Diapers

Diapers are used primarily by infants, toddlers who have not yet been toilet trained, and children who wet the bed. They are also used by adults in certain circumstances or for various medical conditions, such as incontinence. Adult users can include the elderly, hospital bedridden patients, those with certain types of physical or mental disabilities, and those who work in extreme conditions such as astronauts. It is not uncommon for people to wear diapers under drysuits.

History:

The first waterproof diaper cover was invented in 1946 by Marion Donovan, a professional homemaker who wanted to make sure her children's clothes and bedding were kept dry while they slept. She also invented the first paper diapers, but executives did not invest in the idea and it was consequently scrapped for more than a decade until Procter & Gamble used Donovan's design ideas to create Pampers. Another disposable diaper design was developed by Valerie Hunter Gordon and patented in 1948. The introduction of the superabsorbent polymer material known as sodium polyacrylate in 1984 was originally developed in 1966.

Wrapping them up can potentially serve as a good bonding experience for both parents and children. Children who wear diapers may experience skin irritation, commonly known as diaper rash, from constant contact with fecal matter, as fecal matter contains urease, which catalyzes the conversion of urea in urine to ammonia, which can irritate the skin and cause painful redness. Divers wear diapers in their drysuits for long exposures. The Maximum Absorption Garment (MAG) is an adult diaper with additional absorbent material worn by NASA astronauts during take-off, landing, and extravehicular activity (EVA).

Super absorbent polymers (SAP):

Sodium polyacrylate, also known as a water lock, is a sodium salt of polyacrylic acid with the chemical formula [−CH2 - CH (CO2Na) -] n and is widely used in consumer goods. This superabsorbent polymer (SAP) has the ability to absorb 100 to 1000 times its mass in water. Sodium polyacrylate is a chemical polymer made up of chains of acrylate compounds. It contains sodium, which gives it the ability to absorb large amounts of water. Sodium polyacrylate has many favorable mechanical properties. Some of these advantages include good mechanical stability, high heat resistance, and strong hydration. It was used as an additive in foods such as bread, juices, and ice cream. 

While sodium neutralized polyacrylic acids are the most common form used in industry, other salts are also available including potassium, lithium, and ammonium. Super absorbent polymers similar to sodium polyacrylate were developed by the United States Department of Agriculture in the 1960s. The same sodium polyacrylate is found in sanitary napkins during menstruation.

Before these substances were developed, the best water-absorbent materials were cellulosic or fiber-based, such as tissue paper, sponge, cotton, or fluffy pulp. These materials can only store 20 times their own weight in water, while sodium polyacrylate can store 100 times their own weight in water. The USDA was interested in developing this technology because it wanted to find materials that could improve the protection of water in the soil. Through extensive research, they found that the gels they made did not emit water, as fiber-based materials would.

SAPs used in hygiene products are usually sodium neutralized, while SAPs used in agricultural applications are potassium neutralized. Sodium polyacrylate absorbs thirty times its own weight in urine. The cotton in the diaper also absorbs the urine. Babies up to one year old produce 2 milliliters of urine per kilogram of body weight per hour, about 15 grams of urine per hour for an average of six months. Sodium polyacrylate can absorb about 300 times its own weight in distilled water.

Diaper layers:

The top sheet (polypropene): 

The diapers themselves consist of several different layers. The top layer closest to the baby's skin is usually made of polypropylene. Some brands also have a thin layer of lotion on the top sheet to protect the baby's skin. This diaper layer allows the baby's urine to pass through the other diaper layers underneath.

Acquisition layer (cellulose and polyester): 

The layer below the cover sheet is the acquisition layer. This layer, usually made of cotton and polyester, absorbs urine and carries it away from the baby's skin. Cotton absorbs up to 27 times its own weight in water. The salts and other compounds in your urine reduce the amount you absorb compared to that number, but you still absorb it quite well. On its own, however, it won't be long before your baby's diaper starts to leak.

Absorbent Layer (Sodium Polyacrylate): 

This is where our next layer comes in. The absorbent layer under the absorbent layer also contains some cotton, but another polymer - sodium polyacrylate. This is a super absorbent polymer that is capable of absorbing a whopping 800 times its own weight in distilled water. As with cotton, the amount of urine it can hold is reduced by other compounds found in urine. Even so, it still handles an impressive 30 times its own weight. As it absorbs urine, it forms a gel that prevents moisture in the diaper. 

The average six-month household produces approximately 15 grams of urine per hour. Most diapers only contain 2-4 grams of sodium polyacrylate, which, along with absorbent cotton, is enough to absorb the urine for several hours and keep babies dry at night.

Backsheet (polypropylene, polyethylene film): 

The last layer of the single-use diaper is the waterproof back sheet. This layer is usually made of polypropylene and polyethylene and prevents moisture from the diaper from transferring to the baby's sheets or clothes. 

Moisture Indicators (Bromophenol Blue): 

In recent years, the exterior of some smaller baby diapers has received a “moisture indicator”. This usually takes the form of a color line that changes color when the inside of the diaper is wet, allowing parents to know when to change the diaper.

 

Many diapers that contain a moisture indicator appear to use a chemical called bromophenol blue. Bromophenol blue is a pH indicator, that is, it changes color based on the surrounding acidity or alkalinity. In diapers, bromophenol blue appears yellow (pH<6) when the diaper is dry. It turns blue (pH 7.6) when the diaper is wet.

Environmental impacts:

The average child needs a total of about 5,000 diaper changes. It takes an estimated 450 years for a disposable diaper to break down in a landfill. Apart from a large amount of garbage, disposable diapers contain many harmful substances. Tributyltin (TBT): a biocide used to prevent the growth of bacteria. It is toxic to marine life and humans. It damages fertility, fetuses, and our organs. TBT can be fatal if inhaled and does not break down. TBT remains in our ecosystem and enters our food chain.

 

Dioxins: a group of persistent organic pollutants. Dioxins are a by-product of bleaching diaper material. They are carcinogenic and have long-term health problems. According to the EPA, dioxins are highly toxic. Adhesives, synthetic dyes, and perfumes: They are made and contain the chemicals on this list. Adhesives are used to hold the entire diaper together. Synthetic dyes create the cute images you can find on diapers, as well as the colored straps and handy strip that tells you when to change your baby. Diapers use perfumes to hide odors. 

Sodium polyacrylate: used as an absorbent filler. Menstrual pads containing this compound have been linked to cases of toxic shock syndrome. Volatile organic compounds (VOCs) such as toluene, xylene, ethylbenzene, and dipentene are used to make dyes, polymers, and adhesives. The problem with these chemicals, however, is that when exposed to heat, they are quickly released into the air.

 

Plastics / Polymers: mainly polypropylene and polyethylene, but also polyester, polyurethane, and polyolefin. They are the main materials used in the packaging of products, household products, and the manufacture of plastic bags. Most of a diaper is made from these non-recyclable plastics. Phthalates - Although used to soften plastics, diaper adhesives, dyes, and perfumes also contain these chemicals. People of all ages can experience side effects from phthalates, but unborn babies and young children are potentially more susceptible. Petroleum / Petrolatum: used to prevent diaper leaks.

Solution:

Natural diaper brands like Eco Pea Co. can break down after just 2-3 months. They also use eco-friendly water-based ink. Since bamboo naturally inhibits odors and is antibacterial, opting for a bamboo diaper subscription is not only better for our planet, but also safer for your child. Reusable cloth diapers have come a long way since their inception. The classic image of a cotton sheet fastened with safety pins is no longer a reality. 

They have updated cloth diapers with contours, velcro or snaps, leak protection, and some very fancy prints. Now, these diapers are made from breathable fabrics and you don't need to soak them before washing (like it used to be). With all-in-one cloth diapers, all you have to do is scoop the solids out of the diaper and toss them into the washing machine. They are like new after two washes.

Reference:

1) https://en.wikipedia.org/wiki/Diaper

2) https://en.wikipedia.org/wiki/Superabsorbent_polymer

3) https://en.wikipedia.org/wiki/Sodium_polyacrylate

4) https://www.diaperanswers.org/diapers-the-environment/

5) https://www.greenmatters.com/p/are-diapers-biodegradable-compostable