CASE Coatings, Adhesives, Sealants, and Elastomersfoam and elastic fiber applications all utilize a diverse family of polyols that includes:. Selecting the best polyol for specific formula can be the difference between making a high quality product or a low performance one.
The key for making a proper material selection is a good understanding of the inherent characteristics of each polyol chemistry. PTMEG is the premier polyol used in high-performance polyurethane elastomers. PTMEG-based polyurethanes are known for superior resistance to hydrolytic cleavage, good mechanical properties retention at low temperature, high resiliency, good processing characteristics and excellent mechanical and dynamic properties.
Strain-induced crystallization of the PTMEG soft segments, exact difunctionality and low acid values are all contributing factors to the superior mechanical properties of the associated polyurethane elastomers. This makes PTMEG material of choice for processors specializing in wheels, belts, tires, tubing, abrasion resistant surfaces and many other products. Compared with polyester type polyurethanes, the PPG polyether polyols also exhibit excellent hydrolysis resistance and low temperature properties.
However, compared with the PTMEG and polyester polyols, the PPG polyols have inferior mechanical properties and are more prone to thermo-oxidative degradation. In contrast to PPG polyols, polyester polyols possess better mechanical properties such as tensile and tear strength and flex fatigue resistance. Polyester polyols are reaction products of dicarboxylic acids and diols.
Polyester segments can be crystalline or amorphous.
The polyesters are more resistant to oil, grease, solvents and oxidation. The polycaprolactone polyols exhibit lower melt viscosities, a narrower molecular weight distribution, and low acid values which improve their hydrolytic stability. The polycarbonate polyols are characterized by superior heat and moisture resistance vs. Following is a summary of the attributes of the main classes of polyols to the corresponding urethane elastomers:. Polyether-based polyurethanes exhibit excellent resistance to hydrolysis, even at higher temperatures.
They are the preferred material for applications involving immersion in water or applications that require good property retention in warm and humid environments. Polyesters offer higher initial tensile and tear resistance, but they are susceptible to hydrolytic cleavage. In addition, the presence of residual esterification catalysts can accelerate the hydrolysis. Polycaprolactone polyols and polycarbonate polyols are more hydrolytically stable than standard adipate and phthalate polyesters due to their lower acid levels and a low propensity to generate acid moieties during hydrolysis.
Polyester-based polyurethanes, particularly the semi-crystalline polyol-based polyurethanes, are more resistant to certain types of chemicals. Polyester-based polyurethanes will help your products resist exposure to:.
Polyester Polyols: C.A.S.E.
If resistance to moisture and mild acids and bases is critical, polyether-based polyurethanes are a very good choice. Polyethers have lower glass transition temperature Tg and better retain flexibility and impact resistance at low temperatures.
Polyesters exhibit better thermo-oxidative stability and property retention at elevated temperatures. Polyether-based polyurethanes generally exhibit higher rebound resilience compared to polyester-based polyurethanes. In applications requiring products with higher tensile strength and cut and tear resistance, polyesters are the preferred polyols. Polyethers impart lower hysteresis or heat build-up, which makes them a preferred material for dynamic applications like wheels, casters and rollers.
Abrasion wear is most often a result of the combination of sliding and impingement abrasion. Selecting the right abrasion test, which will most closely correspond with the actual end-use application, can be challenging.
Polyether-based polyurethanes, due to their higher resilience, offer better performance in applications where impingement abrasion is the dominant form of wear.
Although very generalized, it can be said that the higher tensile and tear resistance of the polyester-based polyurethane materials offer an advantage in applications where sliding is the dominant form of abrasion. The environment in which the material is expected to perform must also be considered. A potential for hydrolysis on the surface of the ester-based polyurethanes will negatively impact their long-term abrasion resistance.
PPG polyols are not exact difunctional and contain levels of mono-functionality.Polyester polyols were the first polyols used in the beginning of PU development, and are produced by polycondensation of a diacid with excess diol Figure 1.
Figure 1.Ya ayyuhallazina amanu
Difunctional monomers are used to obtain a linear polymer; and monomers with functionality larger than two as trimethylol propane and glycerin create ramified chains. The most used acids are adipic and phthalics. Adipic acid based polyester polyols are used in applications where flexibility is wanted, as in flexible foams and elastomers. Phthalic acids or phthalic anhydride based polyols, have rigid chains and are used in rigid foams and in high performance coatings Table 1.
Shoe soles. Average MW. Acid number. Then the dicarboxilic acid is added and removal of the reaction water begins. For obtaining the targeted molecular weight the excess diol is calculated by means of Flory Equation.
Diol can be lost during removal of the water form the condensation reaction and through side reactions formation of ethers and aldehydes. The amount of diol lost is dependent upon the processing conditions and upon type of diol. The amount of diol lost must be empirically determined.
Nitrogen, carbon dioxide, or vacuum is used to remove the water and to reach the wanted conversion of This conversion is necessary to minimize the presence of residual carboxylic end groups that can reduce the reactivity.
