-4 series, were characterized by 1HNMR, and results indicate that the products conform to the designed structure. The adhesion test indicate that, adhesion of R-1 and R-2 are very good,but R-4, due to chain extender including phenylene diamine, its adhesion is too low to meet the construction demand. Results of TGA, XRD and DSC indicate that the thermal degradation temperatures of R-1 & R-2 are above 380℃, and their sturctures are Amorphous. On account of a larger hard-segment content,R-2 has a higher thermal degradation temperature than R-1 about 15℃.Besides, ultraviolet absorption agent is also able to improve the thermal degradation temperature about 10℃. UV spectra result indicate that R-2 with a larger hard-segment content is more resistant to UV than R-1 for reason of less phenyl ring content.By adding UV absorber of UV327, UV-resistant performance of the material can be improved by about 1 times. The solvent resistance tests indicate that the aromatic polyurea samples can be long-term resistance to sea water and alkali, but intolerant of acid and organic solvents. Mechanics and aging tests indicate that the performance of material R-2 meet the requirements of fender plastic material in Chemical Industry Standards HG/T 2866-2003, and R-l’s tensile strength don’t meet the standards for reason of lower hard-segment content.All the test results indicate that the performance of the formula of R-2 polyurea is in line with the requirements of the rubber fender coating in the HG/T 2866-2003.The formula can be applied widely to achieve anti-UV in fender coating, and can be also widely used in other ship’s components by adjusting the polyurea formula. |
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