Thursday, March 3, 2011

thickeners thickener classification, application and selection mechanism

 Pesticide formulations blog:
Liu Yi, Gao Ciba Specialty Chemicals (China) Company, Guangzhou company has Yang, Guangzhou 510095
Abstract: A review of the thickening agent used in cosmetics: mineral salts, surface active agent class , water-soluble polymer such as fatty acids and fatty alcohol type 200 kinds. thickener with the formation of rod-like surfactant micelles, hydration with water three-dimensional network structure formed, or the use of their long chain structure of macromolecules The purpose of the system to achieve thickening. thickener described in detail the compatibility of performance, range, impact factors and thickening mechanism of classification. in the product development process according to recipe formulation pH, stability, irritation, foam, formulation cost, if transparent, flow shape, color, electrolyte stability, and comprehensive regulatory and other requirements to consider, in order to effectively adopt an appropriate thickener. only by constantly sum up experience in practice in order to truly understand how to effectively use thickener.
Key words: cosmetics; thickening agent; water-soluble polymer; surfactant
CLC number: TQ658
Document code: A
Article ID :1001-1803 (2003) 01-0044-05
during the formulation formulators usually have to consider the flow form the final product formulation, to give the appropriate form of product flow to bring beauty, ease of use and production, the stability of the formula There is also some influence. some form of product flow even play a significant role in the use of products such as toothpaste, requires good thixotropy of products, because the time required to maintain good out of shape, the requirements of toothpaste when brushing your teeth changes in the external force can quickly spread out thin.
form of fluid flow into Newtonian fluid and non-Newtonian fluid, Newtonian fluid shear stress and shear rate is proportional to the fluid; non-Newtonian fluids have false plastic fluid, plastic fluid, and swelling fluid. pseudoplastic and plastic fluid belong to the fluid shear thinning, but the plastic fluid with a yield value. Expanding fluid is shear thickening fluid. To adjust the flow of products form, the formula division is adding thickener in the formula to achieve the purpose.
thickener simply is to improve the formulation of a product viscosity or consistency of the substances, the amount of thickener added little, but can significantly increase product viscosity or consistency . formulators in the choice of thickener are many factors to consider when: the main formula is to select the primary thickener consideration what kind of system for deciding what kind of thickener; followed by the product form, the product requires a different form of type of thickener, some requirements Newtonian fluid, and some plastic fluid requirements, according to the different needs of different thickener; thickener in the final product ratio of the cost of formula is also an important factor in choice of thickening agent, if The cost formula for producers and consumers are difficult to bear, then the value of this formula is not applied, the balance of the effect of thickening agent and their costs is very important.
other physical and chemical indicators of formula thickener is chosen to be considered, such as the stability of formulations, foam, etc., these are recipe some important indicators of concern, some thickeners thickening effect although the ideal, but the stability is poor or no foaming too much value. general the coordination of several thickener thickeners thickening than a single form of the final product has better rheological results.
1 thickener can be used as thickeners are described
a lot of material, from see a low molecular weight molecular weight thickener, but also polymer thickener; view from the functional groups of electrolytes, alcohols, amides, carboxylic acids and esters and so on. The following cosmetic ingredients according to the classification method thickener classification, Table l lists the currently used as a thickener.
1.1 low molecular weight thickener
1.1.1 inorganic salts
to do with the general thickening of the system surfactant aqueous solution is the most commonly used inorganic thickener is sodium chloride, thickening effect is obvious. surfactant micelles in aqueous solution, the presence of electrolytes to increase the number of the association of micelles, leading to spherical plastic beam into the rod-like micelles, so that movement resistance increases, so that the system viscosity increased. But when the electrolyte will affect the micellar structure of excessive, reduce the resistance movement, so that the system viscosity reduction, which is called salting. alcohols, fatty acids are polar organic compounds, there is the article to see them as non-ionic surfactants, because they are both pro-oil groups, there are hydrophilic groups. a small amount of organic matter in the presence of such surfactants surface tension, omc and other properties have significant impact, the role of size increases with longer carbon chain, in general, was line relationship between Pi. The role of the principle is the fatty alcohol, fatty acids can be inserted (to participate) surfactant micelles, promoting the formation of micelles, and because of the polar organic surfactant has a strong intermolecular interactions (hydrophobic interactions between the hydrocarbon chain increases the hydrogen bonding between the polar head), so that the two molecules alignment on the surface very closely, has dramatically changed the nature of the surfactant micelle, to the effect of thickening.
