What is a resol resin?
What is a resol resin?
Definition of resol : a fusible resin soluble in alkali and alcohol that is formed as the first resin stage in the alkaline condensation of a phenol and an aldehyde to a phenolic resin, that consists essentially of a mixture of phenol alcohols, and that is used chiefly in laminating and impregnating paper and fabrics.
What is novolac and resol?
Novolac and resole are the products of phenol and formaldehyde, and are known as phenolic resins. The differences between novolac and resole are as follows: Novolac is produced using excess phenol and an acid or metal salt catalyst, whereas resole is produced using excess formaldehyde and a basic catalyst.
How is phenol-formaldehyde resin prepared?
In industrial practice, there are two basic methods for making the polymer into useful resins. In one method, an excess of formaldehyde is reacted with phenol in the presence of a base catalyst in water solution to yield a low-molecular-weight prepolymer called a resole.
What is a resole in chemistry?
Resoles are referred to as “one step” resins as they cure without a cross linker unlike novolacs, a “two step” resin. Resoles are major polymeric resin materials widely used for gluing and bonding building materials.
What is resol used for?
This product is used to replace fluids and minerals (such as sodium, potassium) lost due to diarrhea and vomiting. It helps prevent or treat the dehydration.
What is the structure of resol?
Sepiolite structure is established by a magnesium octahedral sheet in between two layers of silica tetrahedrons. This continues with an inversion of the apical ends every six units. Therefore, sepiolite has discontinuous octahedral sheet that provides rectangular tunnel, along the fibre axis.
How is novolac prepared?
Typically novolaks are prepared by the condensation of a mixture of p- and m-cresol with formaldehyde (as formalin). The reaction is catalyzed by acid. Oxalic acid is often used because it can be subsequently removed by thermal decomposition. Novolaks have a degree of polymerization of approximately 20-40.
How is resin prepared?
Nanocomposite materials of epoxy resin and silica were prepared by a simple procedure wherein diglycidyl ethers of bisphenol-A (DGEBA) as the pre- polymer of epoxy resin, tetraethoxysilane (TEOS) as silica source, and hexahydrophthalic anhydride (HHPA) were mixed together and heated at 170 °C in a sealed autoclave.
What is phenol-formaldehyde resin used for?
Phenol formaldehyde Resin or PF are synthetic high polymers. We can produce PF by the reaction with phenol and substituted phenol with formaldehyde. Besides polyurethanes and polyesters, phenolic and epoxy resins are the widely known applications for technical lignins in thermosetting materials.
What are phenolic resins used for?
Phenolic resins are good for high-temperature applications where parts must meet fire safety standards. Phenolic resins are used in a wide range of applications, including electronics, ballistics, mine ventilation, offshore water pipe systems, aerospace, rail and mass transit.
What are two stage resins?
The resins having the curing agent incorporated cure or “thermoset” to the desired degree when processed by the customer. Because an additional agent is required to complete the resin’s cure, the industry commonly refers to novolac resins as “two-stage” or “two-step” products.
What is phenolic powder?
The phenolic resins are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. Used as the basis for Bakelite, they were the first commercial synthetic resins (plastics). This step-growth polymerization reaction can be either acid- or base-catalyzed.