| Summary: | 碩士 === 龍華科技大學 === 化工與材料工程系碩士班 === 104 === As the time advances, we enjoy the convenience brought by science and technology, but neglect their impact to environment. The petroleum-based polymers are widely used in our daily life, but they can hardly degrade. Moreover, burning such waste can bring toxic gases. In addition to the environment, our health can be badly affected. Therefore, the environment can be less impacted by using biodegradable polymer as a replacement of petroleum-based polymer.
In this study, Polyurethanes (PU) with two kinds of soft segments were synthesized. The soft segments are Polycaprolactone diol (PCL) and Polytrimethylene ether glycol (Bio-PTMG), respectively. The PCL is a chemically synthesized biodegradable polyester, and Bio-PTMG is made from a 100% renewable resource－corn sugar. The FT-IR analysis shows PU were synthesized successfully because all characteristic absorption peaks appeared. The functional groups (-NCO) did not appear, it proves that there remained no H12MDI monomer during the synthesis. Viscosity test shows that the shear viscosity and relative viscosity average molecular weight of the polymer increase as PCL content increases. Thermogravimetric analysis shows PU synthesized with PCL has better thermal stability. Mechanical property tests indicate that the young’s modulus and tensile stress of the sample increase as its PCL content increases; while its tensile strain increases as its Bio-PTMG content increases. Putting PU in phosphate buffered saline (PBS) solution, we find that the rate of weight loss increased with the increase of PCL content, while the pH value has decreased. Observing the surface of PU by microscope, we find that the surface topography of PU was smooth, there were swelling and holes through degradation, some even cracked into small pieces. The experimental data shows that Bio-PTMG and PCL of soft segments can be degradated, and the rate of PU can be regulated by blending different synthesized soft segments into PU. Therefore, it is expected to be applied to various biomaterials in the future.
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