Crystallizing ability

Optional) Crystallization robot to dispense protein and fragments for co-crystallization. Ability to do small volume drops is very desirable. 

DSC measurements showed that the crystallization ability of this interphase region was reduced by the silane modification of the glass beads. Despite an increase in the amount of amorphous material with increasing number of silane layers, a decrease in the intensity of the fourth lifetime was observed. This decrease in the free volume is in accordance with the earlier observed reduced mobility in the interphase region measured by dynamic-mechanical spectroscopy in the melt state [9,10] and creep and stress relaxation measurements in the solid state [12]. 

Good crystallization ability of the (S)-25-DBTA complex gave a possibility for preparation (S)-25 in a through process . In that case, diastereoisomeric complex formation was accomplished starting from the crude reaction mixture of ( )-25 and the residue of the monomeric phosphine oxide was recycled into the previous oxidative coupling reaction from the filtrate of the crystalline diastereoisomeric complex. [34]... 

Studies dealing with the influence of MWD on the toughness of P-PP are sparse. A metallocene P-PP, the archetype of a material with a narrow polydispersity (PI 2-3), was recently shown to exhibit a lower relative increase of the fracture resistance (between its non-nucleated and / -modified versions) than its Ziegler-Natta (ZN) homologue (PI 5-6) [117]. This result was attributed to the worse crystallization ability of a single-site grade—resulting in... 

The Isolation Technique Chromatography. Two alternatives are possible either to isolate the primary Hilbert-Johnson intermediates, i.e., l-peracylglycosyl-4-alkoxy-2(lH)-pyrimidinones, or to treat them with alcoholic hydrogen chloride or alcoholic ammonia and separate the corresponding A-l-glycosyl derivatives of uracil or cytosine. The latter alternative has been used by the earlier authors more frequently because of the higher crystallization ability of... 

The crystallization ability of glass can be characterized by the following parameters ... 

The crystallinity of compounds often is not as expected, and there is no substitute for actually crystallizing a compound. In the generation of the glycine derivative 19 (Figure 11.14), the secondary amine salt 20 crystallizes and is removed from processing by a simple filtration [46]. The more basic tertiary amine 19 might be expected to bind the HBr and crystallize as the salt, but under these conditions the excess secondary amine crystallizes preferentially as the HBr salt. Predictions of crystallizing ability should always defer to experimental data. 

X, Xc, and X indicate 3HV mol% content of whole P(3HB-3HV) copolymers, that in the crystalline region, and that in the non-erystalline region, respectively. indicates the crystallizing ability of the secondary component. "A indicates the degree of crystallinity. AHf indicates the heat of fusion of the pure crystal. (Reproduced from Ref. [53] with permission). 

The crystallizing ability of the minor component as the crystalline component in the lattice of the major component can be discussed quantitatively by the term E defined as follows when a crystal has the P(3HB) lattice, i.e., X is smaller than ca. 40%, E is given by... 

Table 3.1. Influence of of the amorphous component on the crystallization ability of the crystallizable component in miscible binary polymer blends...

Pluta [49] studied the structure and properties of PLA/MMT nanocomposites and showed an effective enhancement of MMT dispersion with prolongation of the blending time (from 6 to 30 min). They stressed that this was possible due to strong interaction between PLA-MMT and shearing forces during melt compounding. The nanostructure was induced by the intercalation followed by tactoids formation and exfoliation of MMT, as confirmed by TEM analysis and XRD. The studies performed also clearly revealed the influence of MMT s dispersion in the PLA matrix on the physical properties of the nanocomposites formed as the improved MMT s dispersion (at their constant concentration) had increased the thermal stability of the nanocomposites under oxidative and nonoxidative conditions was improved with MMT s dispersion. Besides that, the crystallization ability of PLA also improved with incorporation of MMT. 

The crystallization rate and the range of temperatures at which crystallization may occur depend on the glass transition temperature. It was found that a small addition of plasticizer (10 wt%) enhanced crystallizing abilities of polyimide. ... 

An increase in the crystallinity [77,133,137] or interfacial crystallinity have been considered other parameters for improving the mechanical response of polymers [170]. Oxidized NDs effectively enhanced the crystallization ability of PVA, indicating the crystalline regions may act as physical crosslinks or filler particles. The increased crystallinity and reinforcing effect of oxidized NDs increased the storage modulus of all the PVA nanocomposites to a higher degree than that of neat PVA [48]. Sahoo... 

An Inportant result of the randomization is the lost of crystallization ability of the matrix, as demonstrated by DSC, WAXS, SAXS and solubility measurements performed on binary and ternary blends of PET, PA 6 and polybutylene terephthalate (PBT) 7-9 ... 

On the basis of the above considerations, one can conclude that by following the approach described a new type of composites - microfibrillar reinforced ones can be obtained from all thermoplastic polymers. Using blends of condensation polymers, a strong self-compatibillzing effect can be achieved due to Interfaclal chemical interactions. Opportunities are also available for continuous controllable changes of the chemical composition and crystallization ability of the matrix. The formation of an interphase drastically Improves the mechanical integrity of drawn blends. 

No changes in the glass transition temperature of PLA by the addition of NR were observed, confirming the immiscible behaviour of these blends. In addition, it was demonstrated that the NR acted as a nucleating agent enhancing the crystallization ability of PLA since a cold-crystallization exothermic peak was observed in the DSC heating curves. 

Physical or chemical modification of commercial polymers is one of the most promising routes for obtaining polymer materials with tailored properties. The blending of two or more homopolymers is a typical example of physical modification. The homopolymer compatibihty in the blends is of prime importance for their final properties. Compatibility is directly related to the chemical nature and crystallization ability of homopolymers as well as to the conditions of preparation and processing of the blends. Since polymers are in general incompatible, there is a constant search for means of improving their compatibility and/or suppression of incompatibility. 

Some of the energy conversion effects can be two-way effects. For example, the piezoelectric effect was defined based on the crystals ability to convert stress into electric charge. 

Chlorinated polyethylene elastomer (CPE) has been produced by the introduction of chlorine atoms onto the polyethylene backbone in order to reduce the crystallization ability of polyethylene. In addition, the enhancement in resistance to hydrocarbon oil, heat and weathering is also achieved. To gain desired properties of the final products, CPE has been blended with many polymers, including polyvinyl chloride, styrene-acrylonitrile and polyurethane. Compared to NR, CPE is relatively expensive and therefore the blending of CPE/NR is one of methods to reduce the production cost of the final products requiring CPE properties. Some researchers from Thailand are working with this kind of blend. ... 

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