10 H & PC Today -HouseholdandPersonalCareToday- vol.14(5)September/October2019 SUSTAINABILITY YASH PARULEKAR MonoSol, LLC, a Kuraray Division, Merrillville, USA WATER-SOLUBLE BIODEGRADABLE MATERIALS: THE IDEAL CRADLE-TO-GRAVE Polyvinyl alcohol (PVOH) is a water-soluble polymer which eventually breaks down via biodegradation into carbon dioxide and water. PVOH is a colorless, odorless and non- toxic polymer found in all kinds of everyday products: It is used to make coatings for pharmaceuticals that dissolve on your tongue or in your stomach and it is used in contact lens solution and eye drops to keep your eyes clean and moist. PVOH is the basic component of water-soluble films used by consumers in detergent applications for over 20 years. These films are used to package highly concentrated cleaning formulations (thereby protecting the user from being exposed to the ingredients) that enable high-efficiency cleaning while reducing the environmental impact (lower transportation costs, lower cleaning temperatures, low-water cleaning cycles). The consumer uses this convenient and compact delivery format by just tossing the packet into the washing machine where the PVOH film dissolves and releases the cleaning ingredients, then is flushed down-the-drain into waste-water-treatment facilities. Micro-organisms in waste-water systems eat dissolved PVOH molecules and break them down into carbon dioxide and water (3). Thus, for the consumer, the whole process from use to disposal is convenient and does not require any change in habits (like separating recyclable material, removing specific components or needing a specific composting process). Everything happens in the normal washing process without additional steps and the PVOH disappears down-the-drain in normal use. No plastic waste and no litter remain. Consumers are not required to learn or implement new behaviors – the ideal cradle to grave story. WHAT IS THE CRADLE-STORY: WHERE DOES IT COME FROM? PVOH is made by first polymerizing vinyl acetate monomer to Poly-vinyl acetate (PVAc) which is commonly used in commercial glue. This is further hydrolyzed (replacing some of the acetate groups with hydroxy groups) to get PVOH. Yet not all PVOH is the same, nor does it have the same properties (analogous to paper where tissue-paper and cardboard are both types of paper but with very different properties). PROBLEMS WITH THE CURRENT “PLASTICS”: The ever-increasing usage of plastics in our everyday lives and the consequent disposal into the environment has led to significant amounts of this generated plastic waste accumulating as litter and impacting the quality of our lives. Single-use plastics, including plastics bags, are facing legislative bans in numerous countries as a means of addressing this problem (1). One of the solutions for this issue has been the use of biodegradable materials for single-use applications. But these materials have their own set of problems. For example, most biodegradable materials need special facilities (depending on the method of biodegradation such as industrial composting or aerobic digesters) and consequently need the consumers to be educated on how to dispose of such. If not disposed properly, these materials affect the recycling stream that is meant for conventional materials such as PP or PET or end up in landfill with the same end-of-life as a conventional material. Some municipalities have also stopped accepting biodegradable materials in composting facilities as they devalue the nutritional quality of the compost that is resold to agriculture (2). The ideal solution for all of these issues would be a material that performs its intended use and then disappears without needing extra effort or changing consumer habits. Water-soluble polyvinyl alcohol (PVOH) is the ideal material that fulfils these requirements. Biodegradable, water-soluble materials draw interest in applications for single-use plastics Materials used in single-use plastics are have their fair share of issues especially with regards to end-of-use which are leading to such plastics accumulating as waste. Polyvinyl Alcohol offers a working solution for such issues due to its ideal profile of performing in use and then disappearing via biodegradation without the need for special facilities nor changing consumer habits. PVOH’s lifeline is explained starting from the cradle (where it is differentiated based on chemical modification) to its use in applications such as convenience-enabling detergent water-soluble pouches, and finally to the end-of-life via dissolution and biodegradation. Water-soluble PVOH films are also not a source of marine micro-plastics and combined with their diverse benefits could be the answer we are all looking for in today’s plastic-waste challenged environment. ABSTRACT KEYWORDS: Microplastics, biodegradation, single-use plastics, sustainability.