以废聚酯制备聚氨酯涂料

Preparation of polyurethane coatings with waste polyester

以2，4-甲苯二异氰酸酯与三羟甲基丙烷制备了含有—NCO的A组分，将废聚酯通过醇解、酯化、缩聚等步骤制得不饱和聚酯，再与N，N-二甲基苯胺混合均匀作为含有-OH的B组分，将A、B两组分混合制得聚氨酯涂料。讨论了A、B组分的合成王艺，获得了最佳合成条件：制备A组分时，m（TDI）：m（TMP）=3．86～3．89，θ=（85±5）℃，t=1～1．5h：制备B组分时，θ（醇解）=190～210℃，t（醇解）=3～3．5h；θ（酯化）=130～150℃，t（酯化）=100min；θ（缩聚）=200℃。当mA：mB=1．05：1时，所得涂膜表面坚硬光滑，附着力0级，硬度6H，耐水性测试240h无变化，盐雾试验48h无变化。

Component A containing -NCO was synthesized with TDI and TMP, and component B containing -OH was gained from a mixture of N, N-dimethylaniline and unsaturated polyester obtained by alcoholysis, esterification and condensation of waste polyester. The polyurethane coating was prepared by mixing component A and B. The synthesis processes of component A and B were discussed. The optimal conditions were gained as follows： component A prepared in a condition ofm （TDI） ： m （TMP） = 3.86 - 3.89, θ = （85 ± 5） ℃ and t = 1 - 1.5 h; component B prepared at θ （alcoholysis） = 190 - 210 ℃, t （alcoholysis） = 3 - 3.5 h; θ （esterification） = 130 - 150 ℃, t （esterification） = 100 min; θ （condensation） = 200 ℃. The polyurethane coating which was prepared when mA ： mB = 1.05：1 has a hard and velvet appearance, adhesion of 0 grade and hardness of 6H. Coating＇s appearance was unvaried after 240 h of water resistant test and 48 h of salt spray test.