Poly(acrylic acid) Chemische Eigenschaften,Einsatz,Produktion Methoden
R-Sätze Betriebsanweisung:
R45:Kann Krebs erzeugen.
R46:Kann vererbbare Schäden verursachen.
R34:Verursacht Verätzungen.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-Sätze Betriebsanweisung:
S53:Exposition vermeiden - vor Gebrauch besondere Anweisungen einholen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S27:Beschmutzte, getränkte Kleidung sofort ausziehen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
Beschreibung
Poly (acrylic acid) (PAA) is hygroscopic, brittle and colorless in nature with Tg at nearly 106oC. At temperatures above 200 to 250oC, it loses water and becomes an insoluble crosslinked polymer anhydride. Solubility of dried PAA in water increases with rise in temperatures. Concentrated solutions of PAA in water is thixotropic in nature.
Polyacrylic acid (PAA) is a hydrophilic colloidal solution, similar in properties to water-soluble natural gums. It is a clear, colorless, viscous stable solution. Applications include the modification of aqueous formulations for such end uses as cleaners, binders, adhesives, and emulsion paints. The sodium, potassium, and ammonium salts are effective thickeners and dispersants useful in both natural and synthetic latex systems. PAA in ceramic applications improves dry strength, dispersant action, and improved workability of the clays. PAA is stable to hydrolysis and is not susceptible to bacterial degradation.
Chemische Eigenschaften
white powder
Verwenden
Applications of PAA may include:
· to study solute diffusion in Polyvinyl alcohol/PAA copolymer hydrogel
· synthesizing poly(N-isopropylacrylamide)-block-PAA copolymer which responds to both temperature and pH stimuli
· in preparing block copolymer of oligo (methyl methacrylate)/PAA for micellar delivery of hydrophobic drugs
· as thickening agent for adhesives
Definition
ChEBI: An acrylic macromolecule, composed of acrylic acid repeating units.
Vorbereitung Methode
Carbomers are synthetic, high-molecular-weight, crosslinked polymers
of acrylic acid. These acrylic acid polymers are crosslinked
with allyl sucrose or allyl pentaerythritol. The polymerization
solvent used previously was benzene; however, some of the newer
commercially available grades of carbomer are manufactured using
either ethyl acetate or a cyclohexane–ethyl acetate cosolvent
mixture. The Carbopol ETD and Carbopol Ultrez polymers are
produced in the cosolvent mixture with a proprietary polymerization
aid.
Application
Poly acrylic acid and its derivatives are used in disposable diapers,ion exchange resins and adhesives. They are also popular as a thickening, dispersing, suspending and emulsifying agents in pharmaceuticals, cosmetics and paints. PAA inactivates the antiseptic chlorhexidine gluconate.
Allgemeine Beschreibung
Poly(acrylic acid) solution (PAA) is an anionic polymer that can be synthesized by the free radical polymerization of acrylic acid. It has a swelling nature that tends to absorb and retain the water. Its high ion exchange capacity makes it useful in the formation of membranes.
Inkompatibilitäten
Carbomers are discolored by resorcinol and are incompatible with
phenol, cationic polymers, strong acids, and high levels of
electrolytes. Certain antimicrobial adjuvants should also be avoided
or used at low levels. Trace levels of iron and other
transition metals can catalytically degrade carbomer dispersions.
Certain amino-functional actives form complexes with carbomer;
often this can be prevented by adjusting the pH of the
dispersion and/or the solubility parameter by using appropriate
alcohols and polyols.
Carbomers also form pH-dependent complexes with certain
polymeric excipients. Adjustment of pH and/or solubility parameter
can also work in this situation.
Regulatory Status
Included in the FDA Inactive Ingredients Database (oral suspensions,
tablets; ophthalmic, rectal, topical, transdermal preparations;
vaginal suppositories). Included in nonparenteral medicines licensed
in Europe. Included in the Canadian List of Acceptable Nonmedicinal
Ingredients.
Poly(acrylic acid) Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
