Phenol formaldehyde resins (PF) or phenolic resins (also infrequently called phenoplasts)
are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. Used as the basis for Bakelite, PFs were the first commercial synthetic resins (plastics).
Is phenol formaldehyde cross linked?
Abstract. Phenol-formaldehyde resins (resols) are the
preferred crosslinking agents
for the dynamic vulcanization of blends of polypropylene and ethylene—propylene—diene rubber (PP/EPDM) for the production of thermoplastic vulcanizates (TPVs).
Is phenol formaldehyde resin cross linked polymer?
Phenol-formaldehyde resin, also called phenolic resin, any of a number of synthetic resins made by reacting phenol (an aromatic alcohol derived from benzene) with formaldehyde (a reactive gas derived from methane). Phenol-formaldehyde resins were
the first completely synthetic polymers
to be commercialized.
What is the formula of phenol formaldehyde resin?
| PubChem CID 24754 | Chemical Safety Laboratory Chemical Safety Summary (LCSS) Datasheet | Molecular Formula C 8 H 6 O 2 | Synonyms Phenol-formaldehyde resin Phenolic resin Phenol, polymer with formaldehyde Formaldehyde phenol polymer Formaldehyde, phenol polymer More… | Molecular Weight 134.13 |
|---|
What is the phenol to formaldehyde ratio for novolac resin?
Upon heating the novolac resins to about 165°C in a mold, the HEXA decomposes to provide the formaldehyde necessary for the final curing. The addition of HEXA gives the resin a final working phenol-formaldehyde molar ratio of
1:1.5
. Novolac phenolic resins have an infinite shelf life under normal storage conditions.
What are phenolic resins used for?
Phenolic resins are found in a myriad of industrial products. They are mainly used in the
production of circuit boards
. They are better known for the production of molded products including billiard balls, laboratory countertops, and as coatings and adhesives.
What is the another name of phenol formaldehyde resin?
Phenol formaldehyde resins (PF) or phenolic resins (also infrequently called
phenoplasts
) are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. Used as the basis for Bakelite, PFs were the first commercial synthetic resins (plastics).
Is it possible to grind up and reuse phenol formaldehyde?
(a)
It is not possible to grind up
and reuse phenol-formaldehyde because it is a network thermoset polymer and, therefore, is not amenable to remolding.
What are the properties of phenol formaldehyde?
Properties of Phenolic Resins
In addition, phenol formaldehyde resin properties include
good thermal insulation, low density and excellent durability
. They are easy to mold into a variety of shapes and complex contours, making them adaptable to custom equipment or environments.
How much time is taken for the formation of phenol formaldehyde?
The synthesis time was observed for
240 min
; changes in physical structure and viscosity of the PF resins were noted. It was observed that the viscosity values of the PF resins prepared were directly proportional to the synthesis temperature and the formaldehyde content.
How do you make phenol formaldehyde?
Preparation of EHL–PF resin. Phenol and formaldehyde in molar ratio of
1:1.5
, sufficient EHL to substitute 5–25 wt% of the phenol, NaOH and water were mixed in a flask. The mixture was heated for 1 h at 80 °C then rapidly cooled to 65 °C. The product was dehydrated in vacuum until its viscosity was 1000–2500 MPa s.
Is formaldehyde used in plastics?
1 Formaldehyde (Chemical Composition) … Moreover, formaldehyde is extensively used in the production of polymers and other materials. Although formaldehyde is known in various forms, it is more popularly known in its resin form, where it is most commonly used as a
thermosetting resin or plastic
.
Where is formaldehyde used?
Formaldehyde is a strong-smelling, colorless gas used in making building materials and many household products. It is used in
pressed-wood products
, such as particleboard, plywood, and fiberboard; glues and adhesives; permanent-press fabrics; paper product coatings; and certain insulation materials.
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.
Is phenolic resin waterproof?
Phenolic Formaldehyde resin are one kind of thermosetting resin with
heat resistant, waterproof
and the most used for exterior application or superior water resitance (e.g. external wall house, roof), with low formaldehyde excess.
What is the reagent is used in the preparation of phenol formaldehyde resin?
Novolaks (or novolacs) are phenol-formaldehyde resins with a formaldehyde to phenol molar ratio of less than one. In place of phenol itself, they are often produced from cresols (methyl phenols) and the polymerization is completed by using acid-catalysis
(sulfuric acid, oxalic acid, hydrochloric acid)
.
