| In the thesis, demonstrated amine epoxy curing agent was prepared by cardanol, which extracted from natural cashew nut shell, reacted with formaldehyde and multivariate amine e.g. diethylenetriamine, xylylenediamine, triethylenetetramine and isophorone diamine, etc. The synthesis process technology and the performance of the epoxy paint film were discussed by the method of orthogonal experiment and single factor experiment. The structure of the curing agent and the heat resistance property of epoxy paint film were characterized by FT-IR and TGA. The performance comparison of epoxy(E-51) film from the synthetic cardanol aldehyde amine and commercial phenol aldehyde amine was studied.In preparation of cardanol aldehyde diethylenetriamine, the influence factors on the performance of curing agent were discussed, such as the reaction time, n (phenolic):n (aldehyde):n (amine) and dehydration pressure etc. The results showed that the coating gel time was 29min, surface drying time and hard drying time were 48min and 22h, adhesion was 1st level, pencil rigidity was 3H and the resistance impact was 48kg-cm. At n (phenolic): n (aldehyde):n (amine)=1:1.2:1.4, after reacting for 2h at 95℃. and the dehydration stress at 0.0098Mpa, the pencil rigidity of the film was 3H. The IR spectrum showed that compared with the intermedium cashew phenolic methanol, the absorption peaks in the range of 3450～3100 cm-1 were broadened, because the cardanol methanol hydroxymethyl reacted with amine and a new group as -NH- generated, and the asymmetric and the symmetric stretching vibration of the group -NH- at 3400cm-1 overlaped with that of the phenolic hydroxyl, the absorption peak was drawn down:characteristic absorption peak of the uC-N was found at wavenumber about 1100cm-1, which proved generation of the cardanol aldehyde diethylenetriamine. The TG curve showed that the weight loss of film of the commercial phenol aldehyde amine happened at 138～310℃and that of the synthetic cardanol aldehyde amine curing agent did not happened at the temperature, the weight loss rate of it was 10% at 318.4℃, the maximum weight loss rate of it was got at 373.2℃, higher than that of the former.In preparation of modified triethylenetetramine epoxy curing agent, single factor experimental results showed that the film gel time was 28min, surface drying time and hard drying time were 48min and 21h, adhesion was 1st level, pencil rigidity was 3H and the resistance impact was 48kg-cm. At n (phenolic):n (aldehyde):n (amine) 1:1.2:1.3, after reacting for 2h at 95℃, and the dehydration stress at 0.0098Mpa, the pencil rigidity of the film was 3H. The IR spectrum showed that compared with the intermedium cashew phenolic methanol, C-N bond and-NH-bond appeared in the synthetic samples. The TG curve showed that the weight loss of film of the commercial phenol aldehyde amine happened at 138-310℃and that of the synthetic cardanol aldehyde amine curing agent did not happened at the temperature, the weight loss rate of it was 10% at 331.1℃, the maximum weight loss rate of it was got at 374.2℃, higher than that of the former. The corrosion resistance results show that the films of the cardanol aldehyde triethylenetetramine was better than the cardanol aldehyde diethylenetriamine in acetone solvent.In preparation of xylylenediamine curing agent modified by cardanol, the results of method of orthogonal experiment and single factor experiment showed that the film gel time was 30min,surface drying time and hard drying time were 50min and 22h, adhesion was 1st level,the pencil hardness was greater than3H, and the resistance impact was 50kg-cm. At n (phenolic):n (aldehyde):n (amine)=1:1.2:1.3, after reacting for 3h at 95℃, and the dehydration stress at 0.0098Mpa, the pencil rigidity of the film was 3H. The IR spectrum showed that compared with the intermedium cashew phenolic methanol, generation the cardanol aldehyde xylylenediamine.The corrosion resistance results showed that the film of synthesis curing agent was better than commercial phenol aldehyde in acid, alkali, acetone and gasoline, etc. The TG curve showed that the weight loss of film of the commercial phenol aldehyde amine happened at 138-310℃and that of the synthetic cardanol aldehyde amine curing agent did not happened at the temperature, the weight loss rate of it was 10%at 331.1℃, the weight loss rate of it was 50% at 461.1℃,the maximum weight loss Rate of it was got at 374.2℃, higher than that of the former.The synthsis conditions and performance of the cardanol aldehyde isophorone diamine curing agent were studied. The results showed that the coating gel time was 30min,surface drying time and hard drying time were 60min and 22h, adhesion was 1st level, the pencil rigidity of the film was 3-4H and the resistance impact was 50kg. cm tensile strength and flexural strength were47.5 Mpa and 49.6 Mpa. At n (phenolic):n (aldehyde):n (amine)= 1:1.1:1.3, after reacting for 3h at 95℃, and the dehydration stress at 0.0098Mpa. The IR spectrum showed generation cardanol aldehyde isophorone diamine. The TG curve showed that the films heat resistance of the synthetic cardanol aldehyde amine curing agent was better than the commercial phenol aldehyde amine.The film properties of the synthesis amine curing and commercial phenolic amine was studied, the resistance corrosion and resistance impact of the synthesis cardanol aldehyde amine film was better than the commercial phenol aldehyde amine. This related long alkyl chain of cardanol molecules. Film resistance impact of the cardanol aldehyde isophorone diamine and cardanol aldehyde xylylenediamine were improved obviously. Compared with cardanol aldehyde fat amine, and it can achieve 50kg·cm, it may be derived from the aromatic ring or the alicyclic structure. And then the structure of saturated naphthenic of cardanol aldehyde isophorone diamine made the film more resistant to solvents such as petrol and acetone.
|
PDF Full Text Request