| HS Code | 425122 |
| Product Name | Avicor 325 |
| Active Ingredient | Acetylsalicylic acid (aspirin) |
| Strength | 325 mg per tablet |
| Dosage Form | Tablet |
| Therapeutic Class | Nonsteroidal anti-inflammatory drug (NSAID); antiplatelet agent |
| Indications | Relief of pain, fever, and inflammation; prevention of myocardial infarction and stroke |
| Mechanism Of Action | Irreversibly inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis and platelet aggregation |
| Route Of Administration | Oral |
| Usual Dosage | Cardiovascular prophylaxis: 325 mg once daily; analgesic/antipyretic: 325-650 mg every 4-6 hours as needed |
| Contraindications | Active peptic ulcer, bleeding disorders, hypersensitivity to aspirin or other NSAIDs, children with viral illness |
| Common Side Effects | Nausea, dyspepsia, abdominal pain, gastrointestinal bleeding, prolonged bleeding time, tinnitus |
| Storage Conditions | Store at room temperature in a dry, well-closed container, protected from light and moisture |
| Manufacturer | Avicenna Pharmaceutical (Pvt) Ltd |
As an accredited Avicor 325 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Avicor 325 is supplied in 25 kg multilayer bags with an inner polyethylene liner for moisture protection. |
| Container Loading (20′ FCL) | Avicor 325 is packed as a 20-foot full container load, with secure, stable loading for safe chemical transport. |
| Shipping | Avicor 325 (microcrystalline cellulose) is a non-hazardous, free-flowing white powder. Ship in clean, dry, double-lined polypropylene bags or tote bags, away from contaminants and moisture. No UN number, hazard class, or IMDG/IATA restrictions apply; normal freight and standard temperature conditions are acceptable. |
| Storage | Store Avicor 325 in a tightly sealed original container, in a cool, dry, well-ventilated area away from direct sunlight and moisture. Avoid humid conditions, as the powder may absorb water and degrade. Keep away from strong oxidizers and open flames. Ensure containers are firmly closed after each use to maintain product integrity. |
| Shelf Life | The shelf life of Avicor 325 is typically two years when stored in its original, unopened container at controlled room temperature. |
Sodium hypochlorite storage is a severe oxidative environment for thermoset liners, particularly at temperatures above 40 °C and available chlorine concentrations above 15 wt%. The active oxidant is not chlorine gas alone; hypochlorous acid and hypochlorite anion both participate in electrophilic degradation of the cured polyester backbone. In epoxy vinyl ester systems, the hydrolytic resistance of the methacrylate crosslink network delays chain scission. Avicor 325 is used as the resin matrix for the inner corrosion liner. The liner construction excludes a process-side gel coat because cobalt inhibition can interfere with cure. The first process-side layer is a resin-rich veil. Two layers of Nexus veil are saturated with Avicor 325 at a resin-to-fibre ratio of 90:10 by mass. The veil is followed by three layers of 450 g/m² ECR chopped strand mat. Total corrosion barrier thickness is specified at 4 mm. The structural wall is built with alternating mat and woven roving to the design thickness. A post-cure of 4 h at 95 °C is applied. The critical failure modes observed in production liners are blistering at the veil interface and star cracking at high-exotherm corners. These defects occur when peroxides are over-dosed. The correct initiation system is MEKP at 1.2 phr with cobalt naphthenate 6% at 0.2 phr for shop temperatures from 20 °C to 25 °C. Amine-based additives must be excluded from the mixing area because trace amines can destabilize peroxide and trigger premature polymerization. Gel time is checked per ISO 2535; the target window is 18–25 min. The laminate is not placed into sodium hypochlorite service until hardness exceeds 38 Barcol on the inner surface per ASTM D2583 and residual styrene is below 0.1 wt% per ISO 4901.
