What is the Difference Between HPMC and MHEC

The key difference between HPMC and MHEC is that the gel temperature of HPMC is around 60 – 75 ℃ depending on the group content and different production techniques, whereas the gel temperature of MHEC is usually higher than 80 ℃.

The term HPMC stands for hydroxypropyl methyl cellulose, while the term MHEC stands for methyl hydroxyethyl cellulose. These two are important as construction chemicals and can be used as thickeners, water retention agents, and air-entraining agents. Mainly, these are used in cement and gypsum-based dry mix mortar to increase bond strength, workability, and water retention.

CONTENTS

1. Overview and Key Difference
2. What is HPMC 
3. What is MHEC
4. HPMC vs MHEC in Tabular Form
5. Summary – HPMC vs MHEC

What is HPMC (Hydroxypropyl Methyl Cellulose)?

The term HPMC stands for hydroxypropyl methyl-cellulose. It is also called hypromellose. It is a semisynthetic, inert, viscoelastic polymer useful in eye drops, as an excipient and controlled-delivery component in oral medicaments, and can be found in many commercial products.

The chemical formula of HPMC is variable because the number of monomer units that are linked together to make the cellulose polymer structure can vary. Therefore, the molar mass of this compound is also variable. Further, HPMC is a food additive and can be used as an emulsifier, thickening, and suspending agent, as an alternative to animal gelatin, etc. The E number of this compound is E464.

This is a solid substance that appears as a slightly off-white to beige powder that can be formed into granules. Moreover, this compound can form colloids when dissolved in water. HPMC is a nontoxic ingredient that is combustible and can react vigorously with oxidizing agents.

When HPMC is in an aqueous solution, it exhibits thermal gelation properties. When the solution is heated to a critical temperature, it congeals into a non-flowable and semi-flexible mass. This congealing temperature is inversely related to both the concentration of the HPMC solution and the methoxy group concentration within the HPMC molecule. In other words, the higher the concentration of the methoxy group, the lower the critical temperature.

What is MHEC (Methyl Hydroxyethyl Cellulose)?

The term MHEC stands for methyl hydroxyethyl cellulose. It is a gelling and thickening agent that is derived from cellulose. The chemical formula of this compound is variable because the number of unit structures per MHEC molecule can vary. Therefore, the molar mass also varies accordingly.

This compound is considered to be non-toxic. Therefore, it is used as a food additive. However, excessive amounts or overuse can cause irritating and harmful effects. This compound can be described as a modified cellulose polymer consisting of methyl, ethyl, and hydroxyethyl side chains.

There are some common side effects of MHEC: abdominal or stomach pain, light vaginal bleeding after the procedure, pelvic pain, slow heartbeat, etc.

This compound can be used to help improve the texture and feel of skincare and cosmetic products, but it does not provide any other benefits to the skin by means of improving the condition or the appearance of the skin.

What is the Difference Between HPMC and MHEC?

HPMC and MHEC are modified cellulose forms that are mainly used as gelling agents for thickening properties in different items. The key difference between HPMC and MHEC is that the gel temperature of HPMC is around 60 – 75 ℃ depending on the group content and different production techniques, whereas the gel temperature of MHEC is usually higher than 80 ℃.

The below infographic presents the differences between HPMC and MHEC in tabular form for side-by-side comparison.

Summary – HPMC vs MHEC

HPMC and MHEC are two types of cellulose derivatives that can be described as modified cellulose forms. HPMC stands for hydroxypropyl methyl-cellulose, while MHEC stands for methyl hydroxyethyl cellulose. The key difference between HPMC and MHEC is that the gel temperature of HPMC is around 60 – 75 ℃ depending on the group content and different production techniques, whereas the gel temperature of MHEC is usually higher than 80 ℃.

Reference:

1. “Hydroxypropyl Methylcellulose.” An Overview – Science Direct.

Image Courtesy:

1. “Hypromellose” By Edgar181 – Own work (Public Domain) via Commons Wikimedia
2. “Hydroxyethyl methyl cellulose” By chemBlink – (Attribution) via Commons Wikimedia