What are polymeric polyols?
Polymer polyols are defined as very fine and stable dispersions of solid polymers (vinylic polymers and copolymers, polyurea, polyurethanes) in liquid polyethers. Currently polymer polyols represent one of the most important group of polyolic intermediates for elastic polyurethanes [1-10].
What is polyols used for?
Polyols are reacted with diisocyanates to produce polyurethanes. Polyurethanes are used to make flexible foam for mattresses and seating, rigid foam insulation for refrigerators and freezers, elastomeric shoe soles, fibers (e.g. Spandex), coatings, sealants and adhesives.
What is polyether triol?
Polyether triols are formed by propoxylating an initiator (addition of propylene oxide to an initiator). In some cases, the initiator is ethoxylated (addition of ethylene oxide) as well as propoxylated. Ethoxylation can be incorporated in the middle of the polyol, or at the end (tip) of the triol.
How are polyols made?
Polyols can be either polyether polyols or polyester polyols. Polyether polyols are made by the reaction of epoxides with compounds having active hydrogen atom. Polyester polyols are made by the polycondensation reaction of multifunctional carboxylic acids and polyhydroxyl compounds.
What is NCO chemical?
NCO – an isocyanate chemical group. This designation refers to the nitrogen, carbon, and oxygen atom of the isocyanate group. %NCO – a measure of the isocyanate content of a prepolymer or other isocyanate-containing compound measured as the weight percent of unreacted isocyanate groups in the material.
Do polyols cause weight gain?
With the exception of erythritol, polyols still contain some calories, so consuming large amounts of them can still lead to excess calories (as well as possible gut issues, as described above). That said, one small change in your diet will rarely make a big difference in your weight.
How do polyols affect the body?
Polyols can induce dose-dependent gastrointestinal symptoms of flatulence, bloating, abdominal discomfort, and laxative effects when consumed in healthy volunteers and patients with IBS.
Is polyurethane toxic to humans?
Polyurethane is the result of the chemical reaction between a polyol and a diisocyanate. Once the chemical reaction of its components has taken place, the result is a polyurethane foam that is completely inert and harmless to humans.
How are polyether polyols made?
Polyether polyols are made by the reaction of epoxides with compounds having active hydrogen atom. Polyester polyols are made by the polycondensation reaction of multifunctional carboxylic acids and polyhydroxyl compounds. They can be further categorized according to their end use.
What is the meaning of polyether?
Definition of polyether : any of a group of polymers in which the repeating unit contains a carbon-oxygen bond derived especially from an aldehyde or an epoxide and which are used especially in the manufacture of plastic foams.
Is polyols natural?
Polyols are a specific group of sugar alcohols that are formed via the catalytic hydrogenation of carbohydrates. They are found naturally in certain fruits, vegetables, and mushrooms; however, they are also commonly used as sugar-free sweeteners in products such as chewing gum, candies, and beverages.
Are polyols good for you?
Although polyols are not essential nutrients, they contribute to clinically recognised maintenance of a healthy colonic environment and function. A role for polyols and polyol foods to hydrate the colonic contents and aid laxation is now recognised by physicians.
What makes polycaprolactone polyols unique in polyurethanes?
What makes Polycaprolactone Polyols unique in polyurethanes? Polycaprolactone polyols are a special class of aliphatic polyester polyols, used in the soft block segment of high-performance polyurethane elastomers.
What is polycaprolactone used for?
Polycaprolactone (PCL) Polycaprolactone firstly synthesized in the 1930s, and now is used for the fabrication of biodegradable 3D printed scaffolds. PCL has elastic properties. PCL is used in various forms such as film, fibers, and micro-particle.
Is polycaprolactone biodegradable?
Polycaprolactone is a biodegradable polymer that undergoes hydrolytic degradation under physiological conditions. PC has become a subject of continuous research in regard to the development of artificial bone implants because of its fairly good dissolution tendency, excellent biocompatibility, and low MP (59–64°C).
What are the mechanical properties of poly (PCL)?
PCL exhibits mechanical properties similar to those of other conventional nonbiodegradable synthetic polymers. High molecular weight PCL has mechanical properties and oxygen permeability comparable to polyethylene (PE). This indicates that PCL is not suitable as oxygen barrier material.