In commercial vinyl acetate emulsion polymerization, the selection of a protective colloid governs particle nucleation rate, grafted shell morphology, and the shear response of the finished latex. Partially hydrolyzed polyvinyl alcohol CCP BF-17, with a degree of hydrolysis between 86.5 and 89.0 mol% and a 4 % aqueous solution viscosity of 25–30 mPa·s at 20 °C per ISO 3105, occupies a narrow performance corridor where residual hydrophobic acetate blocks adsorb strongly onto poly(vinyl acetate) (PVAc) cores while sufficient hydroxyl density maintains colloidal stability against high-shear coalescence. When processed in baffled glass-lined reactors equipped with anchor or pitched-blade impellers operating at 80–150 rpm, BF-17 is typically pre-dissolved in deionized water at 10–15 % solids and charged into the aqueous phase alongside a nonionic surfactant such as alkylphenol ethoxylate or alcohol ethoxylate at a colloid-to-monomer ratio of 4–8 phr. The continuous phase temperature is ramped to 72–78 °C before the commencement of a staged vinyl acetate monomer feed; redox initiation with persulfate–bisulfite or thermal initiation with ammonium persulfate at 0.2–0.5 % by monomer weight triggers grafting of PVAc chains onto the BF-17 backbone. A well-characterized processing hazard arises when the batch temperature overshoots 82 °C: unreacted BF-17 undergoes thermal-accelerated acetal formation with residual aldehyde impurities, producing a transient viscosity spike that collapses the agitator’s pumping capacity and yields a coagulum-prone dispersion. Post-polymerization the latex is cooled to 35 °C, adjusted to pH 4.5–5.5 with sodium bicarbonate, and filtered through 180 µm mesh bags. Finished adhesives compounded from this base latex, often plasticized with dibutyl phthalate or benzoate esters, comply with FDA 21 CFR 175.105 for indirect food-contact adhesive applications in folding carton side-seam gluing and spiral-wound tube lamination.
Where BF-17 Replaces Cold-Water-Swellable Starch in Alkaline Fine Paper Surface Sizing
Surface-sizing operations on woodfree uncoated fine paper machines running at 1200–1600 m/min impose contradictory demands on the film former: the solution must penetrate the base sheet sufficiently to anchor surface fibrils yet must not dewater so rapidly that it starves the metering nip. Combined size press formulations containing CCP BF-17 at 2–6 % solution concentration, blended with oxidized corn starch at a dry-weight ratio between 1:4 and 1:9, are prepared in jet cookers at 95–105 °C and subsequently cooled to an application temperature of 55–65 °C. The intrinsic film elongation of BF-17, measured at 150–200 % on an Instron tensile frame per ASTM D882-18, reduces picking velocity on offset printing blankets compared with starch-only formulations, as confirmed by IGT pick resistance tests exceeding 1.8 m/s on 80 gsm stock. Dosing is controlled by Coriolis mass flow meters to maintain a dry pick-up of 0.5–1.8 kg BF-17 per metric ton of paper. Because BF-17’s lower molecular weight fraction migrates into the substrate during the wet-stack phase, the delayed film formation at the air-paper interface produces a more uniform pore-sealing effect without the film-splitting pattern observable with fully hydrolyzed grades. Compliance with the German BfR Recommendation XXXVI for paper and board intended for food contact and with the European standard EN 645 for cold-water extractables ensures that reels produced with this surface treatment are acceptable for bakery bag and confectionary overwrap converting lines. A known operational boundary is the size-press solids limit: above 8 % total solids, the low-shear Brookfield viscosity of the BF-17/starch blend at 60 °C exceeds 120 mPa·s, causing misting at the film-split point and uneven cross-web coat weight profiles.
