Enthalpy-Entropy Compensation in Polyester Degradation Reactions
Table 1
Kinetic characteristics of different polyesters.
PBT-N2
PTT-N2
PET-N2
β
β
β
Zone 1
5
648
270
−0.015
275
265
5
673
439
−0.022
448
433
5
695
483
−0.169
594
477
10
669
278
−0.011
280
273
10
693
450
−0.022
458
444
10
710
494
−0.148
593
488
15
674
295
−0.005
292
289
15
718
429
−0.025
441
423
15
717
480
−0.174
599
474
20
682
281
−0.010
283
276
20
726
429
−0.025
441
423
20
725
475
−0.182
601
469
Zone 2
5
771
253
−0.016
258
246
5
799
310
−0.027
326
304
5
901
459
−0.031
480
452
10
793
273
−0.012
276
266
10
822
370
−0.022
381
363
10
972
470
−0.029
490
462
15
800
295
−0.008
294
288
15
834
379
−0.021
389
372
15
949
443
−0.036
470
435
20
807
266
−0.013
270
259
20
848
290
−0.031
309
283
20
973
430
−0.042
463
422
PBT-AIR
PTT-AIR
PET-AIR
β
β
β
Zone 1
5
652
304
−0.031
318
298
5
657
328
−0.045
352
323
5
701
397
−0.168
509
391
10
663
390
−0.015
395
385
10
671
397
−0.033
413
391
10
706
463
−0.151
564
457
15
670
382
−0.017
388
376
15
679
411
−0.030
426
405
15
719
446
−0.157
552
440
20
676
407
−0.012
410
402
20
686
389
−0.037
408
383
20
725
402
−0.167
517
396
Zone 2
5
767
184
−0.036
205
178
5
763
274
−0.040
298
268
5
901
309
−0.029
328
302
10
790
207
−0.021
216
200
10
787
300
−0.036
321
293
10
905
391
−0.019
401
383
15
805
196
−0.027
212
190
15
803
296
−0.036
318
289
15
928
432
−0.013
436
424
20
808
179
−0.042
205
172
20
823
280
−0.039
305
273
20
950
382
−0.021
393
374
β: heating rate (°C/min), : peak degradation temperature (°C), : activation energy (kJ/mol), : change in entropy (kJ/mol), : change in free energy (kJ/mol), : change in enthalpy (kJ/mol).