Biodegradable polymers from petroleum

BIODEGRADABLE POLYMERS FROM PETROLEUM-DERIVED PRODUCTS... 

Biodegradable polymers from petroleum sources comprise ... 

The most fundamental classification of polymers is whether they are naturally occurring or synthetic. Common natural polymers (often referred to as biopolymers) include macromolecules such as polysaccharides e.g., starches, sugars, cellulose, gums, etc.), proteins e.g., enzymes), fibers e.g., wool, silk, cotton), polyisoprenes e.g., natural rubber), and nucleic acids e.g., RNA, DNA). The synthesis of biodegradable polymers from natural biopolymer sources is an area of increasing interest, due to dwindling world petroleum supplies and disposal concerns. 

Renewable resource-based polymers Petroleum-based biodegradable polymers Biodegradable polymer from mixed sources (Bio-/petrobased)... 

With the desire to reduce the amount of waste remaining in landfills, there is a need to use biodegradable (sometimes also referred to as compostable) polymers in parts of the world where the infrastructure to capture the gases formed exists. Biodegradable polymers come from either renewable resources or petroleum sources. The primary biodegradable polymers from renewable resources are PLA, PHA, TPS, cellulose, chitin, and proteins. The basic structures of these polymers along with some key thermal characteristics are shown in Table 11.9 and will be discussed in more detail in the following section. 

Biodegradable polymers are polymers that imdergo microbially induced chain scission leading to mineralization. Biodegradable polymers may not been produced from bio-source only, but it can be derived from the petroleum source (Ray and Bousmina, 2005). Efforts... 

Polylactates are an interesting class of biodegradable polymers which may be made from either renewable or petroleum feedstocks. The synthesis of lactic acid raises real issues concerning the relative greenness of the renewable and non-renewable (HCN) route as discussed in Chapter 2. A summary comparison of the greenness of both routes is shown is Table 6.4. Without a full LCA the choice of route on environmental grounds is not easy and at least partly depends on plant location and raw material availability. 

It polymerises to form the polymer, polylactic acid (PLA) which is biodegradable, a Suggest two advantages that PLA has compared with a polymer made from petroleum. [2]... 

In order to decrease human consumption of petroleum, chemists have investigated methods for producing polymers from renewable resources such as biomass. Nature Works polylactic acid (PLA) is a polymer of naturally occurring lactic acid (LA), and LA can be produced from the fermentation of corn. The goal is to eventually manufacture this polymer from waste biomass. Another advantage of PLA is that, unlike most synthetic polymers which litter the landscape and pack landfills, it is biodegradable. PLA can also be easily recycled by conversion back into LA. It can replace many petroleum-based polymers in products such as carpets, bags, cups, and textile fibers. 

Polylactic acid (PLA) is a biodegradable polymer derived from lactic acid. It is a highly versatile material and is made from 100% renewable resources like corn, sugar beet, wheat and other starch-rich products. Polylactic acid exhibits many properties that are equivalent to or better than many petroleum-based plastics, which makes it suitable for a variety of applications. 

Biopolymers and sustainable growth have been recently discussed by Singh (2). "Biopolymers" are defined as polymers made from "renewable" resources. However, not all biopolymers are biodegradable (2). For example, Dow and a Brazilian company called "Crystalsev" announced a joint venture in 2007 to manufacture LLDPE using ethylene produced from ethanol derived from sugarcane (22, 23). Though such LLDPE may be considered a biopolymer, it will not be any more biodegradable than LLDPE from petroleum-based ethylene. 

Sustainability has many definitions. One way to think of it is meeting the needs of the present without compromising the ability of future generations to meet their needs (defined by the World Commission on Environment and Development held by the United Nations in 1983). The concept of sustainability is that we should synchronize our consumption of natural resources with the Earth s production - in other words, using up natural resources at the same rate at which they are produced. Compared to traditional polymers typically made from petroleum and other fossil resources such as natural gas, sustainable polymers are fuUy or partially biobased and/or biodegradable or compostable. They are bioplastics made from renewable resources (biomass) and can be broken down faster than traditional plastics. Sustainable polymers could also protect our Earth by offering a reduced carbon footprint, a reduced use of fossil resources, and improved end-of-life options. 

Back to Nature is the solution then Looking at a few numbers in Table 4.7 may prevent hasty judgments reading this questioa About 50 million t of plastics are produced in Europe each year from petroleum. The production of natural polymers is about 0.1% percent of this total virtually all of which is poly lactic acid. These numbers are not promising it would be lunacy to expect that polylactic acid (Fig. 4.30) or any other semi-synthetic and biodegradable polymer could replace petroleum-based plastics in any foreseeable future. 

Considering the demand and applications of biodegradable polymers, the shortage of landfill availability and petroleum resources and CO2 neutrality, development of polymeric materials from renewable resources has revived research interests around the world. Table 20.1 shows the global projection for materials demand in a business-as-usuar scenario (Chateau et al. 2005 Lysen 2001). It can be understood that the portion of biobased polymeric materials has to be increased according to the projected materials demand and considering the environmental balance. 

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