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Other monomer units, such as formaldehyde hydrates or simple aldehydes, are able to polymerize themselves at quite low temperatures (ca. −80 °C) to form trimers; [3] molecules consisting of 3 monomer units, which can cyclize to form ring cyclic structures, or undergo further reactions to form tetramers, [3] or 4 monomer-unit compounds.
Polymer chemistry is a sub-discipline of chemistry that focuses on the structures, chemical synthesis, and chemical and physical properties of polymers and macromolecules. The principles and methods used within polymer chemistry are also applicable through a wide range of other chemistry sub-disciplines like organic chemistry , analytical ...
2007: Metabolix inc. market tests its first 100% biodegradable plastic called Mirel, made from corn sugar fermentation and genetically engineered bacteria. (Digregorio 2009) [ 100 ] 2012: A bioplastic is developed from seaweed proving to be one of the most environmentally friendly bioplastics based on research published in the journal of ...
For lack of nitrogen and phosphorus they produce a kilogram of PHA per three kilograms of sugar. The simplest and most commonly occurring form of PHA is the fermentative production of poly-beta-hydroxybutyrate [poly(3-hydroxybutyrate), P(3HB)], which consists of 1000 to 30000 hydroxy fatty acid monomers.
The physical properties [31] of polymer strongly depend on the length (or equivalently, the molecular weight) of the polymer chain. [32] One important example of the physical consequences of the molecular weight is the scaling of the viscosity (resistance to flow) in the melt. [33]
A monomer with functionality of 3 or more will introduce branching in a polymer and will ultimately form a cross-linked macrostructure or network even at low fractional conversion. The point at which a tree-like topology transits to a network is known as the gel point because it is signalled by an abrupt change in viscosity.
Polymer engineering is generally an engineering field that designs, analyses, and modifies polymer materials. Polymer engineering covers aspects of the petrochemical industry, polymerization, structure and characterization of polymers, properties of polymers, compounding and processing of polymers and description of major polymers, structure property relations and applications.
Plastics per se have low toxicity due to their insolubility in water and because they have a large molecular weight. They are biochemically inert. Additives in plastic products can be more problemative. [45] For example, plasticizers like adipates and phthalates are often added to brittle plastics like PVC to make them pliable. Traces of these ...