第5章 己二酸、戊二酸、丁二酸在甲醇己二酸二甲脂混合溶剂中溶解度及关联根据前面混合二元酸甲酯化反应工艺与反应动力学研究发现，酯化剂甲醇是要求过量才能保证DBA 酯化高产率。

酯化剂甲醇在DBA 甲酯化反应体系中既是酯化剂也是反应体系溶剂，DBA 甲酯化过程涉及到DBA 在甲醇中溶解反应耦合过程，随着反应发生己二酸二甲酯不断生成，DBA 在甲醇与己二酸二甲酯混合溶剂中溶解反应耦合过程逐渐占用主导作用，因此研究DBA 在甲醇与己二酸二甲酯混合溶剂中固液相平衡有利于分析DBA 溶解平衡对反应的影响，为DBA 大规模生产提供可靠的基础工程热力学数据。

5.1混合二元酸在甲醇与己二元酸二甲酯混合溶剂中溶解度5.1.1混合二元酸在甲醇与己元酸二甲酯溶解度测定实验可靠性的验证混合二元酸在甲醇与混合二元酸二甲酯溶解度测定实验采用激光动态法,为了检验该装置的准确性，本实验做了己二酸在甲醇和醋酸中的溶解度，将测得的部分值与文献[45,49,62]进行比较，结果如图5.1~5.2，测量值与文献值基本吻合。

说明这套激光装置用来测定这三种二元酸在己二酸二甲脂和甲醇混合溶剂中的溶解度是可信的。

2802852902953003053103153203253303350.020.030.040.050.060.070.080.090.100.110.12实验值 文献值xT/K图5.1 己二酸在甲醇中的溶解度（□实验值△文献值[62]）2903003103203303403500.020.040.060.080.100.12实验值 文献1 文献2XT/K图5.2 己二酸在醋酸中溶解度（□实验值○文献值[45]△文献值[49]）5.1.2混合二元酸在甲醇与己二酸二甲酯混合溶剂溶解度本实验分别测定了己二酸、戊二酸、丁二酸在甲醇和己二酸二甲脂混合溶液中溶解度（甲醇的质量分数依次为0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9、1.0），其中S exp 为原始数据溶质的溶解度数据，x exp 为溶质的摩尔分数，w 1为混合溶液中己二酸二甲脂的质量分数，w 2为甲醇的质量分数，具体的溶解度数据如图表5.1~5.3所示：表5.1 己二酸在甲醇己二酸二甲脂混合溶剂中的溶解度T/K S exp /g x exp T/K S exp /g x exp w 1=1 w 1=0.4 293.15 0.3754 0.0045 287.05 12.6 0.0394 298.15 0.4480 0.0053 290.25 13.784 0.0429 303.15 0.5308 0.0063 292.55 15.186 0.0471 308.15 0.6107 0.0072 297.85 17.1166 0.0528 313.15 0.7800 0.0092 302.15 19.1536 0.0587 318.15 0.9754 0.0115 306.55 21.371 0.0650 323.15 1.1910 0.0140 309.55 24.075 0.0727 328.15 1.5280 0.0179 312.35 26.2226 0.0786 333.15 1.7750 0.0207 316.55 29.23 0.0869 338.15 2.6294 0.0304 321.55 33.0732 0.0972326.55 37.5988 0.1090 331.65 43.0132 0.1228 w 1=0.9 w 1=0.3 284.65 1.6024 0.0131 286.25 13.5646 0.0379 288.951.96240.0159290.9515.16460.0422294.75 2.373 0.0192 293.55 16.2908 0.0452 299.75 2.7594 0.0223 297.55 18.302 0.0505 303.95 3.1618 0.0254 300.65 20.8262 0.0570 307.35 3.6802 0.0295 304.65 23.0756 0.0628 311.75 4.1942 0.0335 308.95 26.0736 0.0704 315.45 4.736 0.0376 311.65 28.0506 0.0753 319.75 5.3432 0.0423 315.65 31.353 0.0834 323.85 5.9786 0.0470 320.25 35.785 0.0941 327.45 6.581 0.0515 324.45 40.7172 0.1057 330.85 7.2196 0.0563 328.95 45.9172 0.1176 w1=0.8 w1=0.2283.95 4.4 0.0270 285.25 13.8 0.0349 288.45 4.9528 0.0303 290.95 16 0.0402 293.25 5.587 0.0341 293.75 18 0.0450 298.75 6.4932 0.0394 297.65 20.3456 0.0506 302.75 7.3146 0.0442 301.45 22.3544 0.0553 308.05 8.4076 0.0504 304.55 24.886 0.0612 311.35 9.3114 0.0555 308.45 27.8884 0.0681 316.35 