Table 1 Classification of
a thickener, non-ionic SAA
1, inorganic salts < br> sodium chloride, potassium chloride, ammonium chloride, chloride monoethanolamine, diethanolamine chloride, sodium sulfate, sodium phosphate, disodium phosphate and sodium triphosphate five
2, fatty alcohols and fatty acids
lauryl alcohol, myristic alcohol, C12-15 alcohols, C12-16 alcohol, decyl alcohol, hexanol, octanol, cetyl alcohol, stearyl alcohol, Shan Yu alcohol, lauric acid, C18-36 acid, linoleic acid, linolenic acid, myristic acid, stearic acid, Shan Yu acid
3, alkanol amide Diethanolamide
coconut, coconut oil monoethanolamide, coconut oil alone isopropanol amide, coconut oil amide , lauroyl - Asia-oleoyl Diethanolamide, lauroyl - cardamom acid diethyl amide, different stearin Diethanolamide, Asia oil Diethanolamide, Diethanolamide cardamom, nutmeg, Monoethanolamide, Diethanolamide oil, palm one ethanol amides, castor oil Monoethanolamide, Diethanolamide sesame, soybean Diethanolamide, stearin Diethanolamide, stearin Monoethanolamide, stearin Monoethanolamide stearate, stearic amide, tallow Monoethanolamide, wheat germ Diethanolamide, PEG (polyethylene glycol) -3 dodecanamide, PEG-4 oil amide, PEG-50 tallow amide
4, cetyl alcohol ether
polyoxyethylene (3) ether , iso cetyl polyoxyethylene (10) ether, lauryl polyoxyethylene (3) ether, lauryl polyoxyethylene (10) ether, Poloxamer-n (ethoxylated polyoxypropylene ether) (n = 105 , 124,185,237,238,338,407), etc. 5
PEG-80 glyceryl esters of butter ester, PEC-8PPG (polypropylene glycol) -3 two different stearate, PEG-200 hydrogenated glyceryl palmitate, PEG-n (n = 6,8,12) beeswax, PEG-4 iso Stearate, PEG-n (n = 3,4,8,150) distearate, PEG-18 glyceryl oleate / coconut oil esters, PEG-8 II oleate, PEG-200 glyceryl stearate, PEG-n (n = 28,200) butter, glyceryl esters, PEG- 7 hydrogenated castor oil, PEG-40 jojoba oil, PEG-2 laurate, PEG-120 Methyl Glucose II oleate, PEG-150 pentaerythritol stearate, PEG-55 propylene glycol oleate , PEG-160 Yamanashi three different glycans stearate, PEG-n (n = 8,75,100) stearate, PEG-150 / capric / SMDI copolymer (PEG -150 / capric Base / methyl acrylate copolymer), PEG-150 / stearin base / SMDI Copolymer, PEG-90. iso Stearate, PEG-8PPG-3 Dilauroyl ester, cetyl myristate ester, spermaceti Palm ester, C18m36 acid glycol ester, pentaerythritol monostearate, pentaerythritol Shan Yu ester, propylene glycol stearate, Shan Yu esters, cetyl esters, triglycerides three Shan Yu, the three hydroxyl glyceryl stearate such as
6, amine oxide
nutmeg amine oxide, different stearin aminopropyl amine oxide, coconut-amino propyl amine oxide, N-propyl amine oxide wheat germ, soybeans aminopropyl amine oxide, PEGm3
lauryl amine oxide, etc. Second, gender SAA
cetyl betaine, coconut oil and other amino-hydroxy sulfobetaine
three potassium ion SAA
oil, potassium stearate other
four water-soluble polymer
1, cellulose
cellulose, cellulose gum, carboxymethyl hydroxyethyl cellulose, cetyl hydroxyethyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, carboxymethyl cellulose
2, poly vinyl
PEG-n (n = 5M , 9M, 23M, 45M, 90M, 160M) and other 3, polyacrylic acid
acrylate / C10-30 alkyl acrylate cross-linked polymer, acrylate / hexadecyl ethoxy ( 20), itaconic acid ester copolymer, acrylate / hexadecyl ethoxy (20) methyl acrylate copolymer, acrylate / alkyl ethoxy fourteen (25) acrylate copolymer , acrylate / stearyl ethoxy (20), itaconic acid ester copolymer, acrylic ester ester / stearyl ethoxy (20) methyl acrylate copolymer, acrylic / eighth Alkyl ethoxy (50) acrylate copolymer, acrylate / VA crosslinked polymer, PAA (polyacrylic acid), sodium acrylate / vinyl isodecyl ester cross-linked polymer, Carbomer (polyacrylic acid ) and its sodium salt and other
4, natural rubber and modified alginate material
and (ammonium, calcium, potassium) salts, pectin, sodium hyaluronate, guar gum, cationic guar gum , hydroxypropyl guar gum, Astragalus gum, carrageenan and (calcium, sodium) salt, xanthan gum, sclerotium gum
5, inorganic polymer and its modified silicate materials
