Cellulose acetate - Mn~70000 , CAS No.9004-35-7

CAS: 9004-35-7 Cat. No.: C1524260 EC Number: 618-380-7 PubChem CID: 17397575

GRADE & PURITY Mn~70000

Storage

Room temperature

Shipped In

Normal

Specifications

Specifications & Purity

Mn~70000

Storage

Room temperature

Shipped In

Normal

Names and Identifiers

Isomeric SMILES

C1=CC=C(C(=C1)NC(=O)C2=CSC(=N2)C3=CC=CS3)F

WGK Germany

nwg

PubChem CID

17397575

Chemical and Physical Properties

• Refractive Index: 1.475

Application Protocols

No item-specific, validated application protocols are provided in the Product Data. The following are general, literature-based starting points for common CA uses; adjust to your DS/MW and solvent system:

• Film casting (general):

  • Dissolve CA at 10 wt% in acetone/EtOH (9:1), stir 2–4 h until clear. Filter (0.45 μm). Cast on leveled glass with a 100–200 μm gap. Evaporate at ambient conditions, then post-dry at 50 °C for 2 h.

• Membrane (NIPS) fabrication (general):

  • Prepare 15 wt% CA in acetone/DMF (7:3) with 2–5 wt% PEG (pore former). Cast and immediately immerse in water bath (20–25 °C). Rinse until solvent-free; store wet in DI water with 0.02% NaN3 if needed.

• Electrospinning (general):

  • 12–18 wt% CA in acetone/DMF (2:1). Flow 0.3–0.8 mL/h, voltage 12–20 kV, tip-to-collector distance 10–15 cm, ambient RH 30–50%.

• Surface deacetylation (general):

  • Immerse film in 0.1 M NaOMe/MeOH at RT for 5–30 min. Rinse with MeOH then water; neutralize. Characterize by IR/contact angle.

Note: These are generalized procedures. Item-specific parameters (DS, viscosity, additives) are not specified for this item and should be verified on the CoA/Spec Sheet before scaling or critical use.

Biological Roles

• Origin and biocompatibility (general/literature):

  • Cellulose acetate is derived from cellulose, the most abundant biopolymer, obtained from wood pulp or cotton linters. While CA is not a native biological macromolecule, it retains the polysaccharide backbone and exhibits good biocompatibility in many in vitro contexts.

• Degradation considerations:

  • Hydrolytic and enzymatic deacetylation (esterases/lipases) can regenerate hydroxyl groups, ultimately yielding cellulose and acetic acid under suitable conditions. The rate depends on DS, crystallinity, and processing history.

• Laboratory bioscience uses (non-clinical):

  • CA membranes are used for electrophoretic separation of serum proteins and hemoglobins, protein immobilization, and blotting due to low background binding and uniform pore structures.
  • As scaffolding in tissue-engineering research (in vitro), electrospun CA mats provide tunable fiber diameters and surface chemistry after partial deacetylation to cellulose for improved hydrophilicity.

• Interaction with biomolecules:

  • Predominantly hydrophobic with limited hydrogen bonding unless partially deacetylated; surface functionalization (e.g., grafted carboxyl/amine groups) improves protein or nucleic acid affinity when required.

• Note: No medical or clinical claims are made. Suitability for biological applications should be verified for endotoxin/bioburden and extractables specific to the intended in vitro system. Item-specific bioburden and endotoxin levels are not specified for this item; consult the CoA/Spec Sheet if required.

Buffer Applications

• Applicability: Cellulose acetate itself is not a buffering agent. However, CA is widely used as a membrane/support material in electrophoresis and blotting workflows.

• Membrane-based applications (general/literature):

  • Protein electrophoresis: CA membranes employed for serum protein or hemoglobin electrophoresis using barbitone, Tris-glycine, or acetate buffers in the pH ~6–9 range, selected to optimize resolution of target protein bands.
  • Blotting/immobilization: CA’s relatively low nonspecific binding suits analyte transfer from gels. Prior wetting in appropriate buffer (e.g., Tris-glycine-methanol for SDS-PAGE transfers) improves uniform contact.

• Practical tips:

  • Pre-wet membranes with the running/transfer buffer to remove trapped air and ensure consistent conductivity.
  • Control ionic strength; high ionic strength increases heat generation and may dry membranes during longer runs—use cooling or intermittent wetting if needed.
  • For nucleic acids, nitrocellulose or nylon often provides higher binding; CA can be surface-modified to increase affinity after partial deacetylation.

