Chemical Plastic

January 4, 2013

Plastic Electronics is just in the Ascendant

Filed under: Chemical Plastic Research — Tags: , , , — Administrator @ 8:52 am

In electronics there’s a common understanding that silicon and other elements are responsible for bringing our gadgets to life while plastic serves as the supporting structure. But what if that plastic could be both the brains and the brawn? Better yet, what if plastic was pliable enough to form all sorts of wearable electronics and even implantable medical devices?

Actually, electronics made from conductive plastic have been in the works for at least a decade. Among them, one of the difficulties has been overcoming is a loss of conductivity when plastic electronics are stretched too far.

A team of researchers from the U.S., South Korea and China say that they have found a method to keep an electrical connection even after stretching their specially made plastic more than four times its normal size. The key is to make a highly porous polymer, and then fill those pores with liquid metal.

Imagine that, these “3-D stretchable conductors” being used to make artificial eyes that restore vision or synthetic skin that monitors blood glucose levels. A bit out-there, I know, but science has a knack for catching up with science fiction.

* Originally posted: Plastic Electronics is in the Ascendant

January 16, 2012

The Truth About Plastic

Filed under: Chemical Plastic Research — Tags: , , , , — Administrator @ 7:05 am

Our food and water come wrapped in plastic. It’s used in our phones and our computers, the cars we drive and the planes we ride in. But the infinitely adaptable substance has its dark side. Environmentalists fret about the petroleum needed to make it. Parents worry about the possibility of toxic chemicals making their way from household plastic into children’s bloodstreams.

 

If you know where to find a good plastic-free shampoo, can you tell Jeanne Haegele? Last September, the 28-year-old Chicago resident resolved to cut plastics out of her life. The marketing coordinator was concerned about what the chemicals leaching out of some common types of plastic might be doing to her body. She was also worried about the damage all the plastic refuse was doing to the environment. So she hopped on her bike and rode to the nearest grocery store to see what she could find that didn’t include plastic. “I went in and barely bought anything,” Haegele says. She did purchase some canned food and a carton of milk–only to discover later that both containers were lined with plastic resin. “Plastic,” she says, “just seemed like it was in everything.”

She’s right. Back when Dustin Hoffman received the most famous one-word piece of career advice in cinema history, plastic was well on its way to becoming a staple of American life. The U.S. produced 28 million tons of plastic waste in 2005–27 million tons of which ended up in landfills. Our food and water come wrapped in plastic. It’s used in our phones and our computers, the cars we drive and the planes we ride in. But the infinitely adaptable substance has its dark side. Environmentalists fret about the petroleum needed to make it. Parents worry about the possibility of toxic chemicals making their way from household plastic into children’s bloodstreams. Which means Haegele isn’t the only person trying to cut plastic out of her life–she isn’t even the only one blogging about this kind of endeavor. But those who’ve tried know it’s far from easy to go plastic-free. “These things are so ubiquitous that it is practically impossible to avoid coming into contact with them,” says Frederick vom Saal, a biologist at the University of Missouri.

Vom Saal is a prominent member of a group of researchers who have raised worrisome questions in recent years about the safety of some common types of plastics. We think of plastic as essentially inert; after all, it takes hundreds of years for a plastic bottle to degrade in a landfill. But as plastic ages or is exposed to heat or stress, it can release trace amounts of some of its ingredients. Of particular concern these days are bisphenol-a (BPA), used to strengthen some plastics, and phthalates, used to soften others. Each ingredient is a part of hundreds of household items; BPA is in everything from baby bottles to can linings (to protect against E. coli and botulism), while phthalates are found in children’s toys as well as vinyl shower curtains. And those chemicals can get inside us through the food, water and bits of dust we consume or even by being absorbed through our skin. Indeed, the Centers for Disease Control and Prevention reported that 92% of Americans age 6 or older test positive for BPA–a sign of just how common the chemical is in our plastic universe.

Scientists like vom Saal argue that BPA and phthalates are different from other environmental toxins like lead and mercury in that these plastic ingredients are endocrine disrupters, which mimic hormones. Estrogen and other hormones in relatively tiny amounts can cause vast changes, so some researchers worry that BPA and phthalates could do the same, especially in young children. Animal studies on BPA found that low-dose exposure, particularly during pregnancy, may be associated with a variety of ills, including cancer and reproductive problems. Some human studies on phthalates linked exposure to declining sperm quality in adult males, while other work has found that early puberty in girls may be associated with the chemicals.

Does that mean even today’s minuscule exposure levels are too much? The science is still murky, and human studies are few and far from definitive. So while Canada and the Democratic Republic of Wal-Mart are moving to ban BPA in baby bottles, the Food and Drug Administration maintains that BPA products pose no danger, as does the European Union. Even so, scientists like Mel Suffet, a professor of environmental-health sciences at the University of California, Los Angeles, say avoiding certain kinds of plastics is simply being better safe than sorry.

As researchers continue to examine plastic’s impact on our bodies, there’s no doubt that cutting down on the material will help the environment. Plastic makes up nearly 12% of our trash, up from 1% in 1960. You can literally see the result 1,000 miles (1,600 km) west of San Francisco in the Great Pacific Garbage Patch, a swirling mass of plastic debris twice the size of Texas. The rising cost of petroleum may get plastic manufacturers to come up with incentives for recycling; current rates stand at less than 6% in the U.S. But the best way to reduce your plastic impact on the earth is simply to use less.

Here’s how. You can avoid plastic bottles and toys labeled with the numbers 3 or 7, which often contain BPA or phthalates, and steer clear of vinyl shower curtains and canned foods–especially those with acidic contents like tomatoes. Vom Saal counsels that the cautious should also avoid heating plastic in microwaves. But get rid of the stuff altogether? “It’s hard to go all the way,” says Haegele, who, 10 months into her experiment, is leading a mostly plastic-free life. Although she still uses a plastic toothbrush, she’s experimented with her own toothpaste (made of baking soda, cinnamon and vodka; for the recipe, go to her blog, lifelessplastic.blogspot.com She has used vinegar for conditioner and is searching for a decent shampoo that doesn’t come in a plastic bottle. She has tried soaplike bars of shampoo, but they make her hair feel sticky. Plus, they sometimes come wrapped in–you guessed it–plastic.

 

February 28, 2011

Do you Know How are Plastics Produced?

Plastic is a polymer (which are large molecules), that consists of a long repeating chain of smaller molecules, which are called monomers.

Monomers are made of atoms, and easily extracted from organic sources, and fall into the class of chemicals known as petrochemicals. 

Plastics are produced by a process called polymerization.

In this process, thousands of monomers are joined together to form a polymer chain.

Common monomers used in the production of plastics, such as vinyl acetate, styrene, butadiene and vinyl chloride, are extracted from crude oil or natural gas.

In the world of “plastics”, there are two main types – thermosetting plastics and thermo-plastics.

Both of these main types are produced by pouring liquid monomers into molds, and they undergo a process called polymerization.

The thermosetting plastic type is permanent once molded, while the thermoplastic type will melt under heat.

The monomer liquid is superheated during the molding process, which causes polymerization to occur, and we end up with a product that is uniform and solid.

Some of the well known plastic products on the market today include: Formica, Teflon, Tupperware, Nylon, Synthetic Rubber and PVC.

Plastic is the most widely used synthetic in the world.

January 30, 2011

Choose your Water Bottle of Plastic very carefully

Choose your water bottles very carefully in order to prevent chemicals in the plastic from leaching into your water. So, which plastic water bottles don’t leach chemicals?

Plastic water bottles are very convenient for carting water around when we are on the go, as they don’t break if we drop them. However, it is worth paying attention to the type of plastic your water bottle is made of, to ensure that the chemicals in the plastic do not leach into the water.

If you taste plastic, you are drinking it, so get yourself another bottle. To be certain that you are choosing a bottle that does not leach, check the recycling symbol on your bottle. If it is a No.2 HDPE (high density polyethylene), or a No.4 LDPE (low density polyethylene), or a No.5 PP (polypropylene), your bottle is fine.

The type of plastic bottle in which water is usually sold is usually a No.1, and is only recommended for one time use. Do not refill it. Better to use a reusable water bottle, and fill it with your own filtered water from home and keep these single-use bottles out of the landfill.

Unfortunately, those fabulous colourful hard plastic lexan bottles made with polycarbonate plastics and identified by the No.7 recycling symbol, may leach BPA. Bisphenol A is a xenoestrogen, a known endocrine disruptor, meaning it disturbs the hormonal messaging in our bodies.

Synthetic xenoestrogens are linked to breast cancer and uterine cancer in women, decreased testosterone levels in men, and are particularly devastating to babies and young children. BPA has even been linked to insulin resistance and Type 2 Diabetes. For more of the science on the effects of BPA on our endocrine system etc.

See these studies: Environmental Health Perspectives Journal. Nalgene, the company that manufactures the lexan water bottles also makes #2 HDPE bottles in the same sizes and shapes, so we have a viable alternative. Order one at Nalgene. Unfortunately, most plastic baby bottles and drinking cups are made with plastics containing Bisphenol A.

In 2006 Europe banned all products made for children under age 3 containing BPA, and as of Dec. 2006 the city of San Franscisco followed suit. In March 2007 a billion-dollar class action suit was commenced against Gerber, Playtex, Evenflo, Avent, and Dr. Brown’s in Los Angeles superior court for harm done to babies caused by drinking out of baby bottles and sippy cups containing BPA. So, to be certain that your baby is not exposed, use glass bottles.

Check the recycling numbers on all your plastic food containers as well, and gradually move to storing all food in glass or ceramic. Store water in glass or brass if possible, and keep it away from direct sunlight.

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