| Thermoplastic polyurethane adhesives (TPU) have excellent mechanical, adhesive and resistent low-temperature characteristics, and can be widely applied in many fields. But aromatic TPU are susceptible to aging and degradation in the light for a long time, and the results are that the adhesive strength declines, the adhesive layer yellows and the application effect is not good. In order to improve the anti-aging performance of TPU, except for selecting non-aromatic raw materials, ageing-resistant agents were added to the reaction system for TPU to improve the anti-aging performance of TPU but not to increase the cost of TPU. Thus, the effect of ageing-resistant agents on the technology and properties of TPU was studied in this paper. Moreover, bismuth lauric as a non-toxic catalyst in the application of TPU synthesis was also studied at the same time.In the experiment, TPU were synthesized with poly-butylene adipate glycol (PBA3000), 1,4 - butanediol (BDO), diphenylmethane diisocyanate (MDI) and ageing-resistant agents (UV absorbers, hindered amine light stabilizers, antioxidants) by one-step method. The influences of the following on the properties of TPU were firstly studied. The factors included molecular weight of PBA, BDO addition amount, R value (molar ratio of -NCO/-OH), reaction temperature and post cure conditions. Secondly, the influences of kinds, amount and associative effect of ageing-resistent agents on the mechanical strength and anti-aging performance of TPU were discussed. The results were as follows: the conditions of high quality TPU obtained were PBA molecular weight of 3000, molar ratio of BDO to PBA 0.40, R value from 0.99 to 1.00, rection for 4min at 90~95℃, curing for 5.5h at 120~130℃. In the synthesis of TPU, when UV-329 as a UV absorber, UV-622 as a hindered amine light stabilizer and 1010 as an antioxidant were respectively added to TPU the anti-aging properties of TPU were improved only at certain extent. But, when UV-329, UV-622 and 1010 were simultaneously added to the TPU by composite ageing-resistant agents, the anti-aging properties of TPU were significantly improved by the help of associative effect among the above three ageing-resistent agents. The optimal mass ratio among UV-329, UV-622 and 1010, was 3:3:2. the total amount of composite ageing-resistant agents was 1.7% on the basis of PBA3000. The results showed that, although the properties of TPU containing composite ageing-resistant agents were slightly lower than those of TPU no-containing composite ageing-resistant agents, the properties of the latter declined more obviously than those of the former in the light of UV for 150h. The property changes of the latter were as follows: tensile strength declined 44%, elongation at break declined 66% and adhesive strength declined 25%. However, the property changes of the former were as follows: tensile strength declined 10%, elongation at break declined 26% and adhesive strength declined 9.5%. In addtion, the yellowing grade of TPU containing composite ageing-resistant agents could reach 4.1 in the light of UV for 8h.Dibutyltin dilaurate (DBTDL) as a catalyst in the production of TPU is harmful to human health, so TPU containing DBTDL is not suitable for food, medicine, et al. In this paper, synthesis of bismuth laurate as a non-toxic catalyst and its application in the production of TPU were also studied. At 90~95℃, sodium laurate was first synthesized by the saponification between lauric acid and sodium hydroxide, then bismuth laurate was obtained by the double decomposition reaction between sodium laurate and bismuth nitrate. When the addition amount of bismuth laurate was 0.04% on the basis of PBA3000, reaction time of TPU was shortened from 4 min to 2 min, so bismuth laurate had significantly catalytic activity for–NCO/-OH reaction and improved the properties of TPU to some extent.
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