Ester-based TPU

The IIT Series consists of polycaprolactone-based TPU offering outstanding abrasion and wear resistance and a fast set-up in the mold. The IIT series outperforms conventional adipate ester-based TPU in hydrolysis resistance and low temperature flexibility, as well as adhesion strength to other polar plastics, such as ABS, PA, and PVC. 

Seidenstucker X, Fritz H.G., Innovative biodegradable materials based upon starch and thermoplastic poly(ester-urethane) (TPU), Polym. Degrad. Stab., 59,1998, 279-285. 

Figure 10.6 shows the time evolution of dynamic storage modulus G of an injection-molded specimen of ester-based MDI/BDO/PTMA TPU at a fixed angular frequency ( >) of 0.56 rad/s during isothermal annealing for a period of 2 h at 170,... 

Figure 10.9 gives DSC thermograms of specimens of ester-based MDI/BDO/PTMA TPU that were annealed for 1 h in an isothermal chamber at the various temperatures indicated on the DSC thermograms. A fresh specimen was used for annealing at each temperature. The following observations are worth noting in Figure 10.9. The specimen...

Figure 10.9 Effect of annealing temperature on thermal transitions, as determined by DSC, in ester-based MDI/BDO/PTMA TPU specimens that have been aimealed for 1 h at the predetermined temperatures indicated on the DSC thermograms. DSC runs were made at a heating rate of 20 C/min, and an as-received specimen was used for each DSC run. (Reprinted from Yoon and Han, Macmmolecules 33 2171. Copyright 2000, with permission from the American Chemical Society.)...

Table 10.2 Effect of annealing temperature on the molecular weight of an ester-based MDI/BDO/PTMA TPU...

Figure 10.14 Variations of the A, /Af ratio for the N-H stretching absorption bands in the KllK spectra with time during isothermal annealing at 170 °C (a) ester-based MDI/BDO/PTMA TPU specimens prepared by injection molding at 180 °C (O) and 220 (A) and (b) ether-based...

Figure 10.15 Plots of (a) logG versus log co and (b) log G" versus log co for an ester-based MDI/BDO/PTMA TPU specimen during frequency sweep experiments in the heating cycle at various temperatures CC) (O) 110, (A) 120, ( ) 130, (V) 140, (O) 145, (O) 150, ( ) 155, (A) 160, ( ) 170, (T) 180, and ( ) 190. A single specimen prepared by injection molding at 180 °C was employed for the entire experiment. (Reprinted from Yoon, Doctoral Dissertation at the University of Akron. Copyright 2000, with permission from PU Joong Yoon.)...

The most important examples of thermoplastic elastomers include TPE-0 (polyolefin-based TPE), TPE-A (polyether(ester)-block-amide), TPE-E (copolyester-based TPE), TPE-S (styrene copolymer-based TPE), and TPU (polyurethane-based TPE). 

Polyadipates, polycarbonate diols, and polyethers based on long-chain diols as components of the TPU molecule result in higher hydrolysis resistance. Esters with hydrophobic diol and an acid with low dissociation constant are especially well protected against the influence of hydrolysis. Long-chain diols are thus more hydrolysis resistant than short-chain diols [86]. 

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