Amorphous high-strength materials

Amorphous stereotactic polymers can crystallise, in which condition neighbouring chains are parallel. Because of the unavoidable chain entanglement in the amorphous state, only modest alignment of amorphous polymer chains is usually feasible, and moreover complete crystallisation is impossible under most circumstances, and thus many polymers are semi-crystalline. It is this feature, semicrystallinity, which distinguished polymers most sharply from other kinds of materials. Crystallisation can be from solution or from the melt, to form spherulites, or alternatively (as in a rubber or in high-strength fibres) it can be induced by mechanical means. This last is another crucial difference between polymers and other materials. Unit cells in crystals are much smaller than polymer chain lengths, which leads to a unique structural feature which is further discussed below. 

Polymerized epoxy adhesives are amorphous and highly crosslinked materials. This microstructure results in many useful properties such as high modulus and failure strength, low creep, and good chemical and heat resistance. However, the structure of epoxy resins also leads to one undesirable property—they are relatively brittle materials. As such, epoxy adhesives tend to have poor resistance to crack initiation and growth, which results in poor impact and peel properties. In sealant formulations, epoxy resins do not often provide the degree of elongation or movement that is required for many applications. 

Amorphous thermoplastic introduced in 1982. The material is characterized by high strength and rigidity at elevated temperatures, long-term heat resistance, and highly stable dimensional and electrical properties. 

Advances in the production of amorphous and nanostructured powders over the past decade have given materials scientists new opportunities for the creation of high strength bulk materials. Bulk material with extraordinary properties should result if such powders can be consolidated without significant changes to the microstructure, and strong interparticle bonding is achieved. There are several methods available to consolidate... 

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