PPCNs

Casein enrichment of cheese milk significantly improves the rennet coagulability and the productivity of cheese plants, especially those producing hard cheeses [100]. For instance, the rennet coagulation time of a 3% native PPCN solution is reduced by 53% compared to that of raw milk, and the gel fimmess after 30 min is increased by more than 50% (Pierre et al., 1992, cited in Ref. [100]). 

Calcium salt trihydrate, C1(HMCaN4Of. 3H,0, crystals. Slightly hitter taste. One gram dissolves in about 40 ml water. Practically insol in alcohol. Aq solns are alkaline to litmus. Solns are unstable and ppcn occurs on boiling. LDM in rats, rabbits (mg/kg) 110, 110 i.p. (Fitch, Tatum). 

A nanocomposite made using modified polypropylene and Cl8-Mt is called a Polypropylene-Clay Nanocomposite (PPCN). Because clay min-... 

Fig. 22 TEM images (a) PPCN(U1010+C18-Mt) (b) PPCN(U1001+C18-Mt) (c) PPCN (PO1015+C18-Mt)...

Fig. 25 Results of dynamic viscoelastic measurements of PPCN and PO1015 (a) storage modulus (b) relative storage modulus of PPCN to PO1015...

Figure 28 shows the relationships between the amount of inorganics in the clay and the gas permeability coefficient. The gas permeabiUty coefficient decreased as the amount of added clay increased. The gas barrier performance of PPCN-5 increased by 1.7 times. It has been reported that the barrier performance of the nylon-clay nanocomposites and polymer-clay nanocomposites was improved. This barrier effect is explained as being attributed to the geometrical detour effect of the dispersed nanosized silicates. The barrier effect of PPCN, however, was smaller than that of the nylon-clay nanocomposites. hi the case of the nylon-clay hybrid, the addition of 1.8 wt % of mont-morillonite caused its hydrogen permeability to decrease to 70%. In the case of PPCN, about 3 wt % of montmorillonite must be added to obtain the same... 

Figure 31a and b show the TEM images. Exfoliated silicate layers are dispersed more widely and uniformly in the UlOOl-type PPCN (PP-I-U1001/C18-Mt) than in the UlOlO-type PPCN (PP-i-U1010/C18-Mt). Many silicate layers, whose interlayer distances were expanded to more than 5 nm, were also... 

Fig. 30 X-ray diffraction patterns (a) C18-Mt (b) U1010/Cl8-Mt (c) U1001/C18-Mt (d) PPCN(U1010/C18-Mt) (e) PPCN(U1001/C18-Mt) (f) PPCN(U1010+C18-Mt) (g) PPCN(U1001+C18-Mt) (h) PPCN(U1010+C18-Mc) (i) PPCN(U1001+C18-Mc)...

With UlOlO-type C18-Mt and C18-Mc, a peak associated with the layered structure of the silicate was observed around 20 = 0.8°. It is inferred from this that silicate layers with UlOlO intercalated are dispersed and that they maintain their layered structure. The interlayer distance for UlOlO-type PPCN (PP+U1010+C18-Mt) (Fig. 30f) is equivalent to that of the U1010/C18-Mt interlayer compound (Fig. 30b) which was fabricated using UlOlO and C18-Mt in the same proportions. Therefore, it is thought that UlOlO is selectively-intercalated between the layers of C18-Mt during mixing, even if polypropylene is mixed simultaneously. 

Figures 31c,d and e show the TEM images. With the U1001-type C18-Mt and C18-Mc, the dispersibihty of the sihcate layers was better than that in the UlOlO-type PPCN (PP-i-U1010-i-C18-Mt). The dispersibihty of the sihcate layers in specimens fabricated using a simultaneous mixing method was equivalent to that in specimens fabricated using clay interlayer compoimds.

Figures 33a and b show the relative storage moduli of the PPCN using montmorillonite and the PPCN using mica. The relative storage moduli of both the UlOlO and UlOOl specimens using mica were high over the whole temperature range.

All of the specimens exhibited the same or similar relative storage mod-uH at temperatures below Tg (10 °C). In the temperature range above Tg up to around 100 °C, specimens using mica exhibited a higher reinforcement effect. The relative storage modulus of the PPCN (PP+1001C8-Mt) using mica was twice that of MA2 at 80 °C. 

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