Weathering stability

A xenon arc test of fading resistance also demonstrated that PLA fibers perform better than PET fibers, with a 0% loss in elongation at break for the PLA fibers and a 30% loss in elongation at break for the PET fibers, after lOOh of xenon arc exposure [4]. The superior resistance to exposure to daylight with rainfall and UV is an attractive feature that brings promise for potential outdoor applications such as in agricultural, horticultural, geotextile, and industrial areas. 

FIGURE 29.10 Test results for flammability of the fabrics of PLA and PET in accordance with the Federal Safety Standards for Vehicles FMVSS 302. 

FIGURE 29.11 Accelerated weathering test result of PLA and PET fibers by Sunshine Weather Meter. 

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In the early 1960s other terephthalates became available, particularly poly-(1,4-cyclohexylene terephthalate) Figure 21.10 (b)), with slightly higher and superior water and weathering stability to poly(ethylene terephthalate). Fibre and film forms became available. 

This polymer has a slightly stiffer chain and hence slightly higher melting point and heat distortion temperatures than poly(ethylene terephthalate). Films are available (Kodel-Kodak) which have been biaxially stretched about 200% from polymer with molecular weights of about 25 000. They are similar electrically to poly(ethylene terephthalate), are weaker mechanically but have superior resistance to water and in weathering stability. Some properties are given in Table 25.6. 

Quality, magnitude, and duraUon of the release Dispersion parameters -Wind speed -Wind direction -Weather stability... 

Dispersion parameters (wind speed, wind direction, weather stability)... 

Table 51 shows an overview of pigments with luster effects. Effect pigments can be classified as metal platelets, oxide-coated metal platelets, oxide-coated mica platelets, platelet-like mono-crystals and comminuted PVD-films (Physical Vapor Deposition). Aims of new developments are new effects, colors, improvement of hiding power, increase of the interference color, increase of light and weather stability and improved dispersibility characteristics. Of special interest are pigments which are toxicologically safe and which can be produced by ecologically acceptable processes. 

Almond Prunus dulcis, P. amygdalis, Amygdalis communis). Almond oil is generally considered as an oleic-rich oil (65-70%), but its fatty acid composition can vary widely. The triacylglycerol composition of the oil has also been reported. Low-saturated, high-monounsamrated oils show high oxidative and cold weather stability (i.e., they are slow to deposit crystals) (65, 66). 

Apricot Prunus armeniaca). Apricot seed oil is used in cosmetics and is available as a speciality oil for food use. It contains oleic (58-74%) and Unoleic acids (20-34%). One study gives values of palmitic 5%, stearic 1%, oleic 66%, and lino-leic acid 29%. With its low content of saturated acids, it shows excellent cold weather stability (71, 72). The fatty acid composition of the phospholipids has been reported (73). 

Organosilicon Compounds for Stone Impregnation -Long-Term Effectivity and Weathering Stability... 

Tn the construction materials colorant sector, the chemical stability, light fastness and weathering stability of synthetic iron oxide pigments are important. Concrete bricks, paving stones, roofing tiles, asbestos cement, mortar, bitumen and facade plaster are all currently colored with iron oxide pigments. 

WEATHERING STABILITY Zircon, tourmaline, rutile-----ultrasta... 

Use Imparts flame resistance, good low temperature properties, light and weathering stability, and stability in vinyls. 

Limiting the diffusion of oxygen improves the weather stability of materials due to reduced photooxidation. " This subject is discussed in Chapter 11. 

Polyhydroxyurethane polymer usually has poor water resistance due to plurality of hydroxyl groups, but it is possible to prepare water-resistant materials in some formulations. For example, a cyclocarbonate acrylic was applied on a base of acrylic epoxy oligomer and a polymer was prepared with high water and weather stabilities... 

Material Specific gravity (density) (g/cm ) Elexural properties Strength, psi Modulus, psi Compressive strength (psi) Water absorption after 24 h (%) Coefficient of thermal expansion-contraction, X 10-5 Weather stability... 

Elvax 150 softens to a viscous melt above 70°C, and therefore Is not suitable for temperature service above 70°C when employed In a fabricated module. A cure system was developed for Elvax 150 that results In a temperature-stable elastomer ( ). Elvax 150 was also compounded with an antioxidant and UV stabilizers, which Improved Its weather stability and did not affect Its transparency. The formulation of the encapsulation grade ethylene vinyl acetate Is given In Table I. These Ingredients are compounded Into Elvax... 

Reasons for use compatibility, low transfer to material in contact, low volatility, oxidation and thermal stability, reduced coefficient of friction, reduced surface tack, weather stability... 

Chetn. Descrip. Epoxidized soybean oil CAS 8013-07-8 EINECS/ELINCS 232-391-0 Uses Stabilizer and plasticizer for all PVC formulations, film and sheet for agric., transparent food pkg., cable, gasket, hose, tube, paint stabilizer for org. halogen such as neoprene Features Provides exc. heat and weathering stability rec. for improving heat stability in Ba-Zn or Ca-Zn formulation Regulatory FDA and JHPA compliance... 

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