10.3958 0.0616 312.35 30.8378 0.0748 320.95 11.6254 0.0684 316.45 34.4424 0.0828 325.15 13.2318 0.0771 320.65 38.8932 0.0925 328.85 14.436 0.0836 324.65 44.3688 0.1041 331.75 15.5502 0.0894 328.55 50.0624 0.1160 w1=0.7 w1=0.1291.45 8.0194 0.0394 285.15 14 0.0323 296.15 8.7602 0.0429 289.15 16 0.0368 299.35 9.4904 0.0463 292.65 18 0.0412 302.45 10.439 0.0507 297.35 21 0.0477 305.35 11.4172 0.0552 300.65 23.4126 0.0529 309.05 12.5822 0.0605 304.45 26.1556 0.0588 312.25 13.8844 0.0663 308.85 29.9748 0.0668 315.45 15.3416 0.0727 311.15 32.574 0.0722 318.75 16.944 0.0797 315.35 36.8792 0.0809 323.05 19.142 0.0892 320.15 42.603 0.0923 326.45 20.8258 0.0962 324.65 48.611 0.1040 330.05 22.615 0.1037 327.65 54.6112 0.1153 w1=0.6 w1=0289.65 10 0.0412 284.85 14 0.0298 294.25 11.2 0.0459 288.95 16 0.0339 297.55 12.21 0.0498 291.45 18 0.0380 300.85 13.2472 0.0538 296.45 20.999 0.0440 304.85 14.9492 0.0603 299.45 23.4098 0.0488 308.65 16.666 0.0668 302.95 26.0174 0.0540 312.55 18.392 0.0732 306.95 29.6358 0.0610315.85 19.9936 0.0791 309.55 32.66 0.0668 319.05 21.859 0.0858 313.55 37.0676 0.0752 322.95 24.4664 0.0951 318.65 43.2644 0.0866 328.65 27.4558 0.1055 323.85 49.8798 0.0986 331.55 29.4888 0.1124 327.1557.21420.1115w 1=0.5 287.85 10.9814 0.0391 290.75 12.029 0.0427 294.55 13.4636 0.0475 298.35 15.0426 0.0528 302.35 16.8736 0.0588 306.25 18.929 0.0655 311.15 21.4544 0.0736 314.35 23.5396 0.0802 317.75 25.5964 0.0866 321.95 28.6232 0.0958 326.55 32.4864 0.1074 332.15 37.46720.12192802903003103203303400102030405060S /g (100g )-1T/Kw 2=0 w 2=0.1 w 2=0.2 w 2=0.3 w 2=0.4 w 2=0.5 w 2=0.6 w 2=0.7 w 2=0.8 w 2=0.9 w 2=1图5.3 己二酸在甲醇己二酸二甲脂混合溶剂中的溶解度（w 2甲醇质量分数）表5.2 戊二酸在甲醇己二酸二甲脂混合溶剂中的溶解度T/KS exp /gx exp (mole fraction)T/KS exp /gx exp (mole fraction)w1=1 w1=0.4294.85 4.348616 0.0542 289.15 78 0.2193 297.15 5.584235 0.0686 294.45 86 0.2364 300.85 7.069294 0.0853 298.15 94 0.2529 304.55 8.569319 0.1015 303.55 106 0.2762 306.35 9.748666 0.1139 307.45 118 0.2982 309.05 11.26805 0.1294 310.95 130 0.3188 310.75 12.78823 0.1443 315.65 146.64 0.3455 312.95 14.79012 0.1632 319.15 162.64 0.3693 315.25 17.2452 0.1853 322.35 181.48 0.3952 w1=0.9 w1=0.3291.95 20.0156 0.1546 289.95 88 0.2203 293.65 22.166 0.1684 296.35 99.72 0.2426 296.55 25.366 0.1881 300.65 109.48 0.2601 299.85 28.2676 0.2052 304.35 118.92 