These chains are called polymers. Polymers often are made of carbon and hydrogen and sometimes oxygen, nitrogen, sulfur, chlorine, fluorine, phosphorous, or silicon. Although there are many polymers, plastics in general are lightweight with significant degrees of strength. Plastics can be molded, extruded, cast and blown into seemingly limitless shapes and films or foams or even drawn into fibers for textiles. Many types of coatings, sealants and glues are actually plastics, too.
Step Bottles go for labeling and filling! Bottles go to be labeled with their desired paper labels and then filled with the material they are made for. Whether it be peanut butter or water! With all of the plastic products that surround us, they can be hard to avoid. There are places in Canada banning single use products like straws, and some Universities have ban bottled water.
The main reason for this being environmental consciousness. Previously it has been mentioned in other blog posts and social media posts, that plastic never really leaves the environment once it has been produced.
It only breaks down into smaller and smaller pieces, called microplastics and it is forever in the ground and waterways. But what are the negative consequences of plastics on our health while we are using plastics, even before we dispose of them? In and out of the news BPA has been mentioned numerous times.
BPA stands for bisphenol A. BPA is an industrial chemical that has been used to make certain plastics and resins since the s. BPA is found in polycarbonate plastics and epoxy resins. Polycarbonate plastics are often used in containers that store food and beverages, such as water bottles.
According to The Mayo Clinic, exposure to BPA is a concern because of possible health effects of BPA on the brain, behavior and prostate gland of fetuses, infants and children. There is currently no law saying that products cannot be made with BPA nor do they have to disclose that if there is BPA in a plastic product. Toggle navigation. Twitter Facebook Instagram Language Search.
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When the source of oil beneath the surface of the Earth is identified, holes are drilled through the rocks in the ground to extract oil.
Extraction of oil - Oil is pumped from underground to the surface where tankers are used to transport the oil to the shore. Oil drilling can also take place under the ocean using support from platforms. Different size pumps can produce between 5 - 40 litres of oil per stroke Figure 1. Refining of oil - Oil is pumped through a pipeline that can be thousands of miles long and transported to an oil refiner Figure 1.
Spillage of oil from the pipeline during transfer can have both immediate and long-term environmental consequences but safety measures are in place to prevent and minimise this risk. Distillation of crude oil and production of petrochemicals - Crude oil is a mixture of hundreds of hydrocarbons that also contains some solids and some gaseous hydrocarbons dissolved in it from the alkane family mainly it is CH 4 and C 2 H 6 , but it can be C 3 H 8 or C 4 H Crude oil is first heated into a furnace then the resultant mixture is fed as a vapour to the fractional distillation tower.
The fractional distillation column separates the mixture into different compartments called fractions. There exists a temperature gradient in the distillation tower where the top is cooler than the base. The mixture of liquid and vapour fractions gets separated in the tower depending on their weight and boiling point boiling point is the temperature at which the liquid phase changes into gaseous.
When the vapours evaporate and meet a liquid fraction whose temperature is below the boiling point of vapor, it partly condenses. These vapours of evaporating crude oil condense at different temperature in the tower. Vapours gases of the lightest fractions gasoline and petroleum gas , flow to the top of the tower, intermediate weight liquid fractions kerosene and diesel oil distillates , lingers in the middle, heavier liquids called gas oils separate lower down, while the heaviest fractions solids with the highest boiling points remain at the base of the tower.
Each fraction in the column contains hydrocarbons with a similar number of carbon atoms, smaller molecules are towards the top and longer molecules nearer the bottom of the column Ref. In this way, petroleum is decomposed into petroleum gas, gasoline, paraffin kerosene , naphtha, light oil, heavy oil, etc.
After the distillation step, the obtained long chain hydrocarbons are converted into hydrocarbons that can then be turned into many important chemicals which we use for the preparation of a wide range of products applicable from plastic to pharmaceuticals. Steam cracKing uses high temperature and pressure to break the hydrocarbons long chains without a catalyst, whilst catalytic cracking adds a catalyst which allows the process to occur at lower temperatures and pressures.
The raw material used by the petrochemical industry is mainly naphtha and natural gas from oil refining operation in the petrochemical feedstock. Steam cracking uses the feedstocks from hydrocarbons mixture from various fractions such as reactant gases ethane, propane or butane from natural gas , or liquids naphtha or gas oil Figure 4.
Naphtha is a mixture of C 5 to C 10 hydrocarbons obtained from the distillation of crude oil. For example, decane hydrocarbon is cracked down into products such as propylene and heptane where the former is then used to make poly propylene Figure 5. Figure 5. Representation of Cracking of decane to convert into propylene and heptane. Raw materials molecules are converted into monomers such as ethylene, propylene, and butene and others.
All these monomers comprise double bonds so that the carbon atoms can subsequently react to form polymers. Polymerisation - hydrocarbon monomers are then linked together by chemical polymerisation mechanism to produce polymers. Polymerisation process generates thick, viscous substances as resins, which are employed to make a plastic product.
If we look at a case of ethylene monomer here; ethylene is a gaseous hydrocarbon. When it is subjected to heat, pressure and a certain catalyst, it joins together into long, repeating carbon chains. These joined molecules polymer is a plastic resin known as polyethylene PE.
Production of PE based plastic —poly ethylene is processed in a factory to make plastic pellets. The pellets are poured into a reactor, melted into a thick liquid to cast into a mould. The liquid cools down to harden into a solid plastic and produce a finished product. Processing of polymer also includes the addition of plasticizers, dyes and flame-retardant chemicals.
Synthetic plastic is made by a reaction known as polymerisation, which can be performed in two different ways:. Addition polymerisation : Synthesis includes adding together monomers in a long chain. One monomer connects to the next and so on, when a catalyst is introduced, in a process known as chain growth polymers, adding one monomer unit at a time. Some addition polymerisation reactions are considered to create no side-products and the reaction can be performed in the vapour phase i.
Examples: polyethylene, polypropylene, polyvinyl chloride and polystyrene. Condensation polymerisation : In this case, two monomers combine to form a dimer two units by releasing a byproduct. Dimers can then join to form tetramers four units and so on. These byproducts are necessary to be removed for the success of the reaction.
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