• Item-specific details such as membrane pore size, thickness, and surface treatment are not specified for this item; refer to CoA/Spec Sheet if ordering CA in membrane form. For bulk resin/powder CA, formulate your own membranes/films using solvent casting and a suitable buffer-compatible wetting step before use.

Green Alternatives

• Material perspective (general): CA is a bio-derived polymer from cellulose and acetic anhydride; it is often viewed as a relatively sustainable engineering plastic compared with petro-derived analogs, particularly when processed with lower-toxicity solvents.

• Greener processing choices (literature/general):

  • Prefer acetone and ethyl acetate over chlorinated solvents (DCM, CHCl3) for dissolution and casting when solubility permits.
  • Use ethanol or isopropanol as co-solvents/nonsolvents in phase inversion instead of DMF or dioxane where feasible.
  • Investigate water-assisted phase inversion (NIPS) systems for membrane fabrication to reduce VOC emissions.

• Trade-offs:

  • Chlorinated solvents provide broader solubility, rapid drying, and smoother films but at higher EHS cost.
  • Acetone/EtOAc are flammable and fast-evaporating—require explosion-proof ventilation but offer improved environmental profiles.

• Comparison snapshot (literature values, indicative):

  • Acetone vs DCM
    • Health/Env: Acetone (low toxicity, non-HAP) vs DCM (suspected carcinogen, HAP)
    • Performance: Acetone good for many CA grades; DCM may dissolve higher-DS CA more readily.
  • Ethyl acetate vs MEK
    • Health/Env: EtOAc has favorable biodegradability and lower toxicity; MEK stronger solvency but higher worker exposure limits consideration.

• Materials alternatives:

  • If biodegradability or hydrolytic stability profiles are critical, compare CA with cellulose (water-insoluble), cellulose acetate butyrate (CAB), or polylactide (PLA). Selection should be based on DS, mechanical needs, and solvent footprint.

Pharmaceutical Uses

• Scope: Information below pertains to CA as a processing aid/excipient in research and development. No therapeutic/clinical claims are made.

• Typical formulation roles (general/literature):

  • Controlled-release membranes: CA films serve as semi-permeable barriers in osmotic pump designs and diffusion-controlled matrices; permeability can be tuned by DS and plasticizer content.
  • Coatings and microencapsulation: CA used as a film former for taste masking, moisture protection, and to modulate release in non-enteric coatings. (Note: Enteric performance typically uses cellulose acetate phthalate or other phthalates, not plain CA.)
  • Filtration media: CA membranes are widely used for sterile filtration of aqueous and organic solutions due to low protein binding and good flow characteristics.

• Processing considerations:

  • Residual solvent limits, extractables/leachables, and ash content must be controlled for pharmaceutical R&D contexts. Selection of acetone/EtOAc as processing solvents can simplify residual solvent compliance.
  • Plasticizers (e.g., triacetin, PEG) adjust film flexibility and permeation; their choice impacts stability and compatibility with actives.

• Standards and documentation:

  • Pharmacopeial monographs exist for related cellulose esters; verify whether your application requires specific monograph compliance and obtain CoA parameters (DS, viscosity, heavy metals, residual solvents) accordingly.

• Item-specific pharmacopeial status, bioburden, and residual solvent specifications are not provided for this item; consult the CoA/Spec Sheet for suitability in your intended R&D use.

Physical Properties

• Item-specific physical properties (from Product Data):

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Storage Conditions: Room temperature (provided)
  • Shipped In: Normal (provided)

• Polymer-specific note: Conventional BP/MP are not meaningful for this polymer; softening, glass transition, and decomposition temperatures are used instead.

• Typical properties (literature/general; ranges depend on DS, MW, and plasticizer):

  • Density: ~1.27–1.35 g/cm³ (literature)
  • Glass transition (Tg): ~150–190 °C for higher-DS CA without plasticizer; Tg decreases markedly with plasticizers (literature)
  • Softening/flow: begins above Tg; thermal degradation often >230–260 °C with acetic acid evolution (literature)
  • Solubility: Generally soluble in acetone, methyl ethyl ketone (MEK), ethyl acetate (EtOAc), dichloromethane (DCM), dioxane, acetonitrile/acetone mixtures; insoluble in aliphatic hydrocarbons and water. Lower-DS CA may require polar protic co-solvents (ethanol, methanol) (literature)
  • Water interaction: hygroscopic to a modest extent; films absorb moisture, affecting mechanical properties (literature)
  • Refractive index: ~1.47 at 20 °C (literature)

• Processing concentrations (literature guidance):

  • Solution casting typically 5–20 wt% in acetone or acetone/EtOH blends, depending on viscosity grade.