On high-speed warp sizing frames for spun polyester and polyester–cotton blend yarns, the abrasion resistance delivered by a size film directly correlates with the cohesive energy density of the hydroxyl-rich interphase. BF-17 at 88 mol% hydrolysis degree generates a semi-crystalline film that is sufficiently water-soluble to permit complete desizing in 70–80 °C baths containing 0.5 % α-amylase, yet resistant enough to cyclic bending at shed crossing points to maintain weaving efficiency above 93 % on air-jet looms running at 800 rpm. The size paste is formulated by dispersing BF-17 granules in cold water under high-shear dissolution at 1500 rpm within a stainless steel cooker, then heating to 92–98 °C for 30 minutes to eliminate microgel particles. A typical recipe for a 40 Ne combed cotton warp sheet combines BF-17 at 5–7 % dry weight, a low-viscosity hydroxypropyl starch at 2–3 %, and a polyacrylate size for cohesion at 0.5–1.0 %, applied at a size-box temperature of 85–88 °C and a squeeze-roll pressure of 12–16 kN/m to achieve an add-on of 8–12 %. Warp yarns sized with this formula and dried over seven-cylinder can dryers with a surface temperature profile decreasing from 130 °C to 105 °C exhibit hairiness values measured on a Zweigle tester below 3.0 hairs per 100 m for hair lengths exceeding 3 mm. The sized beam is compatible with subsequent enzymatic desizing per ISO 105-C06 testing protocols, and the mill effluent biological oxygen demand remains within discharge permits when the desize wash water is treated in an activated sludge basin. Pre-drying the granular BF-17 at 60 °C before hopper metering is mandatory whenever ambient relative humidity exceeds 65 % to prevent bridging in the pneumatically conveyed feed line.
How Does the Grafting Density of BF-17 Govern Critical Solids Content in Tile Adhesive Dispersions?
Cementitious thin-bed tile adhesives classified under EN 12004 demand a rheology modifier that extends open time without retarding C₃S hydration or degrading tensile bond strength after heat aging. BF-17 is dry-blended at 0.25–0.50 % by weight of the total powder mix, which comprises ordinary Portland cement (CEM I 52.5R), silica sand (0.1–0.5 mm), calcium formate accelerator at 0.3–0.8 %, and a cellulose ether co-binder such as methyl hydroxyethyl cellulose. During the forced-action mechanical mixing with 24–28 L water per 100 kg dry powder in a paddle mixer operating at 300 rpm, BF-17 dissolves over a 90–120 second window, contributing an immediate structured yield stress that prevents slump on vertical substrates while the cellulose ether hydrates more slowly to build longer-term water retention. The 28-day compressive strength measured on prisms cured at 23 °C/50 % RH per EN 196-1 remains within 12–15 MPa compared to 14–16 MPa for the unmodified control, an acceptable reduction given the gain in static shear adhesion beyond 1.5 N/mm² after 6 hours of open time. An incompatibility alert: combinations of BF-17 with zinc stearate water-repellent additives at more than 1.0 % dosage result in formation of a gelatinous zinc–PVOH complex that severely retards Vicat initial set beyond 12 hours and produces a chalky surface layer under trowel finishing. The dry blend must be stored in polyethylene-lined paper sacks below 40 °C; stack compression loading exceeding 8 pallets can cold-flow the BF-17 granules and generate agglomerated lumps that resist redispersion on the jobsite.
Water-soluble film for unit-dose detergent and agrochemical packaging demands a PVOH grade that balances cold-water depolymerization with sufficient melt strength to survive blown-film bubble stability at high draw-down ratios. BF-17 with its 88 mol% alcoholysis and medium degree of polymerization is compounded with 12–20 phr of a plasticizer system—typically a combination of glycerol, sorbitol, and trimethylolpropane—along with 0.5–1.0 % stearamide slip agent and 0.1–0.3 % phenolic antioxidant in a co-rotating twin-screw extruder having an L/D = 40 and equipped with moderate-shear kneading blocks. The barrel temperature profile is tightly controlled from the feed throat at 60 °C to the die at 175–195 °C; excursions above 205 °C initiate dehydrochlorination-derived chromophore formation, which discolors the film and lowers its tear propagation resistance. Melt exiting a spiral mandrel die with a 0.8–1.2 mm die gap is blown at a blow-up ratio of 2.5:1 to 3.0:1 and quenched in a dual-lip air ring delivering air at 10–15 °C. The resulting 40–80 µm film displays an Elmendorf tear of 800–1200 mN in machine direction per ISO 6383-2:1983 and dissolves completely within 120 seconds in deionized water at 10 °C, a dissolution profile compliant with the forthcoming European Detergents Regulation for soluble sachets. Blocking tendency on the roll is mitigated by maintaining a carbonyl content below 0.15 % as measured by hydroxylamine hydrochloride titration; finished film reels are conditioned at 22–25 °C and 50 % RH for 24 hours before slitting to prevent telescoping. The film is accepted under the EDANA voluntary stewardship framework for dissolvable packaging, provided the final conversion into pods is verified to meet ASTM D6400 disintegration criteria for industrial compostability.
