Quenched films

When drawdown is high, the film may be uniaxially oriented and the properties of the final film isotropic. In the manufacture of strapping tape this effect is accentuated. If the cast or quenched film is to be used to feed an orientation tine, additional attention must be given to the amorphous—crystalline nature of the film ia the draw processes so that maximum strength can be achieved and uniform gauge and optical quality maintained. Slot casting is used for the orientation of these resins, polyesters, polyamides, and a variety of others. 

Figure 8. Comparison of the stress-strain properties of the press-quenched films of HBIB to those from the homopolymers HB and HI. Composition of each polymer is denoted by the butadiene content next to the graph.

Figure 4. Brillouin spectrum of a quenched film of 75% PVFS 25% PMMA by weight at 20°C...

Another class consists of extrusion immediately followed by an additional stage. This includes blow moulding, film blowing, quenched film forming, fibre spinning, and extrusion coating. 

Cast film is produced by extruding the melt from a slit die and cooling it either by contact with a chill roll or by quenching in a water bath. The most popular process used to produce the flat film is with the chill rolls. Chill roll lines can be arranged in different layouts to meet different requirements. Example is shown in Figure 5.7. Water chill tank or quench film is also a popular process. 

Figure 5.9 Simplified water quenched film line...

Three types of copoly(Y-n-alkyl L-glutamate)s with the combination of methyl-hexyl (MH), methyl-octyl (MO) and propyl-octyl (PO) were prepared by alcoholysis of PMLG in ethylene dichloride using p-toluenesulfonic acid as the catalyst at 60 °C. The thermotropic mesophase was detected by the iridescent cholesteric color which appeared by annealing at temperatures in the region 110 190 C. Also the circular dichroism due to the selective reflection was measured at room temperature for the quenched films. Only the films with the copolymer composition of about 50/50... 

Petrothene [Quantum]. TM for polypropylene resins for blown, cast, and water-quenched films, substrate coating, wire and cable coating, injection molding, blow molding, thermoforming, pipe extrusion, calendering. 

The effect of water on the dynamic mechanical behavior of a hydrogenated, sulfonated PP is displayed in Figure 7 for a quenched film of Sample HyPPSO3Na(20). The sample labeled dry had been stored in... 

Figure 9 Changes in the advancing( a) and reccding( 6 r) contact angles of water on the oxygen-plasma treated nylon 6 film with aging time. Rim D Mclt-piesscd and quenched film.

Independent of molecular wdght and sample, the cold-drawing of all melt-quenched films (amorphous preform) of P(3HB) (M = 0.6x 10 ), P(3HB-co-8%-3HV)... 

Fig. 11.23 a PL (fluorescence) spectra and b CPL (ot CPF, circularly polarized fluorescence) spectra of (/f)-Poly-10 cast films. The wavelength of excitation light for fluorescence was 380 nm. The inset shows photographs of the emitting film of the open form and the quenching film of the PSS of (7 )-Poly-10 (excitation wavelength A = 370 nm, 4 W, handheld lamp). Reprinted with permission from [20], Copyright 2010, Wiley... 

Figure 5.14 CPMAS/DD CNMR spectra [26] of (a) form I and (b) form II s-PS. The form II sample of (b) was obtained by absorption of dichloromethane into an amorphous, melt-quenched film of s-PS. SSB, spinning side-band.

Figure 3 shows the infrared spectra of the phenyl out-of-plane mode of sPS and sPPMS, before and after soaking in phenol solution. The peaks characteristic of the ttgg conformation at 572 cm i and 566 cm i for sPS and sPPMS are well-known to be very sensitive to the conformation. These peaks increased in intensity for both cast-crystaUized and melt-quenched films after soaking in phenol solution. This is direct evidence that the crystal with a ttgg conformation was induced by the presence of phenol. 

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