• Important: Exact DS, viscosity (cP or mPa·s in standard solvent), ash content, and residual solvent/moisture are not specified for this item; refer to CoA/Spec Sheet for item-specific specifications.

Quality & Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

• How CA is commonly specified (general/literature):

  • Degree of substitution (DS) or acetyl content (%): Primary determinant of solubility, Tg, and mechanical properties. Typical commercial CA spans DS ~2.0–2.7 (acetyl ~32–40%).
  • Viscosity grade: Often reported as solution viscosity (e.g., in acetone/EtOH at 25 °C) or by intrinsic viscosity [η]; correlates with average molecular weight and film strength.
  • Ash content/heavy metals and residual solvent: Relevant for membrane/analytical applications.
  • Particulate/appearance: Flakes, powder, or pellets; color (water-white to pale). Low color/low haze is desirable for optics/films.
  • Additives: Some grades are pre-plasticized or contain processing aids; absence/presence should be disclosed on the CoA.

• Grade use-cases (general):

  • Membrane/filtration grade: Tight control of particle/gel content for uniform pore formation.
  • Analytical/low-UV grade: Lower extractables/absorbance for spectroscopic work.
  • Fiber/film grade: Targeted viscosity for spinning/casting.

• Guidance for this item:

  • Because grade, DS, and viscosity are not specified here, confirm these on the CoA/Spec Sheet before selecting solvent systems or defining processing parameters. Stabilizers or plasticizers, if present, should also be checked, as they significantly alter Tg, solubility, and mechanical behavior.

Reaction & Applications

• Materials science applications (general/literature):

  • Membranes and separations: Phase inversion casting yields micro/ultrafiltration membranes; tunable porosity via nonsolvent-induced phase separation (NIPS) using acetone/DMF/EtOH–water systems.
  • Coatings/films: Optical films, barrier coatings, protective lacquers, and biodegradable packaging components.
  • Fibers: Dry/wet spinning into filaments; electrospun mats for filtration and scaffolding.
  • Chromatography and sample prep: CA membranes for protein electrophoresis and blotting; supports for immobilization after surface functionalization.

• Chemical modification (general):

  • Partial deacetylation (e.g., NaOMe/MeOH, mild base) to introduce free –OH for subsequent grafting.
  • Esterification/urethane formation on residual –OH (e.g., acyl chlorides or isocyanates) for tuning hydrophilicity or adding ligating groups.
  • Click-ready handles introduced via tosylation followed by azidation, enabling CuAAC on the surface or in bulk.

• Practical processing tips:

  • Dry polymer at 40–60 °C under vacuum (overnight) to remove moisture before dissolution; moisture alters viscosity and phase inversion behavior.
  • Filter polymer solutions (0.45 μm) prior to casting to remove gels/particulates; degas to avoid pinholes.
  • Control solvent evaporation rate and humidity to manage film stress and porosity; for NIPS, document ternary phase diagram for your solvent/nonsolvent system.

• Note: Manufacturer Applications were not provided beyond category placement; above reflects common research uses for cellulose acetate in materials science.

Reaction Conditions

• Dissolution and processing (literature/general):

  • Typical dissolution: 5–15 wt% CA in acetone or acetone/EtOH (80:20) at RT to 40 °C with stirring until clear (1–12 h depending on MW). Pre-dry CA to improve consistency.
  • Film casting: Doctor blade or spin coat; dry under controlled RH (30–60%) to manage stress and porosity. Post-dry at 40–60 °C to constant weight.

• Representative chemical modifications (literature guidance):

  • Partial deacetylation: NaOMe (0.05–0.5 M) in MeOH, 0–25 °C, minutes to hours, monitored by IR (decrease at ~1740 cm⁻¹) and acetyl content titration. Quench and wash thoroughly.
  • Re-acetylation or mixed-ester formation: Ac2O/pyridine or Ac2O/DMAP at 0–25 °C for surface work; for bulk modification, dissolve CA first, then react under inert atmosphere.
  • Tosylation of –OH: TsCl (1–3 eq per –OH), pyridine or CH2Cl2/pyridine, 0 °C to RT, 2–24 h; follow with NaN3 in DMF (60–90 °C) to install azide.
  • Urethane linkage formation: Isocyanates (1–2 eq per –OH) in dry CH2Cl2 or THF with DBTDL or catalyst-free at RT–50 °C, hours; avoid moisture.

