Performance of Green Surfactants in Heavy Duty Laundry Detergent Formulations
Liquid detergents are in increasing demand in North America, Western Europe, and Southeast Asia due to their ease of use, cleanliness, and efficiency. α-Methyl ester sulfonate (α-MES), an anionic surfactant derived from palm oil methyl ester, has been reported to have a lower manufacturing cost, good detergency at lower dosages, excellent biodegradability, higher hard water resistance, and lower eco-toxicity when compared to straight-chain alkyl benzene sulfonate (LABS). LABS were regarded as the mainstay of the detergent industry in the 20th century. Although palm-based α-MES has been successfully used as a surfactant in powder detergents, there are still some unresolved technical issues related to phase stability and viscosity when using this anionic surfactant in heavy-duty laundry detergent formulations. This paper will not only review the market overview of detergents, the application and performance of green surfactants in laundry detergents, but will also focus on the technical issues related to the use of palm-based α-MES in laundry detergents and some possible ways to overcome the formulation difficulties.
Laundry detergents used to clean fabrics are available in a number of different forms including powders, liquids, strips, tablets and bags to meet consumer preferences. Powder detergents are favored in Asian countries such as China, India and Japan due to their low cost per wash and high volume to weight ratio. Liquid detergents are popular in North America and Western Europe because they effectively pre-treat and remove stains, can be used immediately, have no solubility issues and do not require pre-washing, thus saving time and labor . Indians preferred strip
detergents before switching to powder detergents as they believe that rubbing action is important for effective cleaning of fabrics. On the other hand, detergents in the form of tablets and sachets are highly preferred in the UK and the EU because it is easy to use and there is no need to measure the amount required for each wash load.
Heavy-duty laundry detergents are usually available in powder and liquid form and are capable of removing heavy deposits from textiles through the washing process. Heavy-duty laundry detergents are usually more concentrated than light-duty laundry detergents and are therefore commonly used in washing machines. Tables 1 and 2 show typical formulations of unblended and blended heavy-duty laundry detergents (HDLD).
The global market demand for laundry detergents has reached USD 133.3 billion in 2016 and is expected to grow at a compound annual growth rate (CAGR) of approximately 4.9% from 2017 to 2025, with total revenues projected to be more than USD 205.2 billion in 2025.2025 . Among all products, laundry detergents had the largest market share, accounting for more than 31% of total revenue in 2016. Among all applications, household applications accounted for the largest share, with demand expected to exceed USD 118 billion by 2025, growing at a CAGR of 4.9% . Figure 1 shows the global laundry detergent market share by region in 2016. It can be seen that the Asia-Pacific market held the largest share, followed by Europe and North America.
Powdered detergents are expected to dominate the market from 2018 to 2025 and are expected to witness strong growth and steady penetration in developing countries such as China, India, and Brazil, where consumers prefer economical products . There is also a large portion of population in rural areas who prefer laundry detergent over other products.