Remoistenable adhesives based on BF-17 exploit the inversion of tack that occurs when a dried PVOH film absorbs a critical amount of liquid water while retaining sufficient cohesive strength to resist paper fiber rupture under peel stress. Concentrated solutions at 15–25 % solids are prepared by dispersing BF-17 in cold water, then heating to 90–95 °C under slow-sweep agitation for 40 minutes until optical clarity is achieved, after which 3–5 % polyethylene glycol 400 and 0.1 % sodium benzoate preservative are stirred in. The adhesive is applied via engraved gravure rolls at 3–5 g/m² dry coat weight onto pre-gummed paper facestock, dried in a three-zone hot-air tunnel with zone temperatures of 80 °C, 110 °C, and 50 °C, and then conditioned to a moisture content of 6–8 % before sheeting. The result is a non-blocking coated surface that develops full wet-tack adhesion within 2–4 seconds when dampened with a water-saturated foam roller, reaching a bond strength greater than the internal bond of 80 gsm kraft envelope stock as determined by TAPPI T 833 pm-19. This requirement, coupled with the need for rapid remoistenability at sip-and-seal converting speeds above 400 envelopes per minute, defines the operating window: BF-17 shipments destined for envelope converters must have a volatile content below 4.5 % and a cold-water solubles fraction above 99.0 % to ensure no undissolved residue blocks the precision orifice coating heads. Storage in unconditioned warehouses in tropical climates leads to hydrolytic molecular weight reduction; a lot retained in a sealed bulk container at 38 °C/85 % RH for 90 days exhibited an 11 % drop in solution viscosity, moving the product outside the specification needed for edge-penetration control on lick-and-stick label stock.
A defining challenge in water-soluble polymer selection for high-speed textile warp sizing and paper surface treatment is balancing film flexibility against aqueous solubility at moderate temperatures. CCP PVA BF-17 occupies a narrow performance band among partially hydrolyzed polyvinyl alcohol grades, offering a viscosity of 16.5–19.5 mPa·s (4 % aqueous solution at 20 °C, determined per JIS K 6726), a degree of hydrolysis of 86.5–89.0 mol%, and a maximum ash content of 0.5 % as Na2O. Unlike fully hydrolyzed counterparts that demand dissolution temperatures exceeding 90 °C with extended stirring, BF-17 achieves complete dissolution at 65–75 °C under moderate agitation, a process window derived from its residual acetate content of 11–13.5 mol%. The molecular weight distribution, inferred from the specified viscosity, corresponds to a weight-average molecular weight Mw between 25,000 and 35,000 g/mol, situating the grade between low-viscosity specialty coating PVAs and higher-viscosity grades used for structural adhesives.
Film Elasticity Under What Hygrothermal Aging Conditions Justifies the Acetate Retention Range?
The 86.5–89.0 mol% hydrolysis range is not an arbitrary specification. When a cast film of BF-17 is equilibrated at 23 °C and 50 % RH, tensile elongation at break values between 150 % and 200 % are typical (tested per ISO 527-3 at 200 mm/min). Residual acetate groups disrupt intermolecular hydrogen bonding, reducing crystallinity from the 45–55 % range observed in fully hydrolyzed (98–99 mol%) grades to approximately 25–30 % for BF-17. The resultant amorphous phase dominance imparts flexibility without requiring external plasticizers—an operational advantage in warp sizing formulations where migration of low-molecular-weight plasticizers onto loom reed wires causes lubricant film breakdown. However, at relative humidity above 70 %, the film absorbs moisture mass up to 10–12 % of its dry weight, lowering the glass transition temperature (Tg) from 58–62 °C (dry) to approximately 15–20 °C. In paper coating calendars operating with roll surface temperatures of 80–110 °C, this plasticization is sufficient to prevent fibre picking, yet the film retains enough cohesive strength to avoid transfer to the calender rolls.