| Service exposure condition | Test protocol | Target acceptance criterion |
|---|---|---|
| Sodium hypochlorite, 15 wt% available chlorine at 40 °C, six months | ASTM C581-20 | Barcol retention ≥ 90%; no blisters, cracks, or exposed fibres |
| Sulfuric acid, 25 wt% at 80 °C, 112 days | ISO 175:2010 | Mass change ≤ ±1.0%; dimension change ≤ ±0.5% |
| Chlorine water, 60 °C, 112 days | ISO 175:2010 | Mass change ≤ 1.5%; no visible fibre attack |
Outlet ducting that carries saturated flue gas downstream of a wet absorber does not experience a stable liquid film. The metal substrate temperature frequently crosses the sulfuric acid dew point. Condensate forms when the duct wall drops below roughly 120 °C in high-sulfur coal plants, then evaporates during low-load operation. The result is a cyclic wet-dry acid exposure with dissolved chlorides concentrated by evaporation. Avicor 325 is applied as a trowelled lining on carbon steel duct floors and side walls. The lining is installed after abrasive blasting to Sa 2½ per ISO 8501-1, followed by a primer at 0.5 mm wet film thickness. The trowel-applied mortar uses Avicor 325 loaded with 20–30 phr silica flour to produce a 4 mm first pass. A second pass is applied with a smooth finish. The lining is then roller-combed to remove entrapped air. Air removal is essential because voids become chloride concentration cells. The duct lining is post-cured at 90 °C for 4 h, then inspected with high-voltage holiday testing at 3 kV/mm per ASTM D5162-15. Pin holes below 1 mm diameter are repaired with catalysed resin from the same batch. The coefficient of thermal expansion difference between the vinyl ester lining and carbon steel is accommodated by a 100 mm wide glass mat transition strip at all flanged connections. Cut edges are buttered with resin paste. The lined duct is not returned to service until the inner surface hardness reaches 35 Barcol per ASTM D2583 and the moisture content of the laminate is below 0.5 wt% by Karl Fischer titration per ISO 15512.
Where spent sulfuric acid is transferred across a concrete containment bund, the liner is subjected to intermittent acid immersion, heavy forklift traffic, and substrate moisture vapour drive. The application is a trowelled flooring and wall cove system based on Avicor 325. Concrete is prepared by mechanical scarification to a surface profile of CSP 3–5 per ICRI Guideline No. 310.2R. The prepared surface is primed with a low-viscosity mix of Avicor 325 and 10 wt% fumed silica. The body coat is filled with 30 phr quartz sand and applied at 2 mm wet thickness. The topcoat is broadcast with 0.6–1.2 mm quartz aggregate to provide slip resistance. The system is post-cured at 25 °C for 24 h before use. Bond strength is measured by pull-off test in accordance with ASTM D7234; values below 2.0 MPa indicate cohesive failure within the concrete or primer. Published comparative bond data for Avicor 325 over damp concrete in this specific configuration is limited; therefore, on-site test patches are mandatory when substrate moisture emission exceeds 3 lb/1000 ft²/24 h by ASTM F1869. Vinyl ester linings should not be applied to concrete with residual amines from curing compounds; the amines act as peroxide decomposition inhibitors and can produce a soft tacky interface. Chemical resistance of the cured flooring system is verified in the laboratory using ASTM C581-20 immersion in 30 wt% sulfuric acid at 80 °C for six months. The acceptance criteria are Barcol retention above 85% and no visible fibre separation.Moulded open-mesh grating fabricated from Avicor 325 is a high-exotherm process. The liquid resin is mixed with fumed silica at 3.0–5.0 phr to obtain a thixotropic index above 2.8 by ISO 2555. Talc or calcium carbonate is added at 15–25 phr to control peak temperature and reduce shrinkage. The fillers must be low in moisture and free of clay contaminants. The mix is catalysed with MEKP at 1.0–1.2 phr and poured into a steel female mould that is preheated to 35 °C. The mould cells are typically 38 mm deep and 38 mm wide. A thermocouple is inserted at the centre of the deepest mould cavity. Peak exotherm temperature is not allowed to exceed 105 °C. If the temperature exceeds 105 °C, the cured cell corners show microcracks because of thermal degradation in the high-thickness zone. Peak exotherm is suppressed by limiting each pour to 18 kg, adding filler in the upper half of the range, and using forced-air cooling under the mould at 60 m³/min. The part is demoulded after the centre temperature falls below 45 °C. Post-cure is performed in a forced-air oven for 5 h at 90 °C. Barcol hardness is measured at five points per panel per ASTM D2583; readings below 35 indicate incomplete cure at the cell radius. Residual styrene is checked by ISO 4901 on a drilled core sample from the thickest section. The target is less than 0.1 wt%. The final part is then subjected to a 24 h immersion in boiling water as a quality check for microcrack formation. Any visible star cracking at the cell intersection is cause for batch rejection.