The polyesters are composed of all possible oligomers raging from the monomers to high molecular weight species: the molecular weight distribution follows a Frory probability. The properties of the PU based polyester elastomers are governed mainly by the overall molecular weight of the polyester and only to a minor degree by the molecular weight distribution. Acids, bases and compounds of the transition metals can catalyze the esterification reaction.
The dicarboxylic acids also exert a limited catalytic effect. In practice catalysts are used reluctantly because they cannot be removed and can have an undesirable effect on the following PU reaction, since inorganic substances even in the smallest quantities favor or retard de PU processing reaction. The p-toluenesulphonic acid can be used as an accelerator and left in the polyester. In cases where small amounts of catalysts do not later cause problems, compounds of tin, antimony, titanium, lead and other metals, have proved especially effective.
The amounts added lie in the ppm range.Polyols process
Solid impurities are removed by hot filtration of the finished polyester. Usually aliphatic polyester polyols used in flexible polyurethanes are based on polyadipates diols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butane diol, 1,6-hexane diol, etc.
The growth of the diol chain results in greater PU flexibility and hydrolytic stability and reduction of polarity and glass transition temperature. Polyester polyols used in PU elastomers Chapter 6based on acid adipic and a glycol like ethylene glycol, 1,4-butane diol, 1,6-hexane diol, neopentyl glycol or mixtures of them Table 1. The crystallinity can be reduced using mixed diols as 1,4-butane diol and ethylene glycol or mixed polyesters.
Lightly branched poly diethyleneglycol adipateswhich are used mainly to make flexible foams, and a wide range of adipates made with more than one aliphatic diol.
These are used to make solid and microcellular elastomers, flexible coatings and adhesives.
Relatively low cost polyester polyols, based on recovery materials are also available. Mixed adipic, glutaric and succinic acid polyesters are made using purified nylon waste acids AGS acids.For the best experience, please use one of the latest browsers. There are two main types of polyurethane: polyester and polyether.Ravelry alternative
Polyester urethane and polyether urethane are elastomers, meaning that they possess elastic properties, and both offer unique performance properties. There are two types of abrasion resistance sliding and impingement.
Sliding refers to scraping and rubbing abrasion while impingement refers to particles or objects striking the urethane surface at a high angle. All elastomers rubbers, urethanes, silicones, etc. Both polyesters and polyethers can be made to any hardness from marshmallow-soft to bowling ball hard.
Products such as skate wheels need to return the energy they absorb when your foot pushes them into the pavement rebound ; otherwise, you would feel like you are running in soft sand. Sand absorbs most of the energy from your foot and makes you run sluggishly. If the product will come in contact with oils, fuel or solvents even vapors your choice should be a. Go to Navigation Go to Content. Your browser is out of date. Jump to: Physical Properties Resistance.
That is why they are the choice for high-speed rollers where the rapid flexing creates heat. Polyether is less affected by cold temperatures. Sometimes you want the product to absorb the energy it receives opposite of rebound. Ask Our Experts. Phone number.Login Register Empty. There are two main classes of polyols used in polyurethanes: polyether polyols and polyester polyols.
Although both polyether polyols and polyester polyols are used in coating, adhesive, sealant and elastomer applications collectively referred to as CASEpolyether polyols are more often used in flexible foam, while polyester polyols are more commonly used in rigid foams. However, depending on the application, the polyols requirement can shift, or even require a mix of both types.
Polyester polyols typically provide superior mechanical properties, such as tensile strength, abrasion, and wear resistance, as well as solvent and oil resistance, to the polyurethanes in which they are used. They represent approximately 20 percent of global polyol demand. The following questions are addressed in the report:. The two reactions used to make polyester polyols are esterification and transesterification, as well as combinations of both reactions. The most common diols are ethylene glycol, diethylene glycol DEGand 1,4 butanediol.
For aliphatic polyester polyols, adipic acid is by far the most frequently employed dicarboxylic acid; while for aromatic polyester polyols, phthalic anhydride and polyethylene terephthalate scrap, such as used PET water bottles, are the most common sources of monomers.
At present, the most fungible and viable bio-polyols are the aliphatic polyester polyols, where biorenewable sources of feedstock monomers such as diacids e. Downstream applications are divided into three categories: rigid foam, flexible foam and coatings, adhesives, sealants and elastomers collectively referred to as CASE. Due to significant regional variations in the demand for rigid foams and CASE made from polyurethanes, regional consumption of the two types of polyester polyols is highly skewed, with Asia Pacific accounting for 59 percent of polyester polyols consumption, including 71 percent of aliphatic polyester polyols.
Due to large local demand, Asia Pacific is the leading supplier of aliphatic polyols, with 65 percent share. In particular, China is the leading supplier of aliphatic polyols, with four of the largest eight aliphatic polyols suppliers based in China. North America and Western Europe account for 69 percent of aromatic polyester polyols capacity, while Asia Pacific and Rest of World are clearly underrepresented, leading to significant imports of aromatic polyols to these regions.
