Interfibrillar region

Oxidative processes are localized in amorphous interlayers, in interfibrillar regions and others. Crystallinity and crystals sizes increase at initial stages of oxidation [303] it also means that oxidation is localized in amorphous part. Destructive decay of passing macromolecules in amorphous interlayers release them and facilitates folding of chains into crystals. Destruction and amorphicity of crystals takes place only at deep stages of oxidation. Solubility of oxygen in polymer depends not only on polymer crystallinity but on microstructure of amorphous or defect sections. 

It is suggested that the plasticization of a low density polyethylene, LDPE, occurs inside the spherulitic crystallite in the interlamellar and interfibrillar regions. DOP-plasticized LDPE melts at lower temperatures as a result of plasticization. ... 

Fig. 10. Schematic representation of segregation of amorphous components in partially crystalline polymer blends depicting the location of residual crystallisable polymer and non-crystallisable polymer in the interlamellar and interfibrillar regions within spherulites and interspherulitic locations. Solid lines represent the crystallisable component and dotted lines the non-crystallisable component taken from [60]...

The infrared spectra (down to 60 cm ) of (SN), and brominated (SN), have been compared to their Raman spectra, and specific vibrational assignments are proposed based on these measurements. The vibrational spectra indicates that, in the brominated species, the bromine is located between the (SN), chains and also in the interfibrillar regions, both Brj and Brj species appeared to be present. 

With increasing neat PVAc content, the heat of fusion decreases and die melting peaks shift to lower temperature in PLA/PVAc blends. The interaction parameters exhibit negative values for up to 10% hydrolyzed PVAc copolymer, but the values increase to positive ones with increasing the degree of hydrolysis. SAXS analysis and polarized optical microscopy observation indicate that a considerable amoimt of PVAc components is located in the interlamellar region. But P(VAc-co-VA) component is expelled out of the interfibrillar regions of the PLA spherulites in PLA/P (VAc-co-VA) blends. 

This phenomenon was discussed in terms of the possible direct correlations between stepwise creep and fiber morphology, namely, of micro-shear displacements of various fibrillar elements in a stick-slip mode. It was shown that the fibrillar units were weakly connected and loosely packed in these fibers interfibrillar regions contained pores and a small number of tie molecules. The length of microfibrils has been estimated to be microns, whereas the length of macrofibrils reached lOOpm and more. These sizes correlate satisfactorily with the observed deformation steps. Of course, this approach (slippage of fibrils upon creep) did not exclude the participation of the intracrystalline slip events and the process of scission of overstressed interfibrillar tie molecules in jump-like creep. Submicro- and microcrack formation could also contribute, to some extent, to creep heterogeneity and the total deformation of fibers [314]. 

The PEO/EMAA and PEO/SHS blends exhibit volume-filling spherulites for all compositions examined in this part of the study (i.e., 20%). These observations, in concert with SAXS results, indicate at least partial exclusion of the diluent into regions between lamellar stacks at these compositions. The distribution of the second polymer between the interlamellar and interfibrillar regions can be estimated using measured bulk crystallinities and correlation function parameters as follows. The volume fraction of lamellar stacks is determined from the bulk and linear crystallinities (v, average electron density difference between crystalline and interlamellar amorphous regions can be determined using eqn. 2. 

The corresponding volume fractions of the diluent polymer in interlamellar and interfibrillar regions (i.e., ILd and IFd) can be calculated fiom... 

The behavior of the weakly-interacting PEO blends seems to suggest that the mobility of the amorphous component at T. determines diluent location relatively high Tg PMMA is trapped between crystal lamellae whereas low Tg PVAc is able to diffuse from the growth fiont and is located partially in interfibrillar regions. 

Poly(cyclohexyl acrylate) was shown to be miscible with PS with ucst behavior [720]. Random copolymers of cyclohexyl acrylate with n-butyl acrylate showed miscibility with PS above 50% cyclohexyl acrylate[721]. Poly(cyclohexyl methacrylate)/isotactic PS blends showed miscibility based on calorimetry and NMR studies [722]. The NMR results showed homogeneous behavior at a scale of 2.5-3.5 nm. Poly(4-trimethylsilyl styrene) miscibility with polyisoprene was observed with a lest behavior (critical temperature = 172 ° C at degree of polymerization of 370) [723]. The interaction parameter, showed the following relationship = 0.027—9.5/T. Isotactic and syndiotactic polystyrene both exhibit crystallinity, whereas atactic polystyrene is amorphous. Atactic PS/isotactic PS blends exhibited crystallization kinetics, which decreased linearly with atactic PS addition indicating miscibility [724]. The TgS of aPS and iPS are identical, thus Tg methods could not be employed to assess miscibility. Atactic PS/syndiotactic PS blends were also noted to be miscible with rejection of atactic PS in the interfibrillar region between the lamellar stacks of sPS [725]. 

The regions between the microfibrils are especially pronounced with solvent-spun fibers. Even cavity pipes, called microvoids, may develop. These interfibrillar regions are good for dyeing but may cause the fiber to fibrillate. 

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