Chemistry Reference
In-Depth Information
evolving, currently the top five bio-plastics in 2010 based on production
were: bio-based polyethylene (bio-PE), bio-degradable starch blends, poly-
lactic acid (PLA), polyhydroxyalkanoate (PHA), and bio-degradable poly-
esters.
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By 2015, starch blends will be replaced by bio-based polyethylene
terephthalate (bio-PET). Unfortunately, both bio-PE and bio-PET are not bio-
degradable or compostable. Factors that hinder the growth of the bio-plastic
industry include: confusing terminology (i.e., not all bio-based plastics are
bio-degradable); lack of infrastructure to develop or reprocess bio-plastics
(i.e., slow acceptance for food waste diversion programs and lack of adequate
composting and industrial bio-degradation infrastructure); lack of funding
to develop new bio-plastics (i.e., few public offerings as well as few govern-
mental grants); and finally and most importantly, the limited availability of
bio-based feedstocks to manufacture bio-plastics (i.e., the bio-based chem-
ical supplies are limited and their costs are high).
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Nevertheless, bio-plastics are expected to increase in use by 40% from
2010 to 2015.
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Factors promoting the use of bio-plastics include: the un-
certain and fluctuating cost of petroleum prices; regulatory and legislative
actions aimed at the reduction of plastic waste in order to minimize its
detrimental environmental effects; and the productive utilization of bypro-
ducts generated from the food and agricultural processing industries as
feedstock materials.
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Undoubtedly, the most significant reason for re-
placement of petroleum-based plastics with bio-based plastics is the in-
creasing evidence that petroleum plastics may be responsible for a myriad of
health and environmental problems.
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Consumer acknowledgement of the
environmental problems associated with petroleum-based plastics was
clearly recognized in the 2011 Cone/Echo Global Corporate Responsibility
Survey where 94% of the respondents indicated that they buy ''green''
products over ''non-green'' products.
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7.2 Alternative Bio-plastics and their Potential Uses
7.2.1 Epoxidized Vegetable Oil Polymers
Vegetable oils that have high contents of unsaturated fatty acids can be
converted into epoxy fatty acids by conventional epoxidation, catalytic acidic
ion-exchange resins, catalyst epoxidation, or by using chemo-enzymatic
epoxidation.
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Epoxidized vegetable oils (EVOs) can be used as a raw
material for the synthesis of several chemicals including alcohols (polyols),
glycols, olefinic compounds, lubricants, plasticizers, and stabilizers for
polymers.
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The most common EVOs are derived from oil palms and soy-
bean due to their high cultivation acreage. EVOs may also be potential re-
placements for petroleum-based epoxy, polyester and vinyl esters since they
are obtained from renewable feedstocks, pose fewer environmental health
risks in their utilization, and are bio-degradable. The use of EVOs, especially
epoxidized soybean oil (ESBO), in the production of stable polyesters has
been well documented over the last 25 years.
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