Amorphous structural domains, glass transitions

The structure correct quantitative model is necessary for analytic intercommunication between polymers structure and properties obtaining. As it has been noted above, the cluster model of polymers amorphous state structure will be used with this purpose [106, 107], The notion of local (short-order) order forms the basis of this model and loeal order domains (clusters) relative fraction is connected with glass transition temperature according to the following percolation relationship [107] ... 

In Sect. 7.2, we described how the morphology of semi-crystalline polymers was made up of coexisting crystalline domains and amorphous regions. Molecular motions of about ten bonds involved in the glass transition can happen in the amorphous phase. They will concern only those parts of the chains lying in this phase. Consequently, semi-crystalline polymers have a glass transition temperature. It has the same dependence on time (frequency) and chemical structure as in totally amorphous compounds. 

Polymers can exhibit a hierarchical organization of structure at four successive levels, the molecular, nano-, micro-, and macrolevel [33, 34], On the scale of tens of microns, semicrystalline polymers contain spherulites, the spherulites have a lamellar texture, and the molecules within the lamellae are organized in crystals and amorphous domains. Amorphous polymers are structured on the molecular and macroscopic scale only [34]. Thermoplastic SMPs are usually phase-segregated materials, i.e., they consist of at least two different domains, which are related to different thermal transition temperatures (Tinms)- Therein hard domains have a TJrans (glass transition temperature Tg or melting temperature 7]n) usually much higher than room temperature and determine the permanent shape, while switching domains show a lower thermal transition (Tg or 7]n). SMP networks contain chemical crosslinks instead of hard domains to fix the permanent shape. 

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