Terephtahlic acid

As shown in Figure 14.4, there are two bio-based carbon atoms and eight fossil carbon atoms per PET molecule, which means a 20% bio-based carbon content. On a mass basis, there are 31.25% bio-based glycol components and 68.75% fossil terephthalic acid components in the polymer. From a material carbon footprint perspective the CO2 arising from the glycol s two carbon atoms would have a zero carbon emissions impact, and only the eight fossil carbon atoms from the terephtahlic acid component would contribute to the carbon emissions impact. 

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