Polymer synthesis Polymer

the repeating unit of polymer polypropylene

polymerization process of combining many small molecules known monomers covalently bonded chain or network. during polymerization process, chemical groups may lost each monomer. case, example, in polymerization of pet polyester. monomers terephthalic acid (hooc-c6h4-cooh) , ethylene glycol (ho-ch2- ch2-oh) repeating unit -oc-c6h4-coo-ch2-ch2-o-, corresponds combination of 2 monomers loss of 2 water molecules. distinct piece of each monomer incorporated polymer known repeat unit or monomer residue.

laboratory synthetic methods divided 2 categories, step-growth polymerization , chain-growth polymerization. essential difference between 2 in chain growth polymerization, monomers added chain 1 @ time only, such in polyethylene, whereas in step-growth polymerization chains of monomers may combine 1 directly, such in polyester. however, newer methods such plasma polymerization not fit neatly either category. synthetic polymerization reactions may carried out or without catalyst. laboratory synthesis of biopolymers, of proteins, area of intensive research.

biological synthesis


microstructure of part of dna double helix biopolymer

there 3 main classes of biopolymers: polysaccharides, polypeptides, , polynucleotides. in living cells, may synthesized enzyme-mediated processes, such formation of dna catalyzed dna polymerase. synthesis of proteins involves multiple enzyme-mediated processes transcribe genetic information dna rna , subsequently translate information synthesize specified protein amino acids. protein may modified further following translation in order provide appropriate structure , functioning. there other biopolymers such rubber, suberin, melanin , lignin.

modification of natural polymers

naturally occurring polymers such cotton, starch , rubber familiar materials years before synthetic polymers such polyethene , perspex appeared on market. many commercially important polymers synthesized chemical modification of naturally occurring polymers. prominent examples include reaction of nitric acid , cellulose form nitrocellulose , formation of vulcanized rubber heating natural rubber in presence of sulfur. ways in polymers can modified include oxidation, cross-linking , end-capping.

especially in production of polymers, gas separation membranes has acquired increasing importance in petrochemical industry , relatively well-established unit operation.

the process of polymer degassing necessary suit polymer extrusion , pelletizing, increasing safety, environmental, , product quality aspects. nitrogen used purpose, resulting in vent gas composed of monomers , nitrogen.