All-day hair manageability for textured hair types A revision of the current anti-frizz technologies and suggestions for the future Master’s thesis in Materials Chemistry MATILDE BENGTSSON Department of Chemistry and Chemical Engineering Division of Applied Surface Chemistry CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2016 MASTER’S THESIS All-day hair manageability for textured hair types A revision of the current anti-frizz technologies and suggestions for the future MATILDE BENGTSSON SUPERVISOR: Sylvain Lataste, AkzoNobel Surface Chemistry AB EXAMINER: Assoc. Prof. Martin Andersson, Chalmers University of Technology Department of Chemistry and Chemical Engineering Division of Applied Surface Chemistry CHALMERS UNIVERSITY OF TECHNOLOGY Gothenburg, Sweden 2016 All-day hair manageability for textured hair types A revision of the current anti-frizz technologies and suggestions for the future MATILDE BENGTSSON © MATILDE BENGTSSON, 2016 Department of Chemistry and Chemical Engineering Division of Applied Surface Chemistry Chalmers University of Technology SE-412 96 Göteborg Sweden Telephone: + 46 (0)31-772 1000 Printed by the Department of Chemistry and Chemical Engineering, Chalmers University of Technology. Gothenburg, Sweden, 2016 Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less. -Marie Curie All-day hair manageability for textured hair types A revision of the current anti-frizz technologies and suggestions for the future MATILDE BENGTSSON Department of Chemistry and Chemical Engineering Division of Applied Surface Chemistry Chalmers University of Technology Abstract Today consumers have expectations on hair care products that stretch far beyond merely cleaning the hair. There is a significant manageability concern regarding frizziness, especially for curly hair people when exposed to high temperature and very humid environments. The currently most widely used anti-frizz technology provides a short-term solution. Thereby there remains a significant unserved market. It was hypothesized that there are other conditioning agents on the market that have a more significant impact on frizz reduction. The aim of this study was to identify current anti-frizz ingredients and examine their performance and limitations. A market investigation was performed and it was concluded that a number of surfactants, protein derivatives and silicones would be interesting to assess. Several representatives were selected within each group in order to gain an understanding of the correlation between molecular structure and manageability performance. The active ingredients were formulated in standardized formulas for rinse-off conditioners before the performance study began. Further a method development was done regarding the objective evaluation of frizziness. Frizz is caused by an imbalance in the moisture level of hair. This study conclude that the level up and test condition regarding time, temperature and relative humidity seem to be critical for the tendency of hair to frizz. Further studies would be needed to optimize the parameters. Finally a study of the manageability performance of the formulated conditioners was performed on human hair tresses. The widely used cationic surfactant docosyltrimethyl- ammonium chloride was overall well performing, especially when it came to reduction of friction force and reduction of flyaway hair during combing. It was superior to the other cationic surfactant tested regarding reduction of frizz. This study suggests that the silicones and protein derivatives showed less promising results regarding the overall manageability. Preliminary data has implications that the efficiency of anti-frizz is correlated with cationic charge and high hydrophobicity of the conditioning agent. Key words: Surface chemistry, polymer technology, surfactant, emulsion, conditioner, personal care, hair care, anti-frizz, anti-static, combing force reduction. I Contents ABSTRACT I CONTENTS II PREFACE V 1 INTRODUCTION 2 1.1 Objective 2 1.2 Scope 3 1.3 Methodology 3 2 THEORY 4 2.1 Human hair biology 4 2.1.1 Morphologically distinct structures of hair 4 2.1.2 Molecular basis of hair fibers 6 2.1.3 Origin of hair and its impact on texture 7 2.1.4 History of hair affect the hair quality 8 2.1.5 Surface chemistry of chemically bleached hair 8 2.2 The chemistry of conditioners 9 2.2.1 Chemistry of an emulsion 9 2.2.2 Molecular basis of conditioners 11 2.2.3 Interaction of conditioning agents with hair 11 2.2.4 The function of conditioners 12 2.3 Performance study of conditioners 12 2.3.1 Emulsification during formulation 12 2.3.2 Stability testing of a formulation 13 2.3.3 Moisture content of hair 13 2.3.4 Underlying causes of frizziness 14 2.3.5 Static build-up on hair during dry combing 14 2.3.6 Friction forces on hair during wet combing 15 3 RESULTS FROM THE MARKET INVESTIGATION 16 3.1 Interviews with curly haired hair care consumers 16 3.2 Interviews with hair stylists 16 3.3 Mapped conditioning technologies 17 3.4 Summary of the conditioning technologies