During adhesive compounding for porous substrates, BF-17 interacts non-ideally with boric acid and glyoxal crosslinkers. The relatively high molecular weight compared to low-viscosity grades (e.g.,
4–7 mPa·s types) lengthens the open time by
20–40 seconds under
25 °C,
60 % RH conditions, as measured by a Brookfield viscometer spindle #3 at
50 rpm. Yet, the partial hydrolysis avoids the rapid gelation encountered when fully hydrolyzed PVA is combined with borate ions at alkaline pH—a processing pitfall documented on corrugated board laminators with pot lives falling below
15 minutes at pH
9.5. For BF-17, the borax gel point occurs at a higher borax/PVA mass ratio, reflecting the shielding effect of residual acetate groups on diol complexation sites.
Batch-to-Batch Viscosity Drift and Its Implications for Slashing Creel Speeds
Textile slashing operations running single-end sizing at creel speeds between 300 and 1,200 m/min expose viscosity inconsistencies as tension variation across the warp sheet. CCP PVA BF-17 is manufactured with a viscosity tolerance of ±1.5 mPa·s from lot midpoint, a 8–9 % relative variation that, in a 8 % solids size box maintained at 85 °C, translates to a viscosity fluctuation of ±12 % at application temperature. This fluctuation influences size add-on uniformity: on a 40s Ne cotton yarn processed through a twin-cylinder squeeze nip with a 1.5 bar pneumatic loading, the coefficient of variation (CV%) of add-on across a 200-end section has been recorded at 2.8–3.5 % when the size liquor viscosity varies within this band. By contrast, generic partially hydrolyzed PVA grades with broader viscosity specifications (±3 mPa·s) have yielded CV% values exceeding 5.5 %, leading to end-break rates escalating from 0.3–0.5 breaks per million picks to 1.2–1.8 breaks per million picks on high-speed air-jet looms. These data points, collected on a Tsudakoma ZAX9100 loom running at 720 rpm, underscore the mechanical consequence of molecular weight control during polymerisation.
Differences from fully hydrolyzed PVA extend beyond dissolution temperature. When replacing a 98.5 mol% hydrolysis grade with BF-17 in a warp size formulation, the desizing process on a continuous rope washer requires an enzyme-free oxidative scour with hydrogen peroxide at 0.5 % owb and sodium hydroxide at 0.3 % owb at 60 °C rather than amylase-based desizing. The fully hydrolyzed film’s higher crystallinity and density (1.30 g/cm³ vs. 1.27 g/cm³ for BF-17) resists water penetration, often necessitating a two-stage caustic scour at boil—a route incompatible with delicate blended yarns containing elastane. BF-17’s reduced crystallinity dissolves completely within 20 seconds immersion in water at 40 °C, meeting the rapid-desize demands of specialty fabrics without residual polymer spotting detectable by iodine staining (per AATCC 144).
When Tetrachloroethane Replacement in Wet-Strength Paper Saturants Entrains VOC Compliance Constraints
In the context of replacing solvent-based saturants for wet-strength paper (e.g., vulcanized fibre base stock), the migration from tetrachloroethane-laden phenolic solutions to aqueous PVA saturants necessitates re-evaluation of film water resistance. BF-17, with its partial hydrolysis, possesses a cold-water solubility threshold: at 10 °C, dissolution takes 8–12 minutes, whereas a 98 mol% hydrolyzed grade remains undissolved after 60 minutes. This facilitates aqueous processing but compromises immediate wet strength. To counteract this, post-treatment with dimethyloldihydroxyethyleneurea (DMDHEU) at 5 % on PVA weight, cured at 140 °C for 2 minutes, yields a wet tensile index retention of 35–40 % (compared to 20–25 % without crosslinking), as measured per ISO 3781. The performance gap relative to fully hydrolyzed grades persists: a 99 mol% PVA treated identically achieves 55–60 % wet retention, so the selection of BF-17 is justified only where resolubility in cold water is a process requirement, not an end-use liability. This trade-off is critical in temporary protective films for metal stamping, where hot-water stripping at 70 °C is undesirable due to thermal distortion of stamped aluminium panels.
The following table contrasts BF-17 with two extremes in the PVA product spectrum—a low-viscosity, high-hydrolysis coating grade and a high-viscosity, fully hydrolyzed structural adhesive grade—across parameters relevant to aqueous solubility and film mechanics.
| Property | CCP PVA BF-17 | Low-MW Fully Hydrolyzed Grade (Comparison A) | High-MW Fully Hydrolyzed Grade (Comparison B) |
|---|
| Viscosity 4 % aq., 20 °C (mPa·s) | 16.5–19.5 | 4.5–6.0 | 40.0–50.0 |
| Hydrolysis (mol%) | 86.5–89.0 | 98.0–99.0 | 98.5–99.5 |
| Dissolution temp. range (°C) | 65–75 | 90–98 | ≥95 |
| Crystalline melting onset (°C, DSC, 10 K/min) | 165–175 | 220–228 | 225–232 |
| Film elongation at break, 23 °C/50 % RH (%) | 150–200 | 20–40 | 80–120 |
| Water absorption at 80 % RH (% wt gain) | 8–10 | 14–18 | 18–22 |
| Typical application window | Controlled-solubility warp size, paper coating binder, temporary protective film | High-solids low-viscosity coating, textile finishing where film stiffness required | Structural wood adhesive, high-strength emulsion polymerisation colloid |
Extrusion Compounding with Starch Thermoplastics: A Kinetic Miscibility Gap
A non-intuitive processing limitation emerges when BF-17 is co-compounded with hydroxypropylated high-amylose corn starch in a corotating twin-screw extruder with an L/D 40 configuration and a 25 mm screw diameter. The starch–PVA melt blend, plasticized with a 30 % (w/w total polymer) glycerol/water mixture, exhibits a phase-inversion composition between 40 wt% and 55 wt% PVA. At 40 wt% BF-17, the continuous starch phase encapsulates PVA domains, and the melt viscosity at 130 °C and 100 s⁻¹ shear is 800–1,200 Pa·s. Increasing PVA to 55 wt% inverts the morphology, dropping viscosity to 300–500 Pa·s. Within this transition zone, strand pelletizing becomes unstable: surface tearing frequency rises, and pellet bulk density CV% exceeds 15 %. The processing window for uniform pellets is consequently restricted to PVA loadings below 35 wt% or above 60 wt%, a constraint not present when a lower-viscosity PVA (e.g., 4–6 mPa·s) is used, where phase inversion occurs below 25 wt%. This difference directly affects the formulation cost structure in biodegradable blown film applications because BF-17, at the required higher loading to achieve continuous PVA phase, increases raw material expense while improving film puncture resistance by 40–50 % (tested per ASTM F1306, 0.5 mm film thickness) compared to the low-MW PVA/starch system.
Published data for this specific configuration is limited; however, rheo-optical observations on a parallel-plate setup combined with online near-infrared spectroscopy have confirmed that the acetate groups in BF-17 provide greater compatibility with the hydroxypropyl substituents than fully hydrolyzed PVA, which separates into macroscopic aggregates rather than deformed droplets under identical extrusion conditions.
In paper coating binder formulations, BF-17 competes not only with other PVA grades but with styrene-butadiene latexes. A pilot coater trial on a cylindrical laboratory coater (CLC-6000, SimuTech) at 800 m/min with a bent blade configuration deposited a coat weight of 8–10 g/m² per side on a 48 g/m² base paper. At BF-17 latex replacement levels of 30 % of the dry binder, the IGT dry pick resistance (per ISO 3783) increased from 2.8 m/s to 3.4 m/s, while the OBA (optical brightening agent) carrier capacity, assessed by CIE whiteness (D65/10°), rose by 3.2 points because of reduced quenching by aromatic latex monomers. The offset is a slight loss in wet pick resistance—a consequence of BF-17’s cold-water sensitivity—that precludes its use in lithographic offset grades printed with high-dampening fountain solutions unless a latent crosslinker (glyoxal-based, 0.15 % on binder) is added to the coating colour.
Process Safety and Regulatory Footprint in Indirect Food Contact
BF-17 complies with the compositional requirements of FDA 21 CFR 176.170 (Components of paper and paperboard in contact with aqueous and fatty foods) and 176.180 (Components of paper and paperboard in contact with dry food) when used as a surface sizing or coating binder, provided the extraction maxima for total non-volatile residue do not exceed 0.5 mg/in² under the intended conditions of use. Residual vinyl acetate monomer is specified to be below 5 ppm, consistent with EU directive 10/2011 overall migration limits for plastic food contact materials. The grade is delivered in granular form with a bulk density of 0.55–0.65 g/cm³ and a moisture content below 5.0 %, and the manufacturer recommends pre-drying to below 0.3 % moisture before melt processing to avoid hydrolytic degradation in an extruder barrel—a step frequently neglected on production lines leading to viscosity reductions of 10–15 % after a single pass.
The difference between BF-17 and its close analogue, a 87–89 mol% hydrolysis PVA with a viscosity of 20–25 mPa·s (often designated BF-20 in the same series), manifests in the spray-drying agglomeration tendency. The lower molecular weight of BF-17 reduces inter-particle bridging during fluidized-bed rehumidification, yielding a finer agglomerate particle size distribution (D50 of 180–220 µm vs. 280–350 µm for the higher-viscosity variant) and faster cold-water dispersion—a meaningful parameter in remote-site oilfield cementing operations where PVA serves as a fluid-loss additive pre-hydrated in batch mixers with limited shear. In such applications, undispersed “fisheyes” constitute a workover risk; BF-17’s cold-water dispersibility reduces fisheye counts from 12–18 per 100 cm² (BF-20 grade) to 3–5 per 100 cm² when screened through a 100-mesh sieve after 15 minutes of hydration at 10 °C in fresh water.
| Test Standard | Parameter Measured | CCP PVA BF-17 Typical Result |
|---|
| JIS K 6726 | Viscosity, 4 % aq., 20 °C | 18.0 mPa·s |
| JIS K 6726 | Saponification value (hydrolysis) | 88.0 mol% |
| JIS K 6726 | Ash content (as Na₂O) | 0.3 % |
| JIS K 6726 | Volatile matter | 4.2 % |
| ISO 1133-1 (modified) | Melt flow rate (190 °C, 2.16 kg) | Not applicable (decomposes before melt) |
| ISO 11443 | Capillary rheometry at 140 °C, 100 s⁻¹ | 450–550 Pa·s (plasticized with 15 % glycerol) |
The avoidance of heavy-metal catalysts in the polymerisation process is confirmed by an absence of detectable lead, cadmium, mercury, and hexavalent chromium per RoHS directive 2011/65/EU recast Annex II, when analysed by ICP-OES with detection limits of 2 mg/kg. For textile applications governed by OEKO-TEX Standard 100 (product class I–IV), the compound meets the requirement for formaldehyde content below 16 mg/kg and extractable antimony below 30 mg/kg, as it is not synthesized via antimony-catalysed transesterification typical of polyester but via free-radical polymerization of vinyl acetate followed by methanolysis. One incompatibility noted in industrial blending is with amine-functional silane coupling agents (e.g., 3-aminopropyltriethoxysilane), which induce premature deacetylation and crosslinking at alkaline pH during storage of pre-mixes; this necessitates a dual-component feed system when silane-enhanced adhesion to glass fibres is demanded.
Alternative Emulsion Polymerisation Colloid: Differences in Grafting Efficiency
When employed as a protective colloid in vinyl acetate homopolymer emulsion polymerisation, BF-17 yields a grafting efficiency (percentage of PVA permanently bound to PVAc particles via chain transfer) of 25–32 %, as determined by Soxhlet extraction of dried films. Fully hydrolyzed grades of similar viscosity produce grafting efficiencies of 40–50 % due to greater radical abstraction from methine carbons in the absence of acetate steric hindrance. The lower grafting efficiency correlates with an increase in minimum film formation temperature (MFFT) of the resulting emulsion from 12 °C to 17 °C, a shift that complicates low-temperature wood adhesive application in unheated factories. However, the BF-17-stabilized emulsion exhibits superior freeze-thaw stability: after three cycles of -10 °C/25 °C, viscosity change remains within ±10 % of the original, whereas a fully hydrolyzed PVA-stabilized emulsion typically increases in viscosity by 200–400 % or coagulates, owing to the partial solubility of the BF-17 colloid at low temperatures that prevents segregated ice-crystal-induced compression of colloidal particles.
In polymer-modified cement mortars for self-levelling underlayments, BF-17 is added at 0.5–1.5 % by cement weight as a secondary rheology modifier behind a primary cellulose ether. At this dosage, it extends the pot life from 45 minutes to 65 minutes (measured by a slump flow exceeding 200 mm per EN 12706 without additional hydration water) without the severe retardation caused by higher acetate content (85 mol%) PVAs that can delay final set beyond 24 hours. The tensile adhesion strength to a concrete substrate, tested per EN 13813 after 28 days dry curing, reaches 1.5–1.8 MPa, exceeding the 1.0 MPa typical for unmodified cement and approaching the 2.0 MPa achieved with styrene-acrylic redispersible powders, but at a cost reduction and without volatile organic coalescent agents.
