Biodegradable resins

N-methyl-2-pyrrolidone Biodegradable solvent particularly for resins. 

Film or sheet generally function as supports for other materials, as barriers or covers such as packaging, as insulation, or as materials of constmction. The uses depend on the unique combination of properties of the specific resins or plastic materials chosen. When multilayer films or sheets are made, the product properties can be varied to meet almost any need. Further modification of properties can be achieved by use of such additives or modifiers as plasticizers (qv), antistatic agents (qv), fire retardants, sHp agents, uv and thermal stabilizers, dyes (qv) or pigments (qv), and biodegradable activators. 

Poly(3-hydroxybutyrate—3-hydroxyvalerate) [80181 -31 -3] resin, produced from a bacterium during a sugar fermentation process, has been reported to be biodegradable, and its target markets include "flushables" such as feminine hygiene products and disposable diapers (99). 

Special mention must be made of poly(lactic acid), a biodegradable/bio-resorbable polyester, obtained from renewable resources through fermentation of com starch sugar. This polymer can compete with conventional thermoplastics such as PET for conventional textile fibers or engineering plastics applications. Hie first Dow-Cargill PLA manufacturing facility is scheduled to produce up to 140,000 tons of Nature Works PLA per year beginning in 200245 at an estimated price close to that of other thermoplastic resins U.S. l/kg.46 Other plants are planned to be built in the near future.45... 

Propylene glycol, i.e., 1,2-propanediol (1,2-PDO), is an important commodity chemical. It is used as biodegradable functional fluids and as precursors for the syntheses of unsaturated polyester resins and pharmaceuticals (9-10). Propylene glycol is currently produced from petroleum-derived propylene via oxidation to propylene oxide and subsequent hydrolysis (9, 11). However, the rising cost of propylene provides an incentive to find a substitute to propylene for this... 

As wastewater from resin-producing factories contains recalcitrant compounds, the removal efficiencies achieved by means of the nitrification-denitrification systems could not reach the required disposal values and a posttreatment, such as ozonation, would be necessary to enhance the biodegradability of those compounds.2 53... 

Certain types of adsorption media have been shown to preferentially adsorb certain contaminants. For example, research has shown that, in some cases, coconut shell-based GAC removes MTBE better than typical coal-based GAC. In addition, synthetic resins have been developed to preferentially adsorb some oxygenates, such as TBA, that are less absorbable by GAC. Often, adsorption processes also take advantage of the biodegradability of MTBE and other oxygenates by promoting bacterial growth on the adsorption. 

To avoid this, we have employed hydrophobic resins for concentration and isolation of the products from aqueous media [49]. Organics are retained on the resin and subsequently can be desorbed with solvents such as ethanol, which is useful for green chemistry as it is readily recyclable, renewable and biodegradable. Nonextractive processes offer convenience, can be conducted with high throughput and afford low waste owing to ready disposal of the spent water, recyclability of the resin and the solvent used for desorption. 

Bisphenol A Production of resins (polycarbonate and epoxy resins). Component in flame retardant production Antioxidant, preservative - River water mean values 0.016 pg L 1 (Europe) and 0.5 pg L"1 (US) [66]. -SW <0.001-1 pg U1 [9] - WW effluents mean values 1.5 pg L-1 [67] Not persistent in surface water. Rapidly biodegraded in aquatic environments [68] and removed in WWTP. Half-life 1-4 days [69] in water. Accumulated in anoxic sediments [9]... 

In dentistry, silicones are primarily used as dental-impression materials where chemical- and bioinertness are critical, and, thus, thoroughly evaluated.546 The development of a method for the detection of antibodies to silicones has been reviewed,547 as the search for novel silicone biomaterials continues. Thus, aromatic polyamide-silicone resins have been reviewed as a new class of biomaterials.548 In a short review, the comparison of silicones with their major competitor in biomaterials, polyurethanes, has been conducted.549 But silicones are also used in the modification of polyurethanes and other polymers via co-polymerization, formation of IPNs, blending, or functionalization by grafting, affecting both bulk and surface characteristics of the materials, as discussed in the recent reviews.550-552 A number of papers deal specifically with surface modification of silicones for medical applications, as described in a recent reference.555 The role of silicones in biodegradable polyurethane co-polymers,554 and in other hydrolytically degradable co-polymers,555 was recently studied. 

Other nonfood applications of D-sorbitol result from etherification and polycondensation reactions providing biodegradable polyetherpolyols used for soft pol5mrethane foams and melamine/formaldehyde or phenol resins. Sizable amounts of D-sorbitol also enter into the production of the sorbitan ester surfactants (cf. later in this chapter). 

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