magnesium, silica, sodium magnesium silicate, hydrated silica, montmorillonite, sodium magnesium lithium silicate, water, pyroxene, stearin ammonium montmorillonite, stearic ammonia water pyroxene, quaternary ammonium -90 montmorillonite, quaternary ammonium montmorillonite -18, -18 quaternary ammonium water pyroxene
6, other
PVM / MA capric diene crosslinked polymer (polyethylene methyl ether / acrylic acid Methyl decanoate diene crosslinked polymer), PVP (PVP), etc. 1.1.4 Surfactant alkanolamide is the most commonly used class of
coconut Diethanolamide. alkanolamide compatible with the electrolyte and thickening together to achieve the best results. alkanolamide
thickening mechanism is interaction between anionic surfactant micelles, the formation of non-Newtonian fluids. a variety of different alkyl amide alcohol are very different in performance, but alone and complex the effects of which are also different, with different articles reported alkanolamide thickening and foaming. alkanolamide made recently reported that cosmetics are carcinogenic when nitrosamine potential hazards. alkanolamide free of impurities in amine, which is a potential source of nitrosamines. Currently personal care products in the cosmetics industry on whether to disable alkanolamide no official comments.
1.1 .4.2 ethers
In a polyoxyethylene ether sulfate (AES)-based active material of the formula, in general, only salt that is able to tune into the appropriate viscosity. Research indicates that this is not contained in the AES Sulfated fatty alcohol ethoxylates, for thickening surfactant solutions made a significant contribution. in-depth study found that: the average degree of ethoxylation of about 3EO or 10EO role from the time the best. In addition alcohol B thickening effect of oxygen compounds contained in its products of unreacted alcohol and the distribution of homologues has a lot width. homologues wide distribution of thickening effect when the product is poor, the more narrow homologue distribution may be have greater thickening effect.
esters is the most common thickening agent used esters. recently reported that foreign and PEG-8PPG-3-bis-iso Stearate, PEG-90 two different stearate and PEG-8PPG-3 Dilauroyl esters. these are non-ionic thickeners thickener, mainly for aqueous surfactant systems. Such thickening is not easy to hydrolyze, in a wide The pH and temperature viscosity stability. The most commonly used PEG-150 distearate. used as a thickener in the esters, the molecular weight are generally larger, so has the number of polymer performance. thickening mechanism is due to hydration in the aqueous phase to form three-dimensional network, which will be included into the surfactant micelles caused. In addition to these compounds as a thickener in cosmetics, but also can be used as emollients and moisturizers . amine oxide
amine oxide is a kind of polar non-ionic surface active agent, characterized by: in aqueous solution, due to the different solution pH values, it shows a non-ionic , can also display the strong ion nature. In neutral or alkaline conditions, ie, pH greater than or equal to 7, the oxidation of amines in aqueous solution to hydrate exists not ionized, indicating non-ionic. In acidic solution, it shows weak cationic, when the solution pH is less than 3, the cationic amine oxide is particularly evident, so it can be in different conditions with cationic, anionic, nonionic and zwitterionic surfactants such as compatibility and display good collaborative effect. thickener amine oxide is effective when the pH is 6.4-7.5, the alkyl dimethyl amine oxide can make the viscosity of the mixture of 13.5Pa.s-18Pa.s, while the alkyl amide propyl dimethyl base oxide viscosity of the mixture of amines can reach 34Pa.s-49Pa.s, which will not reduce the viscosity by adding salt. betaine and a few other
soap can also be used as thickener (see Table 1), the thickening mechanism and the role of other similar small molecules are interacting with the surfactant micelles to achieve thickening effect. soap can be used for thickening cosmetic bar, mainly for betaine surfactant water system.
