Polymer , generally morphology

As pointed out above, the semicrystalline polymer can be considered as a two-phase composite of amorphous regions sandwiched between hard crystalline lamellae (Fig. 4.2(a)). Crystal lamellae ( c) are normally 10-25 nm thick and have transverse dimensions of 0.1-1 pm while the amorphous layer thickness, a, is 5-10 nm. As mentioned in the previous section, melt-crystallized polymers generally exhibit a spherulitic morphology in which ribbon-like lamellae are arranged radially in the polycrystalline aggregate (Bassett, 1981). Since the indentation process involves plastic yielding under the stress field of the indenter, microhardness is correlated to the modes of deformation of the semicrystalline polymers (see Chapter 2). These... 

In reality, for a block copolymer like PS-b-PI, the degree of polymerisation is much greater than 47 so phase separation between the two polymer blocks would occur regardless of the conditions. The general morphological changes that accompany PS and PI compositional variation are listed as follows ... 

It is expected that because of the built-in disorder, such as chain ends in low molecular weight polymers and morphological and structural regions in general, the... 

The general morphology of crystalline polymers is now well known and understood and has been described by Geil [2], Keller [3], Wunderlich [4], Grubb [5,6], Uhlmann [7] and Bassett [8,9]. The text by Bassett [8] is a good overview... 

The cell-polymer Interaction Is believed to be mainly dependent on the physicochemical properties of the material surface, surface free energy, hydrophlllcity, and surface morphology [2-6]. The common polymers generally do not possess proper surfaces as required for biomedical applications. A functional blomaterlal... 

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