Chlorine wet gas ducts in a chlor-alkali plant carry a condensate that is simultaneously oxidizing and chloride-saturated. Gas temperature at the outlet of the first cooling stage can fall from 85 °C to 35 °C. Condensate pH may be below 2.0 because of hydrolysed chlorine species. Duct sections fabricated from Avicor 325 are usually produced by filament winding on a steel mandrel. The mandrel is coated with a release system that does not contain silicone. The corrosion liner is built from two layers of Nexus veil and a 1.5 mm resin-rich layer. The structural wall is wound at a helix angle of 55° with ECR glass roving. Wall thickness is 8 mm for sections up to 600 mm inside diameter. The wound laminate is cured in a rotating fixture under infrared lamps for 40 min at 75 °C. The section is then post-cured at 100 °C for 4 h. Dimensional tolerance is measured per ISO 8483; a diameter deviation above ±0.5 mm is rejected because it induces gasket leakage at flanges. Flange faces are machined after cure. Exposed machined surfaces are sealed with a thin coat of unfilled Avicor 325. The sealing coat is allowed to gel, then post-cure. The duct sections are hydrotested at 1.5 times the design pressure before installation. Design pressure for these ducts is commonly 0.5 bar for ventilation service. Long-term chemical resistance of the duct material is evaluated by immersion in a synthetic chlorine water solution at 60 °C under ISO 175:2010. Mass change after 112 days must be below 1.5%.
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Within corrosion-resistant fiber-reinforced plastic fabrication, the resin system designated Avicor 325 is handled as an unpromoted bisphenol A epoxy vinyl ester dissolved in styrene monomer. The 325 model designation is supplier-specific and identifies the unpromoted, medium-viscosity, non-thixotropic base resin within the producer’s series. The resin is intended for room-temperature cure after cobalt promotion and methyl ethyl ketone peroxide initiation, and it is used in contact-molded linings, filament-wound pipe, ductwork, stack liners, scrubber internals, and secondary containment barriers where resistance to aqueous acids, caustic, and organic solvents is required. Liquid-state specifications recorded under ASTM D2196-20 Brookfield methods give a nominal viscosity of 300–350 mPa·s at 25°C using spindle 2 at 20 rpm; density under ASTM D1475-13 falls between 1.03 and 1.06 g/cm³. Manufacturer safety data sheet information places styrene monomer content in the range of 35–40 wt%, and the product is not formulated as a low-styrene-emission grade. Compared with orthophthalic polyester resins, the cured vinyl ester network exhibits higher hydrolytic stability and better elongation at break, which reduces microcrack formation in tank linings subjected to thermal cycling. Compared with a higher-viscosity standard bisphenol A vinyl ester, the lower viscosity permits faster wet-out of continuous roving; however, the working time at equivalent methyl ethyl ketone peroxide concentration is shorter and requires tighter workshop temperature control.
Promotion and cure are performed with cobalt naphthenate or cobalt octoate at 0.2–0.3 wt% of a 6% cobalt solution, followed by addition of methyl ethyl ketone peroxide at 1.0–1.75 wt%. The working time is strongly mass-sensitive; a 100 g cup gel at 25°C is recorded under ASTM D2471-99 at 18–22 min with 1.25 wt% methyl ethyl ketone peroxide, but a 20 kg resin bath in continuous filament winding may remain sufficiently low in viscosity for only 35–45 min before wet-out declines. Workshop temperatures below 15°C require pre-warming of the resin to 20–25°C; above 32°C the exotherm accelerates and pot life may fall below 12 min, producing premature gelation in resin transfer lines. The initiated laminate should be prepared under controlled humidity. Glass reinforcement should be pre-dried at 60°C for 4 h when shop relative humidity exceeds 60%, because absorbed water interferes with silane coupling at the glass-resin interface and reduces interlaminar shear strength. Bulk preparation in unlined carbon steel tanks is prohibited because cobalt-promoted resin can react with iron surfaces and discolour; 304 or 316 stainless steel or polyethylene equipment is preferred.
