METHOCEL™ HPMC Thickens Acid & Alkaline Cleaners

Thickening Household Cleaners and Detergents

Now more than ever, cleaning surfaces and articles has become a focus in many households and shared spaces. Many solvent- and water-based cleaning solutions used to clean highly trafficked surfaces and contaminated articles are strongly acidic or alkaline and sometimes contain organic solvents. This presents a unique challenge for formulators, who must produce cleaning solutions with stable viscosities at extreme pH and in various organic solvents.

Xanthan Gum Thickeners

Xanthan gums are often used as thickening agents in water-based cleaners due to their inexpensive nature and stability in a wide pH range. However, they do not offer good compatibility and performance in cleaners and detergent formulations that contain organic solvents. In addition, the anionic nature of xanthan gum makes it incompatible in cationic formulations.

METHOCEL™ hydroxypropyl methylcellulose (HPMC) polymers are nonionic, bio-based polymers that serve as excellent thickeners for water-based and solvent-based cleaners and detergents. 

Better Solubility and Stability

Much like xanthan gum, METHOCEL™ HPMC polymers are resilient in highly acidic and alkaline systems and produce consistent, stable viscosity from pH 3 to 11. Unlike xanthan gum, however, they are compatible with cationic materials and a variety of solvents commonly used in cleaner and detergent formulations. Some of the typical organic solvents used with METHOCEL™ are listed below.


•    Ethanol
•    Methanol
•    Acetic Acid
•    Furfuryl Alcohol
•    Propylene Carbonate

Increased Contact Time

Solutions using METHOCEL™ thickeners are pseudoplastic and gain shear-thinning rheology. This allows cleaners to be easily sprayed onto surfaces and cling to them better. Once applied to the surface, the solution's viscosity will build up, holding the cleaner in place more effectively under the force of gravity. This is useful for cleaning solutions that need to be applied onto angled or overhead surfaces and helps increase the dwell time of the cleaner to the applied area.

Enhanced Cleaning Capabilities

In addition to providing thickening and pseudoplasticity to solvent-based and water-based cleaning products in a wide pH range, METHOCEL™ will also add soil antiredeposition properties on surfaces. METHOCEL™ accomplishes this due to the surface-active action of HPMC polymers that makes them adsorb onto suspended particles. Once adsorbed, these particles are more likely to be rinsed away rather than redeposited on the surface or article. The surface-active properties of METHOCEL™ also allow it to function as a surfactant to help stabilize emulsions and different phases that may be present within cleaners and detergents. It also helps increase detergent foam height and stability.

Below are grade recommendations for METHOCEL™ in cleaning and detergent applications.

Grade Recommendations

How to Use METHOCEL™

METHOCEL™ polymers are very hygroscopic and must be completely dispersed in solution prior to hydration and thickening to avoid forming lumps. Proper dispersion can be carried out in a few different ways. These methods are covered in the sections below or can be seen in this video.

Dispersion in Hot Water

This method, also called the hot/cold technique, takes advantage of the fact that METHOCEL™ thickeners are insoluble in hot water and highly soluble in cool water. METHOCEL™ is first dispersed by mixing with one-third of the total required volume of water heated to 90°C. Once all the METHOCEL™ particles are wetted and dispersed, the remaining volume of cold water or ice is added. Once the dispersion temperature reaches the point where METHOCEL™ is soluble, the particles hydrate and viscosity increases.

Dry Blending

Dry METHOCEL™ powders can be mixed with other dry ingredients prior to adding them to the water component. Dry blending ensures METHOCEL™ particles are separated and can be completely wetted out and hydrated when water is added. The recommended ratio of dry ingredients to METHOCEL™ powder varies from 3:1 to 7:1.

Dispersion in Nonaqueous Solvents

Most METHOCEL™ grades have limited direct solubility in nonaqueous solvents. In formulations that utilize water-miscible organic solvents, METHOCEL™ powder can be dispersed in the organic solvent prior to adding water. At least 5 to 8 parts of solvent should be used for every 1 part of METHOCEL™ when preparing dispersions. The addition of water will then trigger hydration and thickening.

Conclusion

Thickening agents and rheology modifiers are particularly useful in many household, industrial, and institutional cleaning and detergent formulations. They provide the necessary viscosity control for sufficient coverage on many surfaces, including angled or overhead surfaces.

Many of these formulations use traditional thickening agents like xanthan gum, limiting the versatility of cleaners that can be made. METHOCEL™ polymers are naturally derived thickeners that have great stability in extreme pH and organic solvents, which are common in many cleaners used today. METHOCEL™ also provides value beyond thickening by adding soil antiredeposition and solution and emulsion stabilization in cleaners and detergents. 

Click below to request a sample to try in your cleaner or detergent formulation.