HPMC vs HEMC: 7 Differences for Effective Cellulose Ethers Comparison

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.

 

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.

 

wotai-hpmc

 

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.

 

mhec-manufacturer

 

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.

hpmc-vs-hemc

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.

 

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:

 

water-retention-cellulose

 

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.

 

waterproof-mortar

 

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.

 

cellulose-ether-research

 

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.

 

mhec-cellulose-product

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.

 

hpmc-and-hemc

 

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!

 

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