Reports can be purchased as an annual subscription to the full program or on an individual basis, including reports from earlier program years. Major Sustainability Impact via Renewable Power. What can you expect to learn from our online Petrochemical training course? What the Coronavirus could mean for the global petrochemical industry?Abb acs550 fault codes list pdf
Up to date figures. Very interactive and lots of images, videos to make it interesting. Manuel is a wealth of knowledge. The hand-outs are extremely valuable.
The instructor has a talent to turn plain material into a super interesting presentation.Etna Tec Limited, LLC is a high solids, oil-free polyester resin manufacturer for use in formulating industrial coatings. These polyester polyols are used to make high solids, low or zero VOC coatings. These specialty resins may be used in two part urethanes, melamine crosslinked baking systems and BPA free resin systems for can and container coatings. Formulators may also use these polyester polyol resins as modifiers for coil coatings to increase chemical resistance and improve adhesion on poorly prepared substrates.
Our saturated polyesters polyols allow customers to produce coatings with low levels of solvent while retaining superior application and finished coating properties. Call us,for more information. This product is a primary vehicle for container coatings which require FDA SCD offers excellent cure response, coupled with excellent humidity, water and pasteurization resistance. It may be crosslinked with melamines, glycolurils, benzoguanamines and isocyanates.
This polyester polyol resin may also be used for modifying coil and extrusion coatings. SCD has good compatibility with alkyds and acrylics. It improves adhesion, flow, leveling and offers VOC reduction in the final formula. SCD may also be used as a primary vehicle in melamine crosslinked baking systems.
This product is a high solids polyester polyol resin with excellent uncatalyzed cure response and high hardness when used as a primary vehicle in melamine crosslinked baking systems.Utf 7 converter
SCD may also be used to modify coil coatings to improve gloss, mar, corrosion resistance and flexibility. This product meets FDA Both products are excellent resins for direct to metal DTM container applications.
This high solids polyester resin was designed to provide excellent adhesion to both metal and plastic substrates. SCD also exhibits excellent low temperature cure response while maintaining good hardness and flexibility. This product may be used in either melamine or two part urethane coating systems. When used in primer applications, it allows excellent adhesion of either solvent based or water based top coats. Call Today: Call Us: Saturated Polyester Polyol.Polyester polyols are typically produced by the condensation reaction of a glycol with a dicarboxylic acid.
Polyols contain reactive hydroxyl OH groups which react with isocyanate NCO groups on isocyanates to form polyurethane. Polyol polyester provide a better adhesion while improving abrasion resistance and overall hardness.
Polyols for Polyurethanes
Lower hydroxyl values indicates lower hydroxyl content and a higher molecular weight for the overall polyol. Increasing the number of OH groups results in greater crosslinking. Greater crosslinking yields stiffer, harder products with enhanced chemical and thermal resistance.
Polyols that contain 2 hydroxyl groups are called diols, polyols with 3 functional groups are called triols, polyol groups with 4 hydroxyl groups are called tetrols. Teraspartic react with a polyisocyanate to make a high solid resin, two-component polyurethane topcoats and solvent-free coating materials. Polyester Polyols. Request a quotation To request a quotation, please click on the button on the right.
Polyester Polyols Polyester polyols Chemical Structure Composition Production Polyester polyols are typically produced by the condensation reaction of a glycol with a dicarboxylic acid. There are two different types of polyester polyols: Standard polyester polyols are typically quite viscous because of the nature of the reaction between the glycol and the dicarboxylic acid. The molecular weight distribution is relatively broad. Higher performance polyesters such as polycaprolactones are formed by ring opening of a heterocycle ring caprolactone monomer.
The polyol created has a low polydispersity. Polycaprolactones have significantly lower viscosities, enhanced mechanical properties, as well as enhanced low temperature and high temperature performance properties.
Key Parameters: The hydroxyl number OH : is the measure of the hydroxyl group content of gram of polyol. Acrylate polymerization Automotive — Noise, Vibration, Harshness NVH Non-foaming emulsions Fiberglass reinforced backing material Manufactured housing adhesive High quality polyurethane sealants — Sealer insulation one-component foam Polyurethane Elastomers and Thermoplastic Polyurethanes TPU : aliphatic polyesters contribute to excellent abrasion and tear resistance.
They provide as well strong load bearing thus are commonly used in wheels, industrial and printing rolls as well as in mining equipment.Founded inCarpenter Co. The company grew through an unwavering commitment to quality and cost-effective manufacturing processes.Samsung tizen tv
In this way, we challenge ourselves to improve with the goal of being recognized as world class in the markets where we participate. InCarpenter Co. Thus began the production of polyols at our plant in Pasadena, Texas, located on the outskirts of Houston. Approaching its 50 year anniversary, our Roger W. Powell plant has grown to become one of the largest single sites in the world for polyol production and has expanded to produce polyester polyols and specialty alkoxylates for a variety of applications.
Carpenter Co. The Carpenter Co. Chemical Systems Division operates four high-technology chemical blending facilities, located in Texas, Virginia, Indiana, and the United Kingdom, housing chemical blenders and reactors. These locations produce reliable, ready-to-use polyurethane chemical systems for a wide variety of applications.
How can we help you? Contact us to find out more. The chemicals company you can bond with.
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