0.2764 302.75 31.4088 0.2229 307.65 129.12 0.2931 308.05 35.1888 0.2432 310.65 139.8 0.3099 312.55 39.5888 0.2656 314.15 153 0.3295 316.45 44.8432 0.2906 317.75 169.6 0.3526 320.85 53.3232 0.3275 321.15 187.84 0.3763 w1=0.8 w1=0.2289.25 32.984 0.1873 290.65 96 0.2177 292.75 37.146 0.2060 295.75 108 0.2384 296.35 41.2452 0.2237 299.85 120 0.2580 301.35 45.6504 0.2418 305.85 138.88 0.2870 303.95 49.8048 0.2581 310.65 154.08 0.3087 307.35 54.77716 0.2768 315.15 172.12 0.3328 312.05 60.96996 0.2987 318.15 185.32 0.3494 314.75 65.63676 0.3144 321.35 206.44 0.3743 316.35 71.56956 0.3333 322.55 219 0.3883 w1=0.7 w1=0.1289.45 46.824 0.2094 292.45 110 0.2251 293.85 51.8956 0.2269 295.85 118.5 0.2383 297.75 56.0524 0.2407 299.35 129.3 0.2545 301.15 60.2924 0.2543 302.95 141.7 0.2723 304.45 65.3848 0.2700 306.55 156.7 0.2927 308.35 72.1848 0.2899 310.35 172.9 0.3135 312.75 80.1848 0.3120 313.95 191.05 0.3353 317.25 89.5732 0.3363 317.15 212.3 0.3592 321.35 101.6532 0.3651 320.55 238.3 0.3862 w1=0.6 w1=0290.15 60 0.2219 293.55 118 0.2225 296.65 66.8 0.2410 295.25 122 0.2283 301.55 73.6 0.2591 297.25 128 0.2369304.65 81.6 0.2794 299.55 136 0.2480 308.45 91.04 0.3020 302.95 148 0.2641 312.35 101.32 0.3250 308.05 168 0.2895 316.35 113.76 0.3509 312.35 188 0.3132 319.65 126.16 0.3748 317.55 218 0.3459 323.75 144.48 0.4071321.55 248 0.3756 w 1=0.5293.05 74.16 0.2330 298.35 80.84 0.2488 301.35 84.764 0.2578 303.25 88.794 0.2667 306.25 95.914 0.2821 309.95 105.514 0.3018 313.45 116.594 0.3233 316.75 128.994 0.3458 320.55 146.2740.3747285290295300305310315320325050100150200250w 2=0 w 2=0.1 w 2=0.2 w 2=0.3w 2=0.4 w 2=0.5 w 2=0.6 w 2=0.7w 2=0.8 w 2=0.9 w 2=1S /g (100g )-1T/K图5.4 戊二酸在甲醇己二酸二甲脂混合溶剂中的溶解度表5.3丁二酸在甲醇己二酸二甲脂混合溶剂中的溶解度T/KS exp /g x exp (mole fraction) T/KS exp /g x exp (mole fraction) w 1=1 w 1=0.4 293.15 0.3341130.0049288.75120.0461298.15 0.409671 0.0060 293.45 13.2436 0.0506 303.15 0.482315 0.0071 297.65 14.2906 0.0544 308.15 0.616781 0.0090 301.45 15.3454 0.0582 313.15 0.675533 0.0099 304.35 16.3504 0.0618 318.15 0.746532 0.0109 307.35 17.371 0.0654 323.15 0.87153 0.0127 310.15 18.6924 0.0700 328.15 0.996839 0.0145 313.55 20.3924 0.0759 333.15 1.223796 0.0177 319.95 23.358 0.0860 338.15 1.703534 0.0245 325.95 26.3938 0.0961332.35 30.1078 0.1082 w1=0.9 w1=0.3289.05 2 0.0200 287.35 12.42 