currently on the market 19 3.5 Interview with hair distributor regarding hair quality 20 II 4 EXPERIMENTAL PROCEDURE 21 4.1 Formulation of simple hair conditioners 21 4.2 Damaging hair by bleaching 22 4.3 Anti-frizz analysis 22 4.4 Anti-static analysis 23 4.5 Wet combing analysis 23 5 EXPERIMENTAL RESULTS AND DISCUSSION 25 5.1 Stability testing of a formula 25 5.2 Method development for anti-frizz analysis 25 5.3 Anti-frizz performance 29 5.4 Anti-static performance 30 5.5 Wet combing performance 31 5.6 Summary of the overall performance 31 6 CONCLUSIONS 33 7 RECOMMENDATIONS FOR FUTURE RESEARCH 34 8 REFERENCES 35 III IV Preface This master’s thesis was conducted during five months in the spring of 2016 within the master program Materials Chemistry at Chalmers University of Technology. The thesis was performed within the Personal Care group at AkzoNobel Surface Chemistry AB. I would like to express my gratitude towards the Personal Care group for this fruitful working experience. It has provided me with valuable insights for my future career. Further I would like to take the opportunity to thank all interviewees in this study for taking time to share your experiences and market understanding. Working with this master’s thesis has been an interesting experience, expanding my knowledge in polymer technology and surface chemistry related to new applications and exploring the dynamics of one of the strong players within the chemical industry. This version of the report covers method development and anti-frizz raw materials already in the public domain. All data on novel experimental materials, which represents a significant part of the work completed, remains confidential. Gothenburg June 2016 Matilde Bengtsson V 1 1 Introduction The use of personal care products is currently expanding both regarding sales volume and geographically. In hair care the major product is shampoo, with conditioner close thereafter1. Other important market segments are hair treatments, hair colorants and hair styling. China, with its large population, is the biggest shampoo and conditioner market, with sales at US$5.7 billion in 2013, closely followed by the US at US$5.2 billion2. Today consumers have expectations on hair care products that stretch far beyond merely cleaning the hair1. Improving the appearance of hair with shampoo and conditioners has resulted in top claims globally such as brightening/illuminating, moisturising/hydrating and restoration of damaged hair. There is also a strong market trend towards natural ingredients such as botanical/herbal2. This study will address the long term unmet consumer need and holy grail of the cosmetics industry regarding anti-frizz technologies. The most widely used technology today are silicones and deep conditioning agents such as docosyltrimethylammonium chloride, which provides an 2-4 hour solution. It is an unsatisfactory time range for frizz to be tamed only for a few hours. Therefor there remains a significant unserved market. It is crucial for the technology to function over a prolonged time in all weather conditions, while still leaving the hair looking and feeling natural to enable a wide consumer acceptance. It is especially problematic for people with curly hair that are exposed to high temperature and very humid environments. The hair type and texture affect the hair characteristics regarding appearance, manageability and response to treatment3. It is hypothesized that there are other conditioning agents on the market that have a more significant impact on frizz reduction. The long-term aim would be towards a 24 h solution, which would serve as an all-day hair manageability technology. Manageability is defined as the ease of arranging hair in place and its temporary tendency to retain in place during grooming. Manageability can be strongly related to ease of combing and flyaway hair. For curly hair individuals also frizz is part of the manageability concern, which is strongly related to the balance of moisture in the hair. Frizz has been described as a lack of alignment of the curvature of neighboring hairs of an assembly, which cause the appearance of disorder. Further it is important to distinguish the consumer perception of moisturization, which is merely related to smoothness from the scientific meaning of water content4. 1.1 Objective The purpose of the project is to define the ideal all-day anti-frizz technology for curly hair from both a consumer experience and raw material viewpoint. The aim is to gain an understanding of the performance and limitations of current anti-frizz raw materials. The project will investigate which types of molecules that are optimal and suggest possible modifications and combinations to improve efficiency. In collaboration with AkzoNobel scientists recommendations will be made to aid the intelligent design of a series of mass-market solutions for the future. The final step of the study would involve the transformation of the findings into an actionable format with any IP opportunities defined.