1.2 Many water-soluble polymer thickener
thickening polymer thickener system is not the solution pH, or electrolyte concentration. In addition, the polymer thickener The amount to be less able to achieve the required viscosity, such as the need for a product such as coconut oil surfactant thickener Diethanolamide the mass fraction of 3.0%, to achieve the same effect can be only 0.5% of cellulose polymers . most of the water-soluble polymers in the cosmetic industry will not only grain used as thickeners, and used as a suspending agent, dispersing agent and setting agent.
cellulose in cellulose water-based systems are a class of very effective thickening agent, is widely used in various fields of cosmetics. Cellulose is a natural organic matter, it contains duplicate glucoside units, each unit consisting of 3 glucoside hydroxyl, these hydroxyl can form a variety of derivatives. cellulose thickener expansion through hydration and thickening of long-chain cellulose thickening of the system showed an obvious fake plastic flow patterns. generally use about 1% wt .
polyacrylic acid polyacrylic acid thickening agent since 1953 Coodrich will Carbomer934 to market has been 40 years, and now this series has been more thickener choice (see Table 1). polyacrylic acid thickener thickening mechanism of 2 species, namely hydrogen bonding and thickening and thickening. in and thickening is polyacrylic acid thickener in and, to the molecular ion of the main chain along the polymer a negative charge repulsion between the same sex charges prompted the formation of the molecular network structure with open straight to the thickening effect; hydrogen bonding polypropylene thickening acid thickener to form the first hydration water molecules and then with the mass fraction of 10% m20% of the hydroxyl donor (such as ethoxylated with 5 or more non-ionic surface active agent) combined to make it curly molecules solve the water system in the formation of network structure to achieve thickening effect. different pH, soluble salts of different neutralizers, and the presence of the viscosity of the thickening system have a greater impact, pH value of less than 5, pH value increases viscosity increases; pH value of the viscosity is almost constant in the 5-10; but with the pH value continues to rise, thickening efficiency also decreased. monovalent ions only reduce the efficiency of the thickening system, divalent or trivalent ion thinning will not only help system, and when the content will generate enough insoluble precipitate.
1.2.3 Modification of natural rubber and natural rubber are property
collagen protein and polysaccharides together, but as growth thickening agent for natural rubber is mainly poly polysaccharides (see Table 1). thickening mechanism is through the accumulation of sugar units in polysaccharides containing three hydroxyl groups and the hydration water molecules interact to form three-dimensional network structure, so as to achieve the effect of thickening. They Most of the flow forms an aqueous solution of non-Newtonian fluid, but some close to the rheological properties of dilute solution of Newtonian fluid. They thickening effect of general and system pH, temperature, concentration and other more related to the presence of solute, This is a class of very effective thickener, generally the amount of 0.1% -1.0%.
1.2.4 modified inorganic polymer and inorganic polymer materials
class thickener generally has three layers m-like structure or expansion of lattice structure, the most commercial uses two types of clay and water is pyroxene. The thickening mechanism of inorganic polymer dispersed in the water, one of the metal ions spread out from the chip, with the hydration progresses, it occurs swelling, and finally complete separation of lamellae, which results in the formation of lamellae and the anion layer structure of transparent metal ion colloid suspension. In this case, lamellae with the surface negative charge, it the corner and as a result of the fracture surface with a small amount of the lattice of positive charge. in dilute solution, the surface negative charge than positive charge big corner, mutual exclusion between particles, it is no thickening effect. With the addition of electrolytes and the concentration, the ion concentration, lamellar surface charge reduction. At this time, the main interaction between the repulsive force by the lamellae lamellae into the surface negative charge and positive charge of the corner between the attractiveness of parallel lamellae perpendicular to cross-linked together to form the so-called flocculated structure lead to lower consistency. such thickener is mainly used for toothpaste, shampoo, hair conditioner, cream, lotion and deodorant thickening agent. consistency generally increases with the concentration tends to increase rapidly following gently form the thixotropic flow. In addition to a thickening performance, there is stability in the system emulsion, suspension effect. its modification are the main quaternary ammonium salt of (see Table 1), modified with a lipophilic, oil content can be used for more than a system.