0.0427 296.65 2.4726 0.0246 291.65 13.7702 0.0471 303.35 2.7994 0.0278 295.95 15.1626 0.0517 309.15 3.05 0.0302 299.65 16.442 0.0558 313.75 3.3036 0.0327 303.05 17.6658 0.0597 317.75 3.719 0.0366 306.75 19.0462 0.0640 324.55 4.5722 0.0446 309.85 20.6684 0.0691 335.15 5.7322 0.0553 314.05 22.643 0.0752318.75 25.8154 0.0849323.05 29.3666 0.0954326.45 33.1626 0.1065 w1=0.8 w1=0.2289.45 4.4 0.0332 286.85 12.92 0.0402 296.35 5.11 0.0384 291.05 14.4124 0.0446 301.45 5.6252 0.0421 295.05 16.008 0.0493 306.55 6.2834 0.0468 298.85 17.7656 0.0545 308.65 6.6794 0.0496 302.45 19.4064 0.0592 312.85 7.3102 0.0540 306.15 21.1594 0.0642 318.95 8.4556 0.0620 309.85 23.043 0.0695 326.35 9.9602 0.0722 314.35 25.123 0.0753 331.85 11.6244 0.0833 318.65 27.843 0.0828323.55 30.697 0.0905328.25 34.299 0.1001 w1=0.7 w1=0.1290.95 7.1 0.0430 286.15 12.92 0.0368 297.15 7.8812 0.0475 290.35 14.6062 0.0414 302.45 8.6374 0.0518 294.15 16.2406 0.0458 307.45 9.6886 0.0578 297.45 17.8818 0.0502 311.85 10.5004 0.0623 301.15 19.8712 0.0554 315.65 11.4858 0.0678 305.35 22.1312 0.0614 319.45 12.8566 0.0752 309.35 24.4512 0.0674 325.95 14.4418 0.0837 313.75 26.7912 0.0733 331.65 16.2868 0.0934 317.55 29.3712 0.0798322.35 32.3586 0.0873 328.4537.1094 0.0988 w 1=0.6 w 1=0 289.35 8.4 0.0427 285.75 14 0.0366 294.55 9.24 0.0468 290.95 16.026 0.0417 299.15 9.94 0.0502 295.85 17.8548 0.0462 303.15 11.23 0.0563 298.15 19.787 0.0510 306.15 11.9538 0.0598 302.55 22.2064 0.0568 309.65 13.0676 0.0650 307.85 24.8964 0.0633 314.05 14.2998 0.0707 311.35 27.1644 0.0686 320.25 16.2998 0.0797 314.35 29.721 0.0746 325.45 18.1988 0.0882 319.85 33.4262 0.0832 330.6520.59880.0987324.45 36.6426 0.0904 327.7539.64660.0971w 1=0.5 290.95 11 0.0480 295.05 11.868 0.0516 298.15 12.7984 0.0554 301.35 13.7676 0.0594 304.55 14.7016 0.0631 308.35 15.9414 0.0681 312.25 17.5672 0.0745 318.45 19.8948 0.0836 323.95 22.1952 0.0923 331.15 25.2560.10372802903003103203303400510152025303540S /g (100g )-1T/Kw 2=0 w 2=0.1 w 2=0.2 w 2=0.3 w 2=0.4 w 2=0.5 w 2=0.6w 2=0.7 w 2=0.8w 2=0.9w 2=1图5.5 丁二酸在甲醇己二酸二甲脂中的溶解度结合图5.3~5.5和表5.1~5.3可以观察出：（1）从图5.3~5.5可以看出，在同一种溶剂配比中己二酸、戊二酸、丁二酸的溶解度随温度的升高而增加；（2）从图5.2、图5.3可以看出己二酸和丁二酸在己二酸二甲脂中的溶解度非常小，随温度升高其增加的幅度很缓慢；混合溶剂中甲醇的质量分数越高，三种溶质的溶解度随温度增长的斜率越大，说明甲醇是敏感因素，Hu, Yong-Hong 认为是由于二元羧酸分子与甲醇分子以非共价键的形式络合，降低了溶剂中分子化学势[48]，因而在甲醇中表现出更易溶。