Commercially Available Rheology Modifiers

Introduction   72

1. Acrylic Polymers   74

2. Cross-linked Acrylic Polymers   81

3. Alginates   89

4. Associative Thickness   94

5. Carrageenan   99

6. Microcrystalline Cellulose   106

7. Carboxymethylcellulose Sodium   109

8. Hydroxyethylcelluose   114

9. Hydroxypropylcellulose   119

10. Hydroxypropylmethylcellulose   121

11. Methylcellulose   128

12. Guar & Guar Derivatives   132

13. Locust Bean Gum   138

14. Organoclays   141

15. Polyethylene   151

16. Polyethylene Oxide   157

17. Polyvinylpyrrolidone   161

18. Silica   167

19. Water-swellable Clay   174

20. Xanthan Gum   184

Introduction

This part of the handbook presents the commercially available product lines of the 26 rheology modifier suppliers who have provided technical information for this work. Over 1000 products are included herein. It is also probable that there are other suppliers that the authors are not aware of, especially in the "Pacific Rim" or South America. Handbook users in those areas should consult local manufacturer directories to determine if other suppliers exist in their area.

The term "commercially available" is intended to indicate that the products listed are available to any customer in any quantity, from as little as 501bs. to 50 tons or more. Many suppliers also produce other grades of product that are classified as experimental or proprietary. These are grades that are specially manufactured for specific large-volume applications or customers. These grades are not included in this handbook.

Twenty different chemical types of rheology modifiers are included in this part of the handbook. They differ in chemical structure and performance. Each Section begins with a brief description of the chemical type and some key features and recommended applications for the particular type of rheology modifier. This information is obtained from the supplier's technical literature and is not intended to be an exhaustive treatise on the subject. In-depth technical information is usually available in the supplier's technical literature. Reference to this technical literature is also included in the introduction to each Section.

It does not contain information on the supplier's recommended handling procedures for his products. This is because it may vary for different suppliers and may, in fact, vary for different products from the same supplier. The supplier's technical literature is always the best source of information on the recommended handling procedure to use.

In each section the product lines are presented alphabetically by supplier's name. Each product line is arranged according to the suppliers recommended application area for the products, i.e., food, pharmaceutical, personal care or household/institutional.

The product line data are believed to be complete and accurate as of early-1999. But suppliers are continuously adding new and improved products to their lines. The handbook user is urged to contact suppliers (see Appendix C for contact information) to learn about new products that might also be candidates for the intended application.

Note:

These tables also contain the following less common abbreviations:

1 Acrylic Polymers

A Chemical Nature

Acrylic acid, H2C = CHCOOH, is an important building block of the chemical industry. The molecule contains both an unsaturated moiety that can be used for free-radical polymerization and a carboxylic acid group that can be reacted with a host of different chemical species. Although the overall chemical structure of the group of polymers in this Section varies, they all possess two common features; an acrylic polymer or copolymer backbone and pendant carboxylic acid groups, in some cases reacted with other organic species.

When dispersed in aqueous media, and while the system is acidic, they produce minimal rheological effects. But when the pendant carboxylic groups are neutralized with an alkaline ingredient, the polymer is said to "swell" producing dramatic viscosity increase and rheology modification. Thus, these products are sometimes referred to as alkali-swellable acrylic polymers. They are highly efficient thickeners and rheology modifiers.

F Useful References:

1. "Acrysol® Thickeners and Rheology Modifiers", Rohm and Haas Company Bulletin RMT2A.

2. "Aculyn® 33 personal care polymer", Rohm and Haas Company Bulletin FC-258.

3. "Hypan® Hydrogels - The link to versatile elegance", LIPO Chemicals Bulletin.

4. "STRUCTURE® Rheology modifiers for hard-to-thicken systems", National Starch & Chemical Bulletin l715-97-292.

Table 2.1a

LIPO Chemicals, Inc. Patterson, NJ, USA

Note for LIPO Acrylic Polymer data:

1 0.5% Aqueous solution measured at 25°C using Brookfield Model LVT with Helipath spindle T-E @ 12 rpm.

Table 2.1b

National Starch and Chemical Bridgewater, NJ, USA

Notes for National Starch and Chemical Data:

1 INCI Name: Acrylates/Steareth-20 Itaconate Copolymer

2 INCI Name: Acrylates/Ceteth-20 Itaconate Copolymer

3 INCI Name: Acrylates/Aminoacrylates Copolymer (Proposed)

4 pH adjusted to 9 with NH4OH, using Brookfield Model RV @ 10 rpm.

Table 2.1c

RHEOX, Inc. Hightstown, NJ, USA