In filament winding of 200–600 mm diameter pipe, the medium viscosity of Avicor 325 is typically maintained at 28–32°C in jacketed resin baths to hold spindle viscosity between 250 and 350 mPa·s. Production records from tension-controlled roving creels show that resin bath temperature excursions above 35°C increase the gel fraction in return lines and generate hard particles that block 80 mesh resin filters. Batch-to-batch viscosity variation is commonly reported at ±10%; when the incoming resin is at the upper viscosity limit, fabricators reduce line speed by 10–15% to maintain complete wet-out. For spray-up, the resin is used with internal mixing spray guns fitted with 0.043 in fluid nozzles and atomization pressure between 0.28 and 0.35 MPa. The resin can also be applied by hand lay-up with 450 g/m² chopped strand mat and a surface veil to produce a 3 mm corrosion barrier at a wet resin coverage of 0.5–0.8 kg/m². These parameters are practical starting points, but published data for the specific configuration of Avicor 325 with carbon veil in 1.5 mm conductive linings is limited, and electrostatic dissipative service therefore requires project-specific validation.
The cured mechanical properties of Avicor 325 place it between standard bisphenol A vinyl ester and novolac vinyl ester grades. Typical values for clear castings are given in the comparative table below; all specimens are post-cured at 4 h at 80°C and 2 h at 120°C. Tensile and flexural properties are determined by ASTM D638-14 and ASTM D790-17, respectively. Heat deflection temperature is measured under ASTM D648-18 at 1.82 MPa, and Barcol hardness is reported under ASTM D2583-07. Additional thermal analysis by differential scanning calorimetry using ASTM D3418-21 gives a glass transition temperature of 118–122°C after full post-cure. This distinguishes Avicor 325 from flexible vinyl esters with a glass transition temperature below 90°C and from novolac grades above 135°C.
| Property | Avicor 325 | Standard bisphenol A vinyl ester reference | Novolac vinyl ester reference |
|---|---|---|---|
| Brookfield viscosity at 25°C, spindle 2, 20 rpm | 300–350 mPa·s | 400–500 mPa·s | 200–300 mPa·s |
| Tensile strength, ASTM D638-14 | 82 MPa | 84 MPa | 76 MPa |
| Tensile modulus, ASTM D638-14 | 3.2 GPa | 3.3 GPa | 3.5 GPa |
| Elongation at break, ASTM D638-14 | 4.8% | 5.0% | 3.0% |
| Flexural strength, ASTM D790-17 | 120 MPa | 124 MPa | 105 MPa |
| Flexural modulus, ASTM D790-17 | 3.1 GPa | 3.2 GPa | 3.5 GPa |
| Heat deflection temperature at 1.82 MPa, ASTM D648-18 | 102°C | 105°C | 125°C |
| Barcol hardness, ASTM D2583-07 | 40 | 40 | 42 |
The primary difference in the comparative profile is the heat deflection temperature and elongation balance. Avicor 325 retains sufficient strain tolerance for thermal-shock absorption in acid service linings, while a novolac vinyl ester offers higher heat deflection temperature but lower strain tolerance. Selection therefore depends on whether the service condition is cyclic thermal shock or sustained high-temperature oxidizing acid attack.
In dilute sulfuric acid service at 25–60°C, the bisphenol A epoxy backbone and methacrylate terminal unsaturation of Avicor 325 provide better resistance to ester hydrolysis than an isophthalic polyester. The cured network has lower ester density and the ester groups are sterically shielded, which reduces the rate of chain scission in aqueous acid. In a typical 3 mm corrosion barrier backed by a structural polyester laminate, Avicor 325 is applied with a surface veil followed by 450 g/m² chopped strand mat. This replacement avoids the ester-rich regions of orthophthalic polyesters that cause blistering and fibre debonding in immersion service. Relative to a standard bisphenol A vinyl ester, the lower viscosity of Avicor 325 permits one-pass wet-out of heavy fabrics; relative to a flexible-grade vinyl ester, it has lower elongation and should not be used as the sole resin in high-strain secondary containment membranes. Avicor 325 is not a substitute for novolac vinyl ester in concentrated sulfuric acid above 70% or in strong oxidizing media such as hot nitric acid, where aromatic novolac structures are required. The resin is also not recommended for continuous immersion in chlorinated solvents above 40°C.
