Outdoor performance

Strontium. Strontium 2-ethyIhexanoate [2457-02-5] is a candidate to replace lead in lead-free paints. It functions well under adverse weather conditions and promotes through drying. Outdoor performance of low pigmented coatings like stains may be effected negatively by using strontium instead of zirconium. 

PVC is accepted commercially as an excellent weathering material. PVC s chemical response to weathering is well understood so that compounds and products can be designed for satisfactory outdoor performance. Products include siding, windows, and doors. 

Room temperature curing, two-part epoxy adhesives are usually considered to have a lower level of outdoor performance than the heat cured adhesives. Their performance, however, can be improved by heat treatment following the room temperature cure. 

One of the more recent studies on cotton, polyester, and nylon (24) demonstrated that cotton was superior to the synthetics in outdoor performance in areas of low air pollution but that its performance was reduced considerably in areas of high air pollution. Specific effects of air pollutants are discussed later under chemical agents causing fiber degradation. 

Acetal translucent crystalline polymer is one of the stiffest TPs available. It provides excellent hardness and heat resistance, even in the presence of solvents and alkalies. Its low moisture sensitivity and good electrical properties permit direct competition with die-cast metal in a variety of applications. In addition, acetal has extremely high creep resistance and low permeability. Acetal is also available as a copolymer (Hoechst Celanese Corp. s Celcon) for improved processability. The homopolymer (DuPont s Delrin) has a very low coefficient of friction and its resistance to abrasion is second only to nylon 6/6. Acetals are frequently blended with fibers such as glass or fluorocarbon to enhance stiffness and friction properties. Acetal is not particularly weather-resistant, but grades are available with UV stabilizers for improved outdoor performance. Acetal, whether homopolymer or copolymer, is not used to any significant degree in forming structural foams. 

Understanding the role of chemical modification of wood and wood surface in controlling the outdoor weathering process is significant to the future use of wood exposed to the outdoors. The role of modification will become larger as greater demands are placed on the newer wood-based products. The future of such modification lies in end-product property enhancement. Permanently bonded chemicals that provide UV stabilization, color control, water resistance, and dimensional stability could enhance outdoor performance greatly. 

From the above work our data suggests that the PIR values calculated for different chemistries do correspond to the natural weatherability of the polymer systems. This would have to be confirmed with more extensive studies with chemistries that have UV durability performance closer together. However, in the case of polymeric blends the PIR values show poor correlation with the known outdoor performance and this is always likely to be the case where the blends produce complex heterogeneous morphologies. 

Better hygroscopic behavior of boards (e.g., lower thickness swelling, higher resistance against the influence of humidity and water, better outdoor performance)... 

Potential adverse effects affect color, affect outdoor performance, affect toxicity of products, decrease chemical resistance, decrease flame resistance, decrease fog resistance, decrease stain resistance, increase coefficient of friction, increase gas permeability, increase porosity, increase price, increase smoke generation, increase snrface tack, lower scratch resistance, lower tensile strength modulus, lower wear resistance... 

Nyoni, A.B., Brook, D., 2010. The effect of cyclic loading on the wicking performance of nylon 6.6 yams and woven fabrics used for outdoor performance clothing. Text. Res. J. 80, 720-725. 

Resins vary a great deal in their ability to withstand outdoor use for long periods. Those with poor outdoor performance can sometimes be completely transformed by trace additives, so the problem becomes one of using... 

Studies of the effect of plasticizers on PVC film stability were conducted using samples cast from tetrahydrofuran, THF. Samples which contained THF degraded more rapidly which is well known in weathering studies. THF exposed to UV radiation forms radicals which accelerate thermal degradation of PVC. Based on this example, it shonldbe also noted that plasticizer performance in any other aspect than weathering is not affected by admixtures but admixtures may be very critical for the outdoor performance of maity products. It is thus important to check the source and quality of the plasticizer. 

The lifetime of the greenhouse cover films used outdoor depends mainly on a number of factors. Table 5.3 presents the factors responsible for the outdoor performance of greenhouse films and the details of these factors. 

As noted in Section 6.5.2, the hydrolysis resistance of latex films from emulsion polymers prepared from the vinyl acetate (VA) monomer is marginal for ontdoor use. In Europe and recently in the United States, vinyl versatate (II) (Ri = —CH2CH2CH2CH2CH2CH2CH3 and R2 = R3 = —CH3) has been introduced for use along with vinyl acetate for improved outdoor performance of latex coatings. Vinyl versatate is the vinyl ester of versatic acid, a 10-carbon carboxylic acid of the highly branched structure sometimes called neo ... 

Clabburn R.J.T., Pennech R.J. and Swinmurn, The Outdoor Performance of Plastics Materials used as Cable Accessories, Paper presented at lEE Power Engineering Society, New York, Jan-Feb. 1973. 

Keywords photooxidation, UV absorbers (UVA), outdoor performance, weathering, accelerated weathering, kinetic chain length, photoinitiator, Norrish reactions, peroxide decomposer, hindered amine light stabilizers (HALS), photosensitizer, transition metal complex, UV stabilizer, time-controlled stabilization, reactive antioxidants, polymeric antioxidants. 

Mople SP Himont PP TPO proven good outdoor performance, especially caibon blade and UV stabilizer containing... 

Many polymers which are intrinsically transparent to the shorter wavelengths of the sun s spectrum (<290 nm), become sensitized by the presence of light absorbing impurities and trace level of metals and adventitious species produced during manufacture and fabrication. Hence the susceptibility of commercial polymers (e.g. PE and PP) to outdoor weathering. The outdoor performance of polymers can, however, be markedly improved by photoantioxidants and UV-stabilizers. 

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