Analysis of the Production Process of Hydroxypropyl Methylcellulose (HPMC) for Putty: Understanding Differences in Substitution Structure and Gelation Temperature from High-Ratio and Low-Ratio Formulations

1 Differences Among Neutral Putty, 821 Putty, and Ordinary Interior Wall Putty

“Neutral putty,” “821 putty,” and “ordinary interior wall putty” are not standard classifications within the same category. Neutral putty is more of a market term formed according to the acidity/alkalinity or cementitious system characteristics of the formulation. 821 putty is more of a market term derived from the evolution of a historical product name. Ordinary interior wall putty is a general term based on application scenarios and performance requirements. In actual product evaluation, the performance categories and testing indicators specified in current interior wall putty product standards should also be considered.

1.1 Neutral Putty

Neutral putty usually refers, in the market, to an interior wall putty system with a pH close to neutral or weakly alkaline. It emphasizes the acid–base characteristics of the formulation system; that is, it does not use strongly alkaline cementitious materials such as white cement or hydrated lime powder as the primary bonding system, and its alkalinity is relatively mild during application and after drying.

1.2 821 Putty

The name “821 putty” is generally traced back to “SG-821 putty.” SG-821 putty was a new type of interior wall leveling material that emerged in the early 1980s. In its early form, it used building gypsum as the main raw material and was combined with additives such as sodium carboxymethyl cellulose (CMC), pregelatinized starch, and retarders. It was used to replace traditional lime paste leveling materials.

As the term spread in the market, “821 putty” gradually evolved from a specific product name into a common term for ordinary non-water-resistant interior wall putty. Today, what the market refers to as 821 putty does not necessarily strictly correspond to the original formulation of early SG-821 putty. Instead, it often broadly refers to ordinary interior wall leveling putty that is easy to apply, easy to sand, relatively low in cost, and relatively weak in water resistance.

1.3 Ordinary Interior Wall Putty

Ordinary interior wall putty is generally used for leveling indoor wall surfaces. It mainly consists of fillers, binders, and additives. Different manufacturers adjust their formulations according to cost, application feel, sandability, strength, and water-resistance requirements. Common systems include:

Type of Putty	Main Characteristics	Key Evaluation Points
821-type ordinary putty	Easy to apply and sand; usually relatively weak in water resistance	Suitable for ordinary interior wall leveling; not suitable for humid environments
Neutral putty	pH close to neutral or weakly alkaline	Relatively mild to substrates and subsequent coatings, but water resistance still needs to be considered
Water-resistant putty	Higher bonding strength and water resistance	Sandability may be poorer than that of 821-type putty, and higher requirements are placed on application feel
Cement-based or hydrated-lime-based putty	Stronger alkalinity, better strength and water resistance	Efflorescence, cracking, and working/open time should be carefully considered

2 Hydroxypropyl Methylcellulose in Putty

2.1 Core Functions of Hydroxypropyl Methylcellulose in Putty

Hydroxypropyl methylcellulose (HPMC) is a commonly used cellulose ether additive in construction putty. In putty systems, HPMC mainly performs four functions:

Function	Practical Significance in Putty
Water retention	Delays rapid water absorption by the substrate, allowing the putty sufficient time to complete powder wetting, cementitious hydration or crystallization hardening, polymer film formation, and interfacial bonding
Thickening	Increases slurry consistency, making the putty less prone to sagging or appearing loose and weak
Improved workability	Improves smoothness during troweling, blade feel, open time, and finishing performance
System stabilization	Reduces the risk of settling, bleeding, agglomeration, and batch-to-batch fluctuation

2.2 HPMC Quality Evaluation in Putty Applications Should Not Be Based on Viscosity Alone

Viscosity mainly reflects the ability of an HPMC aqueous solution to generate flow resistance and consistency. However, putty is a composite system composed of fillers, redispersible polymer powder, inorganic powders, water, and various additives. In actual formulations, the performance of HPMC is influenced by at least the following factors:

Indicator	Influence on Putty Applications
Viscosity	Affects thickening, anti-sagging performance, and the heavy feel during application
Methoxy content	Affects hydrophobic association, thermal gelation tendency, and temperature sensitivity
Hydroxypropyl content	Affects hydrophilicity, solubility, water retention, and gelation temperature
Molecular weight distribution	Affects rheology, blade feel, and application stability
Uniformity of substitution	Affects dissolution rate, insoluble matter, and batch stability
Gelation temperature	Affects consistency change and open time during high-temperature application
Ash and salt content	Affects purity, system stability, and compatibility with other components
Particle size	Affects dry-mix dispersion, dissolution after water addition, and anti-agglomeration performance

The viscosity of HPMC should be reported together with the testing concentration, temperature, instrument, and method. Viscosity values from different manufacturers or measured by different testing methods should not be directly compared. Only under the same testing conditions can viscosity data provide meaningful comparability.

3 HPMC Process: How Refined Cotton, Liquid Alkali, Methyl Chloride, and Propylene Oxide Create Product Differences

3.1 Basic Reaction Route of HPMC

HPMC is usually produced from refined cotton or other high-purity cellulose materials. The cellulose is alkalized with sodium hydroxide solution to activate the hydroxyl groups on the cellulose molecular chains. It then undergoes etherification reactions with methyl chloride and propylene oxide, introducing methyl and hydroxypropyl groups. The final product is obtained after recovery, neutralization, washing, drying, pulverization, and blending.

Stage	Main Function	Influence on Product Quality
Alkalization	Sodium hydroxide swells cellulose and activates hydroxyl groups	Determines reaction uniformity, substitution uniformity, and insoluble matter level
Methylation	Methyl chloride introduces methoxy groups	Affects thermal gelation, thickening efficiency, hydrophobic association, and gelation temperature
Hydroxypropylation	Propylene oxide introduces hydroxypropyl groups	Affects hydrophilicity, solubility, water retention, and open time

3.2 Alkalization Determines Whether the Reaction Can Begin Uniformly

Natural cellulose molecular chains contain a large number of hydroxyl groups, but cellulose itself has many crystalline regions and limited reactivity. Sodium hydroxide causes cellulose to swell and forms alkali cellulose, which is more readily involved in etherification reactions.

If alkalization is insufficient, cellulose swelling will be inadequate. As a result, methyl chloride and propylene oxide will have difficulty penetrating uniformly into the interior of the cellulose, which can easily cause locally insufficient substitution. This may appear as increased insoluble matter, slow dissolution, and a less delicate putty surface. If alkalization is too strong or lasts too long, cellulose molecular chains may degrade, eventually resulting in reduced viscosity, lower water-retention capacity, and insufficient troweling support.

3.3 Methyl Chloride and Propylene Oxide Determine the Substitution Structure

The two key substituent groups in HPMC are methoxy groups and hydroxypropyl groups. Methoxy groups are mainly introduced by methyl chloride, while hydroxypropyl groups are mainly introduced by propylene oxide. Different ratios between the two lead to differences in HPMC solubility in water, thermal gelation behavior, water-retention capacity, and application feel.

Substituent Group	Source	Main Characteristics	Influence on Putty
Methoxy group	Methyl chloride	Relatively hydrophobic and prone to hydrophobic association	Enhances thickening efficiency, structural feel, and temperature sensitivity
Hydroxypropyl group	Propylene oxide	Stronger hydrophilicity and steric hindrance	Improves dissolution, water retention, and open time, and tends to increase gelation temperature

4 High-Ratio and Low-Ratio Formulations: Influence of HPMC Process Ratios on Substitution Structure and Gelation Temperature

4.1 Ratio Differences Are Reflected in Etherifying Agent Dosage and Reaction Time

In HPMC production, the core differences between high-ratio and low-ratio formulations should be analyzed based on specific process parameters and product structure data. Taking a set of comparative HPMC process data as an example, when the refined cotton input is the same, changes in the dosages of methyl chloride and propylene oxide and in reaction time ultimately correspond to different methoxy contents, hydroxypropyl contents, and gelation temperatures.

Item	High Ratio	Low Ratio	Corresponding Relationship
Refined cotton	750 kg	750 kg	Same cellulose backbone input
Methyl chloride	800 kg	600 kg	Related to methoxy group introduction
Propylene oxide	320 kg	200 kg	Related to hydroxypropyl group introduction
Reaction time	6 h	4 h	Different etherification reaction times
Methoxy content	24%	19%	Higher methoxy content in the high-ratio sample
Hydroxypropyl content	11%	9%	Higher hydroxypropyl content in the high-ratio sample
Gelation temperature	58–62°C	73–78°C	Lower gelation temperature in the high-ratio sample
Ash content	No significant difference	No significant difference	Similar post-treatment residue level
Viscosity	No significant difference	No significant difference	Similar molecular weight and thickening capacity
Moisture	No significant difference	No significant difference	Similar drying and storage status

From this set of data, the differences between the high-ratio and low-ratio samples are concentrated in substitution structure and thermal response characteristics. When ash content, viscosity, and moisture are close, the products may still show different hydration states, water-retention capacities, temperature sensitivities, and application feels in the putty system due to differences in methoxy content, hydroxypropyl content, and gelation temperature.

4.2 Methyl Chloride Dosage Significantly Affects Methoxy Group Introduction

Methyl chloride is the main source of methoxy groups in HPMC. In this set of data, the methyl chloride dosage is 800 kg for the high-ratio sample and 600 kg for the low-ratio sample, a difference of 200 kg. In the corresponding finished-product indicators, the methoxy content is 24% for the high-ratio sample and 19% for the low-ratio sample.

As methoxy content increases, the hydrophobic substituted structures in HPMC molecules also increase. During heating of an HPMC aqueous solution, the hydration layer around the molecular chains gradually weakens, hydrophobic association becomes stronger, and the system begins to exhibit thermal gelation behavior. When methoxy content is higher, the temperature range for thermal association generally shifts downward, and the gelation temperature decreases accordingly.

In this set of data, the methoxy content of the high-ratio sample is 5 percentage points higher than that of the low-ratio sample, while the gelation temperature decreases from 73–78°C in the low-ratio sample to 58–62°C in the high-ratio sample. This result indicates that changes in methoxy content have a clear influence on gelation temperature.

4.3 Propylene Oxide Dosage Determines the Level of Hydroxypropyl Group Introduction

Propylene oxide is the main source of hydroxypropyl groups in HPMC. In this set of data, the propylene oxide dosage is 320 kg for the high-ratio sample and 200 kg for the low-ratio sample, a difference of 120 kg. In the corresponding finished-product indicators, the hydroxypropyl content is 11% for the high-ratio sample and 9% for the low-ratio sample.

Hydroxypropyl groups have hydrophilicity and steric hindrance effects, which influence HPMC dissolution, hydration, water retention, and molecular chain association. When hydroxypropyl content increases, the hydration ability and dissolution state of HPMC change, affecting open time, water-retention stability, and application feel in putty.

In this set of data, the high-ratio sample has both higher methoxy content and higher hydroxypropyl content, yet its gelation temperature is significantly lower than that of the low-ratio sample. Based on this group of samples, it can be judged that the increase in methoxy content may be one important factor contributing to the decrease in gelation temperature. However, gelation temperature is also affected by hydroxypropyl content, substitution uniformity, molecular weight, salt content, solution concentration, and testing method. Therefore, when analyzing the structure of HPMC, methoxy content, hydroxypropyl content, gelation temperature, and actual application performance should be evaluated together, rather than judging from any single indicator in isolation.

4.4 Reaction Time Corresponds to the Target Substituent Content

The reaction time is 6 hours for the high-ratio sample and 4 hours for the low-ratio sample. The difference in reaction time is related to the target substituent content.

The high-ratio sample uses higher dosages of methyl chloride and propylene oxide, together with a longer reaction time, resulting in a finished product with 24% methoxy content and 11% hydroxypropyl content. The low-ratio sample uses lower dosages of methyl chloride and propylene oxide, with a reaction time of 4 hours, resulting in a finished product with 19% methoxy content and 9% hydroxypropyl content.

Reaction time mainly serves the completion degree of the etherification reaction and the target substitution structure. Viscosity is mainly related to the length of cellulose molecular chains, molecular weight distribution, and degree of degradation. Methoxy and hydroxypropyl contents reflect the substitution structure. In this set of data, the viscosities of the high-ratio and low-ratio samples are close, indicating that their thickening capacities are in a similar range, while their substituent structures are significantly different.

4.5 Gelation Temperature Reflects Differences in Substitution Structure

Based on this set of data, the methoxy content of the high-ratio sample is 5 percentage points higher than that of the low-ratio sample, and the gelation temperature decreases from 73–78°C in the low-ratio sample to 58–62°C in the high-ratio sample. This result indicates that, in this group of samples, differences in substitution structure are clearly associated with changes in gelation temperature.

Indicator	High Ratio	Low Ratio
Methoxy content	24%	19%
Hydroxypropyl content	11%	9%
Gelation temperature	58–62°C	73–78°C
Structural characteristics	Higher methoxy content, higher hydroxypropyl content, lower gelation temperature	Lower methoxy content, lower hydroxypropyl content, higher gelation temperature
Key putty observation points	Consistency change after temperature increase, blade sticking, finishing behavior, and open time	Hydration stability under high-temperature conditions, thickening support, and water-retention capacity

The gelation temperature of HPMC reflects the temperature range in which its aqueous solution changes from a hydrated dispersion state to a thermally associated state during heating. For putty applications, the application temperature usually does not reach the complete gelation state, but gelation temperature can still reflect the product’s sensitivity to temperature changes.

The high-ratio sample has a lower gelation temperature, making it more likely to show changes in hydration state and consistency as temperature rises. The low-ratio sample has a higher gelation temperature, allowing its hydration state to remain stable over a higher temperature range for a longer period. The performance of the two samples in putty should be evaluated together with substrate water absorption, application temperature, powder composition, polymer powder system, and HPMC dosage.

4.6 When Conventional Indicators Are Similar, Structural Indicators Should Be Compared More Closely

Ash content mainly reflects inorganic residue and the level of post-treatment. Moisture reflects drying and storage status. Viscosity reflects the thickening capacity of an aqueous solution and the molecular weight level. In this set of data, ash content, viscosity, and moisture are close, indicating that the basic quality indicators are at a similar level. When the basic indicators are close, methoxy content, hydroxypropyl content, and gelation temperature become key indicators for distinguishing product structure and application performance.

Indicator Type	Key Indicators	What They Reflect
Basic quality indicators	Moisture, ash content, pH	Post-treatment, purity, and storage status
Thickening indicator	Viscosity	Molecular weight level and aqueous-solution thickening capacity
Substitution structure indicators	Methoxy content, hydroxypropyl content	Etherification structure, hydration capacity, and hydrophobic association tendency
Thermal response indicator	Gelation temperature	Temperature sensitivity and thermal association behavior

4.7 Application Judgment for Putty Formulations

Based on this set of process data, the selection between high-ratio and low-ratio products should be determined by the putty formulation system. 821-type ordinary putty, neutral putty, hydrated-lime-based putty, gypsum-based putty, and water-resistant putty differ in powder composition, pH conditions, water absorption rate, and binder system. Therefore, their requirements for HPMC substitution structure and gelation temperature are also different. In actual comparison, the same base putty formulation can be used for testing, with attention focused on the following items:

Test Item	Evaluation Content
Initial consistency	Thickening speed after water addition and initial application state
Consistency change after standing	Open time and hydration stability
Application feel after high-temperature storage	Temperature sensitivity, blade sticking, and finishing changes
Troweling smoothness	Blade feel, dragging, and surface fineness
Water retention	Water loss rate under highly absorbent substrate conditions
Sandability	Hardness after drying, chalking, and sanding resistance
Surface condition	Dissolution and dispersion, graininess, and powder compatibility

High-ratio and low-ratio samples represent differences formed within a specific process system due to different etherifying agent dosages, reaction times, and target substitution structures. When viscosity, ash content, and moisture are close, methoxy content, hydroxypropyl content, substitution uniformity, and gelation temperature may become key factors affecting putty application feel, water retention, open time, and temperature sensitivity.

5 Classification Tables of Representative Chemicals Related to Hydroxypropyl Methylcellulose Formulation for Putty

Table 1 Cellulose Ethers, Starch Ethers, and Structural Reference Materials

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Hydroxypropyl methylcellulose ether	9004-65-3	H1506257	Hydroxypropyl methylcellulose (HPMC)	Substitution type 2910; viscosity: 400 mPa·s; methoxy: 28–30%; hydroxypropyl: 7.0–12%	A representative sample for studies on water retention, thickening, open time, gelation temperature, and substituent structure in putty. It can be used for correlation experiments between methoxy/hydroxypropyl groups and application performance.
2208-type hydroxypropyl methylcellulose ether	9004-65-3	H108824	Hydroxypropyl methylcellulose (HPMC)	Substitution type 2208; viscosity: 4000 mPa·s; methoxy: 19–24%; hydroxypropyl: 4.0–12%	2208-substitution-type HPMC. Its methoxy and hydroxypropyl ranges are suitable for structural comparison between low-gelation-temperature and high-gelation-temperature HPMC. It can be used for correlation studies on putty water retention, thickening, open time, gelation temperature, and application feel.
Cellulose backbone raw material	9004-34-6	C434462	Cellulose	Microcrystalline powder	A backbone reference material for the etherification reaction of hydroxypropyl methylcellulose. It can be used to study cellulose alkalization, swelling, substitution reactions, and the influence of raw material structure.
Methyl cellulose ether	9004-67-5	M759806	Methyl cellulose (MC)	8–18 mPa·s	A methyl-substituted cellulose ether. It can be used in comparative experiments on methoxy structure, aqueous-solution thickening, thermal gelation temperature, and structural differences from HPMC.
Methyl hydroxyethyl cellulose ether	9032-42-2	M498720	Methyl 2-hydroxyethyl cellulose	Viscosity: 70,000–80,000 mPa·s, 2% in H₂O at 20°C	A cellulose ether with combined methyl and hydroxyethyl substitution. It can be used in comparative experiments on water retention, thickening, rheology, and temperature stability in construction putty.
Hydroxyethyl cellulose ether	9004-62-0	H434475	2-Hydroxyethyl cellulose (HEC)	Average Mw ~380,000	A hydroxyethyl-substituted cellulose ether. It can be used in comparative experiments on thickening, solubility, rheological behavior in aqueous systems, and compatibility with putty additives.
Hydroxypropyl cellulose ether	9004-64-2	H753230	Hydroxypropyl cellulose (HPC)	Viscosity: 4000–6500 mPa·s, 2% aqueous solution at 20°C	A hydroxypropyl-substituted cellulose ether. It can be used to study the influence of hydroxypropyl structure on water solubility, viscosity, water retention, and temperature response.
Sodium carboxymethyl cellulose	9004-32-4	C104986	Sodium carboxymethyl cellulose (CMC)	Viscosity: 1000–1400 mPa·s; USP grade	An anionic cellulose ether. It can be used in comparative experiments on water retention and thickening in 821-type putty, traditional putty additives, and differences from nonionic HPMC systems.
Ethyl cellulose ether	9004-57-3	E110667	Ethyl cellulose (EC)	Chemically pure (CP)	A hydrophobic ethyl-substituted cellulose ether. It can be used to study the hydrophobicity, film-forming properties, and water-solubility differences of cellulose ether substituents.
Hydroxypropyl starch ether	9049-76-7	H304935	Hydroxypropyl starch ether	Viscosity of 5% aqueous solution at 20°C: 500–20,000 mPa·s	A starch ether workability modifier. It can be used to study anti-sagging performance, troweling feel, thixotropy, and synergistic effects with HPMC in putty.
Natural starch material	9005-25-8	S116030	Corn starch	Reagent grade	A natural polysaccharide material. It can be used for studies on starch modification, pregelatinization treatment, thickening/filling, and low-cost formulation design in 821-type putty.

Table 2 Reagents for HPMC Synthesis, Post-Treatment, and Process Analysis

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Cellulose alkalization reagent	1310-73-2	S111498	Sodium hydroxide	Guaranteed reagent, ≥96%	A key reagent for cellulose alkalization. It can be used to study alkalization degree, cellulose swelling, the starting point of substitution reactions, and the risk of molecular chain degradation.
Methylation reagent analytical standard	74-87-3	C298669	Methyl chloride standard solution	100 mg/L, in purge-and-trap methanol solution	An analytical standard for methyl chloride. It can be used for monitoring methylation processes, residual detection, and the development of analytical methods for volatile components.
Hydroxypropylation reagent	75-56-9	P109311	Propylene oxide	≥99.5% (GC)	A reagent for introducing hydroxypropyl groups. It can be used to study ring-opening etherification of propylene oxide, regulation of hydroxypropyl content, and the relationship between HPMC dissolution and water retention.
Alcohol reaction medium	67-63-0	I292350	Isopropanol (IPA)	≥99%	An alcohol solvent. It can be used in experiments on cellulose ether dispersion, washing, solvent replacement, and the influence of water content in the reaction medium.
Anhydrous tertiary alcohol solvent	75-65-0	T119717	tert-Butanol	Anhydrous grade, ≥99.5%	A tertiary alcohol solvent. It can be used in experiments on anhydrous alcohol media, polymer swelling environments, and solvent effects in cellulose ether preparation.
Anhydrous aromatic hydrocarbon solvent	108-88-3	T399633	Toluene (regulated precursor chemical)	Anhydrous grade, ≥99.8%	A nonpolar anhydrous solvent. It can be used in comparative experiments on polymer swelling, extraction, control of water content in reaction media, and non-aqueous systems.
Acidic neutralization reagent	7647-01-0	H485680	Fuming hydrochloric acid, 37% (regulated precursor chemical)	Guaranteed reagent, suitable for analysis, max. 0.001 ppm Hg	An acidic neutralization reagent. It can be used in experiments on cellulose ether post-treatment neutralization, ash treatment, acid–base stability, and the influence of pH conditions.
Alkaline pH adjustment reagent	1336-21-6	A112077	Ammonia solution	Guaranteed reagent, 25–28%	An alkaline aqueous pH adjustment reagent. It can be used in experiments on pH adjustment in putty systems, additive compatibility, and acid–base adaptability of neutral putty.

Table 3 Putty Fillers, Cementitious Materials, and Inorganic Rheology Materials

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Main carbonate filler	471-34-1	C432744	Calcium carbonate	Anhydrous grade, ACS, ≥99%	A main filler for putty. It can be used to study the relationship among powder water absorption, particle size, HPMC dosage, sandability, and water-retention requirements.
Layered silicate filler	1332-58-7	K299133	Kaolin	Filler grade; kaolinite content ≥80%	A layered silicate filler. It can be used to study putty suspension stability, troweling fineness, water absorption, and powder compatibility.
Plate-like silicate filler	14807-96-6	T109493	Talc powder	Pharmaceutical grade, PharmPure™, ≥325 mesh	A plate-like silicate filler. It can be used in experiments on troweling lubricity, surface fineness, sandability, and powder packing structure.
White pigment/filler	13463-67-7	T431947	Titanium dioxide (IV)	Premium grade, ≥99%	A white high-refractive-index pigment/filler. It can be used to study putty whiteness, hiding power, dispersion, and the influence of HPMC on pigment/filler suspension.
Nano silica filler	7631-86-9	S433694	Silicon dioxide	Nanoparticles, mesoporous; outer diameter 450–550 nm, pore size 2–4 nm	A nano-mesoporous inorganic filler. It can be used in experiments on slurry thixotropy, adsorption, thickening synergy, and structural strength.
Organobentonite rheology additive	1302-78-9	B102861	Bentonite	Bentone SD-2, suitable for medium- to high-polarity solvents	An organically modified layered silicate rheology additive. It can be used to study thixotropy, suspension, and filler network structure in medium- to high-polarity solvent systems.
Hemihydrate gypsum cementitious material	10034-76-1	C302031	Calcium sulfate hemihydrate	≥97%	A cementitious material for gypsum-based putty. It can be used in experiments on setting time, retarder effects, HPMC water-retention requirements, and early strength.
Dihydrate gypsum reference material	10101-41-4	C101881	Calcium sulfate dihydrate	ACS, ≥98%	A reference material for gypsum hydration products. It can be used to study hemihydrate gypsum hydration, crystal structure, and stability of gypsum-based putty.
Hydrated-lime-based alkaline cementitious material	1305-62-0	C101986	Calcium hydroxide	AR, ≥95%	An alkaline cementitious material for hydrated-lime-based putty. It can be used in experiments on high-pH conditions, formation of water resistance, alkali resistance/adaptability of HPMC, and efflorescence risk.

Table 4 Film-Forming Binders, Functional Monomers, and Setting Regulators

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Water-soluble film-forming binder	9002-89-5	P119362	Mowiol® PVA-124 polyvinyl alcohol (PVA)	Viscosity: 54–66 mPa·s	A water-soluble film-forming polymer. It can be used in studies on putty adhesion, film formation, protective colloids for redispersible polymer powder, and aqueous polymer systems.
Vinyl acetate homopolymer	9003-20-7	P304881	Poly(vinyl acetate) (PVAC)	Approx. M.W. 500,000	A vinyl acetate homopolymer. It can be used in studies on putty bonding strength, film-forming performance, and polymer-modified systems.
Ethylene-vinyl acetate copolymer	24937-78-8	P432376	Poly(ethylene-co-vinyl acetate) (PEVA)	Vinyl acetate 12 wt%; melt index 8 g/10 min at 190°C/2.16 kg	An ethylene-vinyl acetate copolymer material. It can be used to study the main polymer of redispersible polymer powder, flexibility, adhesion, and water-resistance modification.
Vinyl acetate monomer	108-05-4	V104471	Vinyl acetate	Chemically pure (CP), ≥98%	A vinyl acetate polymer monomer. It can be used to study the origin of binding polymers, film-forming resin synthesis, and redispersible polymer powder systems.
Gluconate retarder	527-07-1	G278703	Sodium D-gluconate	≥99%	A gluconate complexing regulator. It can be used in experiments on setting time, open time, and ion complexation in gypsum-based and cement-based systems.
Organic acid retarder	87-69-4	T112459	L-Tartaric acid	≥99%	An organic acid setting regulator. It can be used to study setting time, early strength, and application open time in gypsum systems.
Organic acid complexing regulator	77-92-9	C108869	Citric acid anhydrous	AR, ≥99.5% (T)	An organic acid complexing regulator. It can be used in studies on open time, pH adjustment, and setting behavior in gypsum-based and cement-based putty.
Calcium salt early-strength regulator	544-17-2	C755623	Calcium formate	UltraBio™, ≥99% (T)	A calcium salt early-strength regulator. It can be used in studies on early strength, low-temperature application, and setting/hardening behavior in cement-based putty.

Note: The above products are representative Aladdin products related to scientific research, analytical testing, and formulation studies. They are mainly intended for understanding raw material structures, mechanisms of action, performance comparisons, and experimental verification in putty systems, and are not intended as a basis for industrial production dosing. In practical applications, comprehensive evaluation should be carried out based on product quality standards, regulatory compliance, safety requirements, cost, supply stability, and application test results. Reagents involving flammability, corrosiveness, volatility, or special management requirements should be used according to the product SDS, COA, and laboratory safety practices. For more product specifications, grades, and COA information, please search by “product name/CAS/catalog number” on the Aladdin website.

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