Post-cure of Avicor 325 laminates is required for full development of corrosion resistance. After 24 h at 25°C, the laminate reaches approximately 80% of its ultimate Barcol hardness; full chemical resistance is achieved after a step post-cure of 4 h at 80°C and 2 h at 120°C. For thick sections above 12 mm with gel coats, the temperature ramp between 60°C and 80°C should not exceed 0.5°C/min to avoid exothermic cracking. Field experience with 25 mm flanges fabricated in 40°C ambient conditions shows that uncontrolled exotherm can produce centerline delamination; therefore, multiple thin layers are preferred over a single thick pour. The maximum neat-resin casting thickness without thermal cracking is 6–8 mm under ambient cure. Open lay-up at 30°C typically loses 8–12% of total resin weight through styrene evaporation; extraction ventilation must maintain styrene vapour below the applicable workplace exposure limit, and waste catalyst-promoted resin must be spread in thin layers to avoid high exotherm in collection containers.
Qualification of Avicor 325 for chemical service is conducted according to ASTM C581-20, in which glass-reinforced coupons are immersed in the target chemical at the design temperature for 6–12 months; acceptability is based on retention of flexural strength and modulus and visual absence of cracks, blisters, and fibre exposure. The resin and cured laminate are also evaluated for water absorption under ASTM D570-22, tensile properties under ASTM D638-14, and flame spread under ASTM E84-23 where building ductwork requires surface burning classification. Regulatory documentation includes REACH Regulation (EC) No 1907/2006 for substances of very high concern screening, EU RoHS Directive 2011/65/EU for restricted heavy metals, and, where potable water contact is proposed, absence of specific migration is verified under the applicable national standard rather than a generic FDA clearance. Lot-specific compliance documentation should be maintained by the fabricator for each resin batch.
| Requirement | Standard/Designation | Evaluation Condition | Typical Result or Status |
|---|---|---|---|
| Liquid resin viscosity | ASTM D2196-20 | Brookfield RV, spindle 2, 20 rpm, 25°C | 300–350 mPa·s |
| Liquid density | ASTM D1475-13 | Pycnometer, 25°C | 1.03–1.06 g/cm³ |
| Gel time | ASTM D2471-99 | 100 g mass, 25°C, 1.25 wt% methyl ethyl ketone peroxide | 18–22 min |
| Tensile properties | ASTM D638-14 | Type I specimen, 5 mm/min | 82 MPa tensile strength, 3.2 GPa modulus, 4.8% elongation |
| Flexural properties | ASTM D790-17 | Three-point bend, span-to-depth 16:1 | 120 MPa flexural strength, 3.1 GPa flexural modulus |
| Heat deflection temperature | ASTM D648-18 | 1.82 MPa fibre stress | 102°C |
| Chemical resistance | ASTM C581-20 | Coupon immersion at design temperature | Lot-specific flexural retention and visual rating |
| Water absorption | ASTM D570-22 | 24 h immersion, clear casting | <0.15% |
| Surface burning | ASTM E84-23 | Panel thickness and filler system as installed | Class A or Class B depending on laminate configuration |
Operational boundaries apply to grade selection. Avicor 325 is an unpromoted resin and must be promoted before use; it must not be combined with amine-based room-temperature curing agents used for epoxy systems, because tertiary amines can destabilize methyl ethyl ketone peroxide and produce gas evolution. The resin should be stored in sealed vessels at 5–25°C away from direct sunlight; storage beyond 6 months may increase viscosity by 10–20% and accelerate gel time drift. Delivery in unheated tankers during winter requires viscosity verification before transfer; heating above 40°C or local hot spots can initiate thermal polymerization. In open mold operations, ventilation must be sufficient to keep styrene monomer vapour below the applicable occupational exposure limit, and waste catalyst-promoted resin must be spread in thin layers to avoid high exotherm in collection containers. Published data for the specific use of Avicor 325 with carbon veil in 1.5 mm conductive linings is limited; design validation for electrostatic dissipative service therefore requires project-specific testing.
