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Polycarbonate is commonly used in eye protection, as well as in other projectile-resistant viewing and lighting applications that would normally indicate the use of glass, but require much higher impact-resistance. Polycarbonate lenses also protect the eye from UV light.
A polycarbonate is an oxocarbon dianion consisting of a chain of carbonate units, where successive carbonyl groups are directly linked to each other by shared additional oxygen atoms. That is, they are the conjugate bases of polycarbonic acids , the conceptual anhydrides of carbonic acid , or polymers of carbon dioxide .
Poly(trimethylene carbonate) (PTMC) is an aliphatic polycarbonate synthesized from the 6-membered cyclic carbonate, trimethylene carbonate (1,3-propylene carbonate or 1,3-Dioxan-2-one). Trimethylene carbonate (TMC) is a colorless crystalline solid with melting point ranging between 45°C and 48 °C and boiling point at 255°C (at 760 mmHg).
A water bottle. Worldwide, 480 billions of plastic drinking bottles were sold in 2017 (and fewer than half were recycled). [1] A plastic bottle of antifreeze Large plastic bottles of water. A plastic bottle is a bottle constructed from high-density or low density plastic. Plastic bottles are typically used to store liquids such as water, soft ...
Meanwhile, 50% to 80% of debris in marine areas is plastic. [57] Plastic is often used in agriculture. There is more plastic in the soil than in the oceans. The presence of plastic in the environment hurts ecosystems and human health. [59] Research on the environmental impacts has typically focused on the disposal phase.
Most of the plastics found were nano-sized shards or flakes of polyethylene, which is used in plastic bags, plastic food wrapping, and plastic water bottles. It's unclear what effect this may have ...
Image credits: Tweetystraw However, there is a limit to what they can solve, notes Clark. “As shown by the crow species, the New Caledonian crow, which makes and uses probing tools in the wild ...
Their addition allows to decrease the water-to-cement ratio of concrete or mortar without negatively affecting the workability of the mixture. It enables the production of self-consolidating concrete and high-performance concrete. The water–cement ratio is the main factor determining the concrete strength and its durability. Superplasticizers ...