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Polymer morphology is a microscale property that is largely dictated by the amorphous or crystalline portions of the polymer chains and their influence on each other. Microscopy techniques are especially useful in determining these microscale properties, as the domains created by the polymer morphology are large enough to be viewed using modern ...
For a polymer to exhibit the thermally induced shape-memory effect, it must have anchor points for temporary and permanent shape. These can be physical (chain entanglements, crystals) or chemical (chemical crosslinking, curing, vulcanization). This effect in polymers depends on entropic forces and not on martensitic transitions like metals.
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. [1] [2] [3] There are many forms of polymerization [4] and different systems exist to categorize them.
Electrospinning shares characteristics of both electrospraying and conventional solution dry spinning [3] of fibers. The process does not require the use of coagulation chemistry or high temperatures to produce solid threads from solution. This makes the process particularly suited to the production of fibers using large and complex molecules.
The polymer chains associate by intermolecular forces, which weaken rapidly with increased temperature, yielding a viscous liquid. In this state, thermoplastics may be reshaped, and are typically used to produce parts by various polymer processing techniques such as injection molding , compression molding , calendering , and extrusion .
[1] [2] [4] One added benefits of using polymers prepared by interfacial polymerization is that several properties, such as pore size and interconnectivity, can be fined-tuned to create a more ideal product for specific applications. [1] [4] [5] For example, synthesizing a polymer with a pore size somewhere between the molecular size of ...
The simple structure of the molecule also gives rise to surface and chemical properties that are rare in high-performance polymers. For example, the polar groups in most polymers easily bond to water. Because olefins have no such groups, UHMWPE does not absorb water readily, nor wet easily, which makes bonding it to other polymers difficult ...
Polymers are composed of long molecular chains which form irregular, entangled coils in the melt. Some polymers retain such a disordered structure upon freezing and readily convert into amorphous solids. In other polymers, the chains rearrange upon freezing and form partly ordered regions with a typical size of the order 1 micrometer. [3]