Poly vinylidene chloride, 763 table

Comparison of Table 5.4 and 5.7 allows the prediction that aromatic oils will be plasticisers for natural rubber, that dibutyl phthalate will plasticise poly(methyl methacrylate), that tritolyl phosphate will plasticise nitrile rubbers, that dibenzyl ether will plasticise poly(vinylidene chloride) and that dimