Cellulose ethers play a vital role in various industries. There is a diverse range of cellulose ethers available on the market. Hydroxypropyl Methylcellulose (HPMC) and Hydroxyethyl Methylcellulose (HEMC) stand out as popular choices. They are the cellulose derivatives.

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This guide delves deep into the common properties and differences between HPMC and HEMC. We will go further about their chemical structures, properties, and optimal use cases. Let’s get started!

What is Cellulose Ethers?

Cellulose ethers are a group of derivatives formed by the reaction of cellulose. That includes the reaction of alkali with cellulose and etherifying agents. They are products where ether groups partially or completely replace hydroxyl groups on the cellulose molecule.

Cellulose ethers are used in construction projects as thickeners, binders, and emulsifiers. You can find a lot of them used in construction to enhance performance.

Cellulose≠Cellulose Ether

About Cellulose

Cellulose is a natural renewable resource primarily sourced from terrestrial plants and certain marine organisms.

About Cellulose Ethers

The raw material for producing cellulose ethers comes from two major sources: cotton and wood cellulose. In China, cellulose ethers are primarily derived from refined cotton.

Top 4 Cellulose Ethers In Construction:

– HPMC

– HEMC

– HEC

– CMC

Besides construction, you can find them in daily chemicals, paints, and more industries.

What is Hydroxypropyl Methyl Cellulose(HPMC)?

HPMC is a type of cellulose ether derived from natural cellulose. HPMC chemical is a water-based product. It can form gel-textured colloids when dissolved in water. It is a thickener, water retention agent, and film-forming agent in various applications.

Top 7 HPMC Uses:

– Tile Adhesives.

– Wall Putty.

– Mortars.

– Plasters.

– Paints.

– Honeycomb Ceramic.

– Daily Chemicals.

What is Hydroxyethyl Methyl Cellulose(HEMC)?

HEMC is also known as MHEC on the market. HEMC is a non-ionic cellulose ether. It serves as emulsion protective colloids in polymerization processes. It can undergo targeted modifications for versatile applications.

MHEC Powder Uses by Industries:

– Building and Construction.

– Waterborne Coatings.

– Personal Care Products

– Oil Technologies.

Top 7 Differences between HPMC and HEMC

1. HPMC and HEMC: Difference in Functional Groups

HPMC: Methoxy (-OCH3), Hydroxypropoxy (-OCHCH2OH) groups.

HEMC: Methoxy (-OCH3), Hydroxyethyl (-OCH2CH2OH) groups.

> Methoxy Group (-OCH3)

Lacks a hydroxyl group, exhibits low polarity, and has poor hydrophilicity.

> Hydroxyethyl Group (-OCH2CH2OH)

Contains a hydroxyl group, demonstrates higher polarity, and excellent hydrophilicity.

> Hydroxypropyl Group (-OCHCH2OH)

It contains a hydroxyl group and has good hydrophilicity. However, due to steric hindrance from the methyl group, its polarity is less than that of hydroxyethyl. This issue may lead to HPMC having a less effective thickening effect than HEMC.

2. HPMC and HEMC: Differences in Degree of Substitution (DS) Standards

The degree of substitution of hydroxyethyl and hydroxypropyl groups is relatively close.

Molecular Weight of the Functional Groups

> Hydroxyethyl: 60

> Hydroxypropyl: 74

This implies that even with the same degree of substitution (DS) in terms of mass fraction, HEMC contains a higher number of hydroxyethyl groups compared to the other. So, HEMC has a higher DS than HPMC.

3. HPMC and HEMC: Differences in the Impact of Functional Group

A higher degree of hydrophilic substitution leads to stronger binding with water molecules. Methyl cellulose ethers can dissolve in cold water. But, as the solution temperature rises, there will be an issue comes up. The detachment from cellulose molecules and forming gel-like precipitates. This is also known as gelation.

Gel Temperature

HEMC’s gel temperature is higher than HPMC. WOTAIchem’s standard HEMC gel temperature is around 75° to 85°. And the HPMC gelation temperature is around 55° to 75°.

Therefore, if you reside in countries with hot climates like India, Indonesia, or Africa, MHEC powder is the best choice! You can also choose our pure HEMC powder for construction projects in extreme environments.

If you want to learn more, please visit our website Hydroxypropyl Methyl Cellulose (HPMC).

Its application performance shows that at the same dosage and viscosity level. HEMC has a higher water retention rate at high temperatures, as illustrated in the following graph:

4. HPMC and HEMC: Differences in Water Solubility

HPMC with delayed dissolution is called surface-treated HPMC. It readily dissolves in hot water and forms clusters in cold water before swelling. In contrast, HEMC readily dissolves in cold water but does not dissolve in hot water. So, HPMC solubility is better than HEMC’s.

5. HPMC and HEMC: Difference in Price

Typically, the HEMC powder price is slightly higher than that of MHEC powder price. The main distinction lies in what you prioritize.

If you have a sufficient budget, we recommend using MHEC. However, the choice between these cellulose ethers should also be based on your specific application needs.

6. HPMC and HEMC: Different in Applications

HEMC is ideal for environments with temperatures around 45-50°C. It is suitable for summer construction. When used in equivalent amounts to HPMC, HEMC demonstrates superior water retention, heat resistance, and sag resistance. HEMC also introduces finer air bubbles compared to HPMC.

Other benefits of HEMC powder:

> Extending setting time,

> Enhancing workability.

> Better pumpability during construction.

HPMC vs. HEMC: Key Takeaways

The main difference between HEMC and HPMC is their chemical structures. It is determined by differences in the number of functional groups and their hydrophilicity. HEMC cellulose exhibits stronger water retention in construction projects in hot climates. And the HPMC cannot achieve the same effects as HEMC through modification.

What Are the Common Properties of HPMC and HEMC?

1. Solubility

The solubility of cellulose ethers in alkaline aqueous solutions, water, or organic solvents depends on the nature of the etherifying groups and the degree of substitution (DS).

DS < 0.1: Insoluble.

DS 0.2~0.5: Soluble in alkaline aqueous solutions.

2. Viscosity of Aqueous Solutions

Influencing Factors of Cellulose Ether Viscosity:

– Polymer chain (degree of polymerization or molecular weight).

– Solution concentration.

– Temperature.

3. Stability

Cellulose ethers are susceptible to cellulase enzymes and microorganisms. Stability increases with a higher degree of substitution or uniformity of substitution.

4. Toxicity and Ecological Impact

Cellulose ethers are non-toxic. They can undergo biodegradation. So, long-term storage and accumulation should be avoided.

5. Uses

HEMC and HPMC powders are two commonly used cellulose ethers in dry-mix mortars for construction applications.

Your Trusted Cellulose Ether Factory for HPMC and HEMC Supply

WOTAIchem is one of the largest cellulose ether manufacturers in China. We provide quality HPMC, HEMC, and HEC chemicals for your different construction applications.

WOTAIchem offers customized solutions for cellulose ethers. Our team comprises experts with years of experience. They can design products and formulations tailored to your specific requirements. Our sales team can also provide analysis and market trend updates on the cellulose ether market. We are committed to the long-term growth of both parties.

Contact WOTAIchem today to explore how we can enhance your construction projects!

Introduce

Hydroxypropyl methylcellulose, commonly known as HPMC, is a water-soluble polymer widely used in medicine, cosmetics, food and other industries. HPMC can be used as thickener, binder, emulsifier and stabilizer.

1. Choose the appropriate grade of HPMC

The solubility of HPMC depends on its molecular weight, degree of substitution, and particle size. Selecting the correct grade of HPMC is important to ensure its proper solubility in a specific application.

For example, low molecular weight HPMC has better solubility in water and organic solvents than high molecular weight HPMC. However, high molecular weight HPMC has better film-forming properties, which makes it suitable for tablet coating.

Likewise, HPMC with a high degree of substitution is more soluble in water than HPMC with a low degree of substitution. HPMC with a low degree of substitution is often used in sustained-release formulations because it forms a more stable and dense matrix.

The particle size of HPMC also affects its solubility. HPMC fine particles dissolve faster than coarse particles. Therefore, it is important to select the correct HPMC particle size for a specific application.

2. Use the correct solvent

The solubility of HPMC depends on the nature of the solvent. HPMC is soluble in water and some organic solvents, such as ethanol, methanol, and isopropyl alcohol. However, the solubility of HPMC in organic solvents depends on its polarity.

Water is the most commonly used solvent for HPMC because it is nontoxic, cheap, and readily available. The solubility of HPMC in water can be enhanced by adding salt or adjusting the pH.

The pharmaceutical industry commonly uses organic solvents such as ethanol, methanol, and isopropyl alcohol to dissolve HPMC in formulations such as tablets, capsules, and oral solutions. However, there may be some disadvantages to using organic solvents, such as toxicity, flammability, and environmental concerns.

3. Appropriate dispersion techniques

The method of dispersing HPMC in the solvent also affects its solubility. The most common method of dispersing HPMC is wet granulation, in which HPMC is mixed with other excipients and solvent is added to form a paste. The paste is then dried and sieved to obtain granules.

However, inappropriate wet granulation techniques may result in poor solubility and solubility of HPMC in the final product. Therefore, it is important to use appropriate wet granulation techniques (e.g., proper mixing, drying, and sieving) to obtain granules of appropriate size and density.

Another method of HPMC dispersion is the dry granulation technique, in which HPMC is mixed with other excipients and compressed into tablets. The tablets are then ground and sieved to obtain granules. When using sensitive drugs, dry granulation is preferred and solvents should not be used.

4. Storage conditions

Storage conditions of HPMC also affect its solubility. HPMC should be stored in a dry, cool and dark place to prevent moisture and sunlight exposure. Moisture causes HPMC to swell, thus affecting its solubility.

In conclusion

Selecting the appropriate HPMC grade, using the appropriate solvent, appropriate dispersion technology, and appropriate storage conditions are important factors that affect the solubility of HPMC. By considering these factors, the solubility of HPMC can be optimized to achieve the desired quality of the final product.

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Post time: Sep-13-