general class of polyoxyethylene to more than 25 000 molecular weight polyoxyethylene products known, and less than 25 000 known as polyethylene glycol . polyoxyethylene aqueous solution when the mass fraction of per cent for the pseudoplastic fluid, the solution was viscous tendencies. If the object will be immersed in one of the pull from the solution to form a long drawing and film. the greater the molecular weight and the wider the molecular weight distribution of the greater viscosity of low molecular weight and narrow molecular weight distribution of PEO is less viscous, the viscosity of the solution depends on the size of molecular weight, concentration, temperature, and viscosity measurements when shear rate. the solution viscosity with increasing molecular weight and increased with concentration, with the temperature increase (10 ℃ ~ 90 ℃) and more dramatically. polyoxyethylene pseudoplastic aqueous solution with molecular weight the decrease of lower molecular weight aqueous solution of lXl05 close to Newtonian fluid rheology. thickening effect from the dissolution of polymer chains into the surfactant system, the thickening mechanism is mainly related with the polymer chains are not dependent on the surfactant system. polyoxyethylene aqueous solution in the UV, acid and transition metal ions (especially Fe3 +, Cr3 + and Ni2 +) are automatically under the action of oxidative degradation, loss of its viscosity.
1.2.6 Other
PVM / MA capric diene crosslinked polymer (polyethylene methyl ether / methacrylate and decyl diene crosslinked polymer) is a new family of thickeners, in the past 3 years in personal care products for industrial applications It was quickly recognized. They make emulsion stability, thickening, giving excellent skin feel, almost sticky feel. can shape made into transparent gel, hair spray and latex can be used for thickening alcohol solution, glycerol and other non-water system, emulsifier in the case of suspension without the active component in toothpaste it can play a Yujie pure synergy.
PVP (PVP) is a solution only in water, soluble in most organic solvents and polyamide, the appearance of white or light yellow powder, or as a transparent liquid, water-soluble, safe and non-toxic, green chemicals. PVP is widely used in medicine, cosmetics crystal, cleaning products , beverages, textiles, paper, chemicals and printing industries. PVP thickening properties are closely related to their molecular weight, concentration in a given condition, the greater the molecular weight, the greater its viscosity. pH value and temperature effect on the viscosity of PVP solution is not obvious, crosslinked PVP no special thixotropic solution, unless very high concentrations only be thixotropic, and displays a very short relaxation time.
2 How to choose thickening agent?
thickener the reported number, the face of these thickeners in a specific product formulation development to go that route how to choose? formula system must first understand their needs and requirements, from the formulation pH, stability sex, irritation, foam, cost, whether the transparent flow shape, color, electrolyte stability and regulatory requirements and other considerations. such as shampoo, formula, pH value is generally 5.5 to 7.5, rich foam, Newtonian flow morphology , good stability, in line with regulatory requirements, the needs of the remaining are optional. ordinary shampoo wider choice of surface, but consider the cost factor is selected inorganic salts, surfactants more. conditioning shampoo, select the range narrower, generally consider the use of water-soluble polymer thickener type, particularly the use of silicone oil as a conditioner shampoo, requiring good suspension formulation system, using water-soluble polymer thickener to make formula class system is more stable . thickener compatibility between the phenomenon and do not, it should be given special attention, such as Carbomer series is very sensitive to electrolyte thickener, the thickener can add salt. Some thickener down bubble phenomenon is very obvious, such as PEGm150 distearate, PEGm120 two oleic acid methyl glucose also has a slight drop bubble phenomenon. How to choose the specific thickener in the formulation, more usually have to rely on the accumulation of thickener performance, more experimental, touch clear thickening agent used in the performance and compatibility between systems and the impact of various aspects of the formula.
3 Summary
cosmetic appearance of the shape is of great concern to consumers, the choice of a suitable thickening agent to achieve the performance required by the formula is very important, and it is an art. present a wide range of thickener, and is still emerging, it is only through various means such as suppliers, technical magazines, technical books and the Internet and other ways to understand a variety of thickening agent performance, through their own personal experiments summarized in order to truly understand how to effectively use thickener. 

1 comment:

  1. Thank you for sharing this information.
    It will really helpful to solve my confusion

    Process $ Chemical Engineering