## 3 Results and Discussion
However, regardless of the type of butanediol used, the thermal degradation spectra of the TPUs are similar. The use of 1,3-BDO as the chain extender did not greatly affect the polymer structure, indicating that the polymerized TPUs have excellent thermal stability. The thermal conversion effect was evaluated using DSC. The thermal properties of the TPUs are presented in Figure 3, which clearly illustrates that the TPUs synthesized using 1,3-BDO have no temperature for melting (T\({}_{\text{m}}\)). For TPUs synthesized using 1,4-BD, their T\({}_{\text{m}}\) range is between 139 \({}^{\circ}\)C and 150 \({}^{\circ}\)C; this is common for TPUs. The TPUs synthesized using 1,3-BDO also have no melting point; this indicates that their structures are not crystalline, and this is related to the fact that they possess some viscosity. Figure 2: Thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) spectra of TPU prepared through the polymerization of PBA (**a**), PTMG (**b**), or PCDL (**c**), with 1,3-BDO or 1,4-BDO. When 1,3-BDO was used as the chain extender in synthesizing TPU, the glass transition temperature (T\({}_{\rm g}\)) was higher than when synthesis was performed with 1,4-BDO. When two types of polyol, namely PBA or PTMG, are used in synthesizing TPU, the T\({}_{\rm g}\) of TPU synthesized using 1,3-BDO was approximately 10-15 \({}^{\circ}\)C higher than the T\({}_{\rm g}\) of TPU synthesized using 1,4-BDO. When PCDL was used to synthesize TPU, the T\({}_{\rm g}\) of the TPU synthesized using 1,3-BDO was approximately 5 \({}^{\circ}\)C higher than that of the TPU synthesized using 1,4-BDO. The results also revealed the T\({}_{\rm g}\) of TPU synthesized from PCDL and 1,3-BDO was approximately 15 \({}^{\circ}\)C; this temperature is close to room temperature (15-25 \({}^{\circ}\)C) [28,61]. This indicates that the TPU could be used as a novel type of composite material produced through high polymer processing at room temperature (20 \({}^{\circ}\)C) [16]. The researchers compared the major mechanical characteristics (storage modulus (G\({}^{\prime}\)), loss modulus (G\({}^{\prime\prime}\)), and tan \(\delta\)) using DMA. According to the data (Figure 4), the tan \(\delta\) values of TPU synthesized using 1,3-BDO are higher than the tan \(\delta\) values of TPU synthesized using 1,4-BDO. This confirms that when 1,3-BDO was used for the synthesis, the appearance of the resultant TPU was soft and viscous. Based on the storage modulus diagram, the storage modulus of TPU synthesized using 1,4-BDO would be significantly  
Figure 3: Differential scanning calorimetry (DSC) thermograms of TPU formed through the polymerization of PBA (**a**), PTMG (**b**), or PCDL (**c**), with 1,3-BDO or 1,4-BDO. reduced under lower temperature than TPU synthesized using 1,3-BDO; this is probably related to their lower \(\rm T_{g}\). Figure 4: According to dynamic mechanical analysis (DMA), the following parameters were measured: storage modulus (mPa) and tan \(\rm\delta\) related to the temperature rate; storage modulus (**a**) and tan \(\rm\delta\) (**b**) of TPU from PBA, storage modulus (**c**) and tan \(\rm\delta\) (**d**) of TPU from PTMG; storage modulus (**e**) and tan \(\rm\delta\) (**f**) of TPU from PCDL. All the glass transition point (T\({}_{\text{g}}\)) data obtained through DMA analysis are listed in Table 4. The T\({}_{\text{g}}\) of TPU synthesized using 1,3-BDO was approximately 10-15 \({}^{\circ}\)C higher than the T\({}_{\text{g}}\) of TPU synthesized using 1,4-BDO. The reason behind this is that 1,3-BDO contains a methyl group in its structure, and this results in an asymmetrical TPU structure during the polymerization process. The DMA results also confirmed that TPU synthesized using 1,3-BDO has viscoelasticity (this must correspond with the conclusion from the DSC scan, which tends to be viscous materials). The storage modulus (G\({}^{\prime}\)) data confirmed that TPUs synthesized using 1,3-BDO have greater viscoelasticity than TPUs synthesized using 1,4-BDO.