This page contains a Flash digital edition of a book.
78 TEXTURES 1


0.1


0.01


Figure 3: Reduction of the critical micelle concentration (CMC) of sodium cocoyl glutamate (Perlastan SC 25 NKW) and sodium lauroyl sarcosinate (Perlastan L-30) by equivalent combination with coco glucoside (1:1).


rinse-off formulations showed a high degree of acceptance by the subjects in terms of their mild, nourishing, cleansing and foaming effect.


Glutamic acid as a starting material has the advantage that production is carried out by natural fermentation processes. Thus, Perlastan glutamates such as SC 25 NKW, SL and SCG 50 ZPF fulfil the requirements for obtaining certification by various organisations such as Cosmos, Ecocert, Natrue, ECO-Label and Nordic Swan. They can be readily used as the main components or secondary surfactants in formulations when certification as natural cosmetics is required.


Their mild and particularly skin-friendly character is combined with a pronounced foaming behaviour and excellent aerobic and anaerobic biodegradability.6


These


positive features make the range of N-acyl sarcosinates and N-acyl glutamates surfactants of choice to meet increasingly


75 65 55 45 35 25 10 100 Time (ms)


n Water n Sodium Cocoyl Glutamate/ (Perlastan SC 25 NKW) n Sodium Cocoyl Glutamate/Coco Glucside (1:1) n Sodium Cocoyl Glutamate/Coco Glucside (1:1)/Xanthan Gum (1%) n Coco Glucoside


Figure 4: Dynamic surface tension of sodium cocoyl glutamate (Perlastan SC 25 NKW) and in combination with coco glucoside (1:1) and xanthan gum (1%) as a function of surface age (active content of 1 g/l).


PERSONAL CARE EUROPE 1000 10000


sophisticated needs of consumers with respect to naturalness, health and performance.


In this article, the performance of amino acid-based surfactants and their formulations was examined by various methods with regard to their cleansing power, foam ability and foam structure and compared with conventional standard surfactants.


Cleansing performance To evaluate cleansing performance of surfactants, the determination of critical micelle concentration (CMC) can be measured by means of the ring tensiometer. The maximum reduction of surface tension of an aqueous surfactant solution is measured as a function of surfactant concentration. The lower the CMC value, the better the surfactant performance. Measurements with the ring tensiometer method have shown that


75 65 55 45 35 25 10 100


n Water n Sodium Lauroyl Sarcosinate (Perlastan L-30) n Sodium Lauroyl Sarcosinate/Coco Glucside (1:1) n Coco Glucoside


Figure 5: Dynamic surface tension of sodium lauroyl sarcosinate (Perlastan L-30) and its equivalent combination with coco glucoside (1:1) as a function of surface age (active content of 1 g/l).


September 2018 1000 Time (ms) 10000


standard anionic surfactants SLS and milder SLES have a CMC value of 1.2 g/l (SLS) and 0.3 g/l (SLES) respectively (Fig 2). The relatively high value for SLS


corresponds to a poor cleansing performance that can only be compensated with a higher level of use of surfactant in the formulation. For this reason, it is common practice to include additional surfactant(s) with particularly low CMC in a formulation to reduce the CMC of the formulation as a whole.


A widely used and convenient


formulation of cleansing products is the mixture of anionic surfactant SLES and amphoteric CAPB (CMC 0.12g/l). However, the strong ionic structure of the sulphate group in SLES increases the potential for creating conditions that can show as skin irritation and can lead to intolerance especially if someone has sensitive skin. In this case the use of amino acid-based


γdym


(mN/m)


CMC (g/1000ml)


SLS SLES CAPB


Perlastan L-30


Perlastan SC 25 NKW Coco


Glucoslde


Perlastan L-30 /Glucoslde 1:1


Glucoslde 1:1


Perlastan SC 25 NKW/


γdym


(mN/m)


©deniskomarov/Fotolia


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112