Aliphatic Saturated Polyesters

Relationship Between Tm and the Biodegradability of Polyester by Lipases. The relationship between Tm and the biodegradability of saturated aliphatic polyester is shown in Figure 6. For the same series polyesters, the biodegradabilities decreased with increasing Tm. 

With the exception of poly (ethylene oxalate) [poly(ethylene glycol oxalate)], saturated aliphatic polyesters have a relatively low melting point because of the low energy barrier to rotation (see Section 4.2). For example, poly(ethylene adipate) melts at 54°C. 

Hydroxyl number, acid number, and moisture in saturated aliphatic polyesters can be simultaneously determined using NIR. 

Use of saturated aliphatic polyesters containing 1.4 3.6-dianhydro-sorbitol moieties as plasticizers of PVC [268]. 

Polylactacide (4.54) is a saturated aliphatic polyester which is susceptible to photo-degradation [1449]. The main reaction is a chain scission by the Norrish Type I reaction with the formation of COj and HjO ... 

Polyester Polyols. Polyester polyols are based on saturated aliphatic or aromatic carboxylic acids and diols oi mixtures of diols. The carboxylic add of choice is adipic acid because of its favorable cost/performance ratio. For elastomers, linear polyester polyols of ca 2000 mol wt are preferred. Branched polyester polyols, formulated from higher functional glycols, are used for foam and coatings applications. Phthalates and terephthalates are also used. 

PVC can be blended with numerous other polymers to give it better processability and impact resistance. For the manufacture of food contact materials the following polymerizates and/or polymer mixtures from polymers manufactured from the above mentioned starting materials can be used Chlorinated polyolefins blends of styrene and graft copolymers and mixtures of polystyrene with polymerisate blends butadiene-acrylonitrile-copolymer blends (hard rubber) blends of ethylene and propylene, butylene, vinyl ester, and unsaturated aliphatic acids as well as salts and esters plasticizerfrec blends of methacrylic acid esters and acrylic acid esters with monofunctional saturated alcohols (Ci-C18) as well as blends of the esters of methacrylic acid butadiene and styrene as well as polymer blends of acrylic acid butyl ester and vinylpyrrolidone polyurethane manufactured from 1,6-hexamethylene diisocyanate, 1.4-butandiol and aliphatic polyesters from adipic acid and glycols. 

The octane number of the gasoline fraction composed of the aliphatic polyester fragments could be predicted by taking into account the linear and cyclic oxygenated saturated hydrocarbon nature of the components. 

In order to achieve lower gelation doses for saturated linear aliphatic polyesters such as polycaprolactone, certain functional groups including unsaturation can be incorporated. In this regard, and as will be discussed here, e-caprolactone has been copolymerized with a relatively small amount of allyl glycidyl ether. Therefore, the randomly distributed allyl glycidyl ether units(2-6 mole percent) in the synthesized caprolactone-allyl... 

Saturated paint polyester resins are soluble in esters, ketones, and in some cases aromatic hydrocarbons, but are insoluble in aliphatic hydrocarbons and alcohols. Solvent-containing paints based on high molecular mass resins have solids contents of 35-50 wt% at application viscosity. Paint solids contents for low molecular mass polyesters are 50-70 wt%. 

Unsaturated polyesters are produced in the form of dissolved resins in polymerizable monomers (usually styrene). They are also known in the form of molding resins or as hardened products. One should distinguish between them and the saturated aliphatic and aromatic polyesters. Among the latter are polyethylene terephthalate and polybutylene terephthalate. 

The specialty class of polyols includes poly(butadiene) and polycarbonate polyols. The poly(butadiene) polyols most commonly used in urethane adhesives have functionalities from 1.8 to 2.3 and contain the three isomers (x, y and z) shown in Table 2. Newer variants of poly(butadiene) polyols include a 90% 1,2 product, as well as hydrogenated versions, which produce a saturated hydrocarbon chain [28]. Poly(butadiene) polyols have an all-hydrocarbon backbone, producing a relatively low surface energy material, outstanding moisture resistance, and low vapor transmission values. Aromatic polycarbonate polyols are solids at room temperature. Aliphatic polycarbonate polyols are viscous liquids and are used to obtain adhesion to polar substrates, yet these polyols have better hydrolysis properties than do most polyesters. 

The best performing coatings were the vinyl ester, the bisphenol A epoxy cured with an aliphatic amine, and a novolac epoxy cured with a mixed aromatic/cycl oal i phati c amine. The saturated polyester, and a bisphenol A epoxy cured with a polyamide amine showed significant deterioration of the coating material in the acid, and corrosion of the underlying steel. Two types of novolac epoxies cured with aromatic amines showed intermediate performance. 

The fuel properties of the pyrolysis oil of an aliphatic polyether-segmented PU could be predicted by taking into account the linear and cyclic oxygenated saturated and olefinic hydrocarbon nature of the components. Elimination of the reactive and toxic diisocyanate from the pyrolysis oil of PU in a lower temperature pyrolysis step is easier in the case of polyether soft segment, because of the larger temperature difference of decomposition steps compared to that of polyester-segmented PU. 

Water absorption is less in the case of cured polyesters containing aromatic acids, compared with those containing aliphatic saturated acids. Factors that contribute towards the flexibility of cured polyesters also tend to promote water absorption. The water sensitivity of cured resins also depends on the relative amounts of terminal hydroxyl and terminal carboxyl groups. 

The type of acid present in the polyester influences the compressive strength. Polyesters based on aliphatic saturated acids have a low compressive strength. 

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