• Membrane fabrication (NIPS, literature):

  • Dope: CA in acetone/DMF (e.g., 12–20 wt% total polymer) with pore formers (PEG). Cast at RT, immerse in nonsolvent bath (water or water/alcohol). Adjust bath temperature and solvent strength to tune pore size.

• Yields/extent: Reported conversions depend on accessibility in the amorphous phase; surface-selective reactions are common. Always optimize against your specific DS/MW (not specified for this item).

Safety & Handling

• GHS and hazard statements (from Product Data):

  • Signal Word: Not specified for this item; refer to SDS.
  • H-Statements: Not specified for this item; refer to SDS.
  • GHS Classification/Pictograms: Not specified for this item; refer to SDS.

• General safety profile (literature/general):

  • Low acute toxicity polymer; combustible solid. Fine powders can form combustible dust–air mixtures. Thermal decomposition releases acetic acid and irritating fumes.
  • Avoid generating dust and ignition sources. Use adequate ventilation during dissolution and film casting, particularly with volatile organic solvents (e.g., acetone, DCM, MEK).

• Incompatibilities (general):

  • Strong oxidizers; strong acids/bases that hydrolyze ester linkages; nitrating agents. Swells/softens in many organic solvents.

• Recommended PPE:

  • Safety glasses or goggles, lab coat, and suitable chemical-resistant gloves (e.g., nitrile) when handling solid and solutions. Use dust mask/respirator if dust is generated; employ fume hood for solvent processing.

• First-aid overview (general guidance; defer to SDS):

  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Skin contact: Wash with soap and water; remove contaminated clothing.
  • Eye contact: Rinse cautiously with water for several minutes; remove contacts if present and easy to do.
  • Ingestion: Rinse mouth; seek medical advice if unwell.

• Fire-fighting (general):

  • Use water spray, dry chemical, CO2, or foam. Combustion may produce CO/CO2 and acetic acid; firefighters should wear self-contained breathing apparatus.

Solvent Selection

• Solubility principle (general/literature): CA dissolves in moderately polar aprotic solvents and certain esters/ketones; solvent choice is highly dependent on DS and MW.

• Common solvent systems for CA processing (literature):

  • Ketones/esters: Acetone (benchmark), MEK, ethyl acetate. Often used neat or with 5–30% lower alcohols (EtOH, MeOH) to tune viscosity, evaporation, and film microstructure.
  • Chlorinated: Dichloromethane, chloroform—excellent solvents but with higher EHS burdens; consider only when required.
  • Ethers/nitriles: 1,4-Dioxane, acetonitrile (frequently as mixtures).
  • Alcohol co-solvents: Aid dissolution of lower-DS CA by hydrogen bonding.

• Polarity/miscibility (literature):

  • Acetone: polar aprotic (ε ~21), fully miscible with many organics, fast-evaporating for rapid film formation.
  • Ethyl acetate: greener profile, slower evaporation, improves leveling.
  • DCM: powerful solvent for high-DS CA, rapid drying; handle with strict containment.

• Practical selection tips:

  • Start with acetone (5–15 wt% solids) for film casting and general coatings; add 5–20% EtOH to reduce drying stress and orange peel.
  • For thick, defect-free films or membranes, blend acetone/EtOAc or acetone/MeOH to modulate evaporation and phase inversion behavior.
  • For electrospinning, use acetone/DMF or acetone/AcCN blends to balance conductivity and volatility (verify compatibility with your DS grade).

• Note: Item-specific DS/viscosity unspecified—pilot small-scale solubility tests are recommended.

Storage & Reconstitution

• Storage (from Product Data):

  • Store at room temperature.
  • Shipped under normal conditions.

• General storage guidance (literature/best practice):

  • Keep tightly closed in a cool, dry place away from direct sunlight and ignition sources. Protect from moisture to maintain consistent viscosity/processing behavior. For long-term storage, desiccation is recommended.
  • Avoid strong acids/bases and oxidizers. Segregate from nitrating agents.

• Reconstitution/dissolution (general):

  • Pre-dry the polymer at 40–60 °C under vacuum overnight for reproducible solution properties.
  • Typical dissolution: add CA slowly to a vortex of acetone or acetone/EtOH (80:20) at RT, target 5–15 wt% solids. Stir until fully dissolved (1–12 h depending on MW). Gentle warming (≤40 °C) can accelerate dissolution; avoid overheating.
  • For difficult grades, use acetone/DMF or DCM/EtOAc blends, verifying compatibility and EHS constraints.

• Solution handling:

  • Filter through 0.45 μm PTFE or PES to remove gels/particulates. Degas to reduce pinholes in cast films.
  • Store solutions in airtight containers to minimize solvent loss and moisture uptake; use within days to weeks depending on solvent volatility and bioburden controls.

• Stability note:

  • Item-specific stabilizers/additives are not specified for this item; refer to CoA/Spec Sheet. Avoid prolonged exposure above Tg to prevent thermal history effects or discoloration.

Structure & Identity

• Polymer overview: Cellulose acetate (CA) is a partially to fully acetylated derivative of cellulose, consisting of β-1→4 linked D-glucopyranose units bearing a variable number of acetyl ester groups on the C2, C3, and/or C6 hydroxyls. The extent of acetylation is commonly expressed as degree of substitution (DS, 0–3 per anhydroglucose unit).

• Item-specific identifiers (from Product Data):

  • CAS: 9004-35-7
  • CID: 17397575
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet. (Note: linear SMILES is not uniquely defined for polymers.)
  • InChIKey: Not specified for this item; refer to CoA/Spec Sheet. (Not uniquely defined for polymers.)
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet. (Empirical formulas vary with DS.)
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet. (Polymer; typically reported as viscosity-average or weight-average MW.)

• Structural features (general/literature):

  • Backbone: linear polysaccharide of repeating anhydro-D-glucose units (AGU) linked via β-1→4 glycosidic bonds.
  • Functional groups: secondary alcohols (residual OH), acetate esters (–O–C(=O)CH3), acetal linkages of the pyranose ring, occasional reducing-end aldehyde in minor proportion.
  • Stereochemistry: all-axial/equatorial configuration inherent to cellulose (D-glucose, chair conformation); β-glycosidic linkage at C1.

• 2D description in words: A linear chain of six-membered pyranose rings connected head-to-tail via oxygen bridges, each ring bearing up to three acetate ester substituents in place of native hydroxyls at the C2, C3, and C6 positions.

• Degrees/grades note: Properties and solubility depend strongly on DS and molecular weight; these parameters are not specified for this item and should be verified from the CoA/Spec Sheet.

Synthetic Utility

• Role as a functional polymer scaffold (general/literature):

  • Residual hydroxyl groups on partially acetylated CA allow further derivatization, enabling CA to serve as a macromolecular support for catalysts, ligands, or affinity groups.
  • The acetate groups can be selectively deprotected to regenerate cellulose domains, creating amphiphilic materials or patterned surfaces.

• Representative transformations on CA:

  • Tosylation of residual –OH (pyridine or DMAP-catalyzed), followed by nucleophilic substitution (e.g., azidation) to introduce clickable handles (CuAAC, SPAAC).
  • Esterification with carboxylic acids (via acid chlorides/anhydrides) or urethane formation with isocyanates to adjust hydrophilicity, introduce ionic groups, or immobilize catalysts.
  • Surface oxidation (TEMPO-mediated on regenerated –OH) to carboxylates for polyelectrolyte formation and bioconjugation.

• Uses in synthesis and separations:

  • Support for heterogeneous catalysis or organocatalysis after ligand grafting; improved handling and recyclability.
  • Chiral stationary phases: derivatized cellulose esters (including CA-based) are used to prepare chiral selectors for HPLC—immobilization on silica is a common route.
  • Membrane-assisted synthesis: CA membranes employed to confine reagents, mediate diffusion, or perform solvent exchange in flow setups.

• Practical notes:

  • Control DS and substitution patterns to maintain solubility/film integrity during multi-step functionalization.
  • Monitor degree of modification by IR (νC=O shift), solid-state NMR, or titration of introduced functional groups. Item-specific DS and viscosity are not provided—pilot derivatization accordingly.

Target Specificity

Not applicable. This product is a polymeric material, not an antibody, enzyme, or ligand with defined biological target specificity. If using CA as a support for affinity ligands, the specificity will be determined by the immobilized molecule rather than by cellulose acetate itself.