Interfibrillar phase

On drying a rigid gel the aqueous phase enmeshed in the feltlike fibrils begins to evaporate, the gel is sufficiently rigid as not to collapse as the interfibrillar spaces become emptied of water and filled with air. Such a gel will, on immersion in other solvents, e.g. toluene, benzene or alcohols, imbibe the liquid. 

PVDF/iPEMA shows an LCST phase behavior (LCST =183 °C), the experiments were performed on blends prepared and studied below this temperature A blend of 1-octene LLDPE fractions with different short-chain branching contents was investigated, i.e., 3 and 33 methyl groups per 1000 carbon atoms Rapid crystallization conditions, interfibrillar segregation occurred in blends with a PEI concentration below 50 % at highta- ctmtents of the amorphous component, interspherulitic segregation was observed Slow crystallization conditions... 

The main characteristic feature of highly oriented semicrystalline homopolymers is the existence of a regular sequence of crystalline and amorphous layers placed normally to the orientation axis and giving rise to the long spacing in SAXS. They are linked by a large number of tie molecules. Another peculiarity of oriented polymers is the existence of microfibrils aligned parallel to the orientation axis, as concluded mainly from microscopic observations. Farther, it is known that the amorphous phase is situated mainly inside the fibrils between the crystalline lamellae (intrafibrillar amorphous phase) y whereas a relatively small amount exists between the fibrils interfibrillar amorphous phase). The latter equals 10-15% for poly (ethylene terephthalate) [9] and PBT [10]. 

The structure of oriented multi-block crystallizable copolymers should be basically the same. However, some peculiarities are caused by the limited length of the crystalhzable blocks affecting the interfibrillar and intrafilillar amorphous phase distribution, as weU as the number of tie molecules, discussed below. 

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