Petro-based polymers

Over the past several decades, polylactide - i.e. poly(lactic acid) (PLA) - and its copolymers have attracted significant attention in environmental, biomedical, and pharmaceutical applications as well as alternatives to petro-based polymers [1-18], Plant-derived carbohydrates such as glucose, which is derived from corn, are most frequently used as raw materials of PLA. Among their applications as alternatives to petro-based polymers, packaging applications are the primary ones. Poly(lactic acid)s can be synthesized either by direct polycondensation of lactic acid (lUPAC name 2-hydroxypropanoic acid) or by ring-opening polymerization (ROP) of lactide (LA) (lUPAC name 3,6-dimethyl-l,4-dioxane-2,5-dione). Lactic acid is optically active and has two enantiomeric forms, that is, L- and D- (S- and R-). Lactide is a cyclic dimer of lactic acid that has three possible stereoisomers (i) L-lactide (LLA), which is composed of two L-lactic acids, (ii) D-lactide (DLA), which is composed of two D-lactic acids, and (iii) meso-lactide (MLA), which is composed of an L-lactic acid and a D-lactic acid. Due to the two enantiomeric forms of lactic acids, their homopolymers are stereoisomeric and their crystallizability, physical properties, and processability depend on their tacticity, optical purity, and molecular weight the latter two are dominant factors. 

Poly(L-lactic acid) is an effective alternative to petro-based polymers in applications such as packaging material, automotive materials, including floor mats and spare tire covers, and the chassis of electrical appliances such as computers, mobile phones, remote controls, and optical disks [422,423]. Figure 8.26 shows the commodity applications of PLLA. For... 

Polymerization of Bionolle 3001 (polybutylene succinate/adipate) using bio-based and petro-based succinic acid was examined. As for polymerization conditions and processability, there was no significant difference between these two types of resin. Mechanical properties of blown films processed from both resins were almost the same. The quality of bio-based succinic acid turned out to be good enough as a polymer grade. 

As is the case for biobased polyolefins, the production of the polymer from the biobased monomer is identical to production of petro-based PET, and the resulting properties are identical (except for the ratio of carbon isotopes, as discussed above). Several routes to terephthalic acid are currently under consideration. They include routes through isobutanol, para-xylene, and muconic acid, derived from various plant sources. 

Figure 10,2 Cost vs. performance pyramid of petro-based and bio-based polymers.

Bio does not necessarily have to denote low quality or inferior let alone biodegradable. As mentioned in section 10.2.1, polyamides are true high performance polymers, yet seeing that only 5% of the current biopolymer market is served by PA-types it may take a while to modify the public perception and association. In this respect, the title of this chapter has been well chosen. Furthermore, several of the main bio-based polyamide producers have opted to use the trade names originally deemed for their main petro-based polyamides to uphold the notion of high performance, for example Arkema with Rilsan or Evonik with Vestamid (see Table 10.2). 

Surfactants used as lubricants are added to polymer resins to improve the flow characteristics of the plastic during processing they also stabilise the cells of polyurethane foams during the foaming process. Surfactants are either nonionic (e.g. fatty amides and alcohols), cationic, anionic (dominating class e.g. alkylbenzene sulfonates), zwitterionic, hetero-element or polymeric (e.g. EO-PO block copolymers). Fluorinated anionic surfactants or super surfactants enable a variety of surfaces normally regarded as difficult to wet. These include PE and PP any product required to wet the surface of these polymers will benefit from inclusion of fluorosurfactants. Surfactants are frequently multicomponent formulations, based on petro- or oleochemicals. 

Catalysis refers to the phenomenon by which the rate of a chemical reaction is accelerated by a snbstance (the catalyst) not appreciably consnmed in the process. The term catalysis was coined by Berzelins in 1835 and scientifically defined by Ostwald in 1895, but applications based on catalysis can be traced back to thousands of years ago with the discovery of fermentation to produce wine and beer. Nowadays, catalysts are used in 80% of all chemical industrial processes, and create annual global sales of about 1500 billion dollars and contribute directly or indirectly to approximately 35% of the world s GDP. Catalysis is central to a myriad of applications, including the manufacture of commodity, fine, specialty, petro-, and agro- chemicals as well as the production of pharmaceuticals, cosmetics, foods, and polymers. Catalysis is also an important component in new processes for the generation of clean energy, and in the protection of the enviromnent both by abating environmental pollutants and by providing alternative cleaner chemical synthetic procedures. 

I make no attempt here to evaluate the success or failure of its moves into these different specialty chemicals, but clearly the company prospered. Solvay enjoyed the option of moving into these new sectors because it employed the capabilities learned from the initial commercializing of the Solvay process to commercialize products early in the century in electrolytically based inorganic chemicals. It then succeeded in entering polymer/petro-chemicals in the same manner as did the German Big Three, particularly Hoechst. 

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