2017年1月11日星期三

The common polymers

Polymer refers to macro molecular compound, one or several structural units connected by covalent bonding of high molecular weight compounds. Most natural polymers exist in the organism, and it is essential for life.

These natural polymers some are important nutrients, such as protein, starch; some can be used for daily necessities, such as natural rubber, cellulose; some can control our genetic in organisms, such as nucleic acid.

Synthetic polymers are usually high molecular weight organic compounds. Compared to natural polymers, its structure is simple, usually a maximum of two different units, such as nylon, polyvinyl chloride (PVC), etc.

There are common polymers, such as polyurethane. In addition to urethane, polyurethane macromolecules also contain ether, ester, urea, biuret, urea acid ester and other groups. According to the different raw materials, there has a different nature of the products, they usually are polyester and polyether-type. It can be used in the manufacture of plastics, rubber, fibers, rigid and flexible foams, adhesives and coatings.

Poly ethylene glycol and Poly ethylene oxide are made by polymerization of ethylene oxide, but the synthesis method and the molecular weight is different. Generally, PEG refers to polymers of molecular weight in 500-20000, molecular weight of PEO is 100000-5000000. From moleculars perspective, the main difference of this two is molecular volume different, second is synthesis of catalysts and way of different. Generally, molecular chain ends of PEG are hydroxy, but one end of PEO molecular is hydroxy, the other is alkyl. Due to the features of polymer material, different molecular volume will led to larger differences of performance. It can be said as two different materials from using, but it is not appropriate to say the two materials are fundamental different.

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Polymer refers to high molecular weight (usually up to 104~106) compounds that through covalent bonds repeated connection of many of the same, simple structure.

Classification of polymers can be from different angles, such as single sources, synthesis, end use, heating, polymer structure and so on. If you have interest in polymer and need more details, please read more here now.
Source: https://www.okchem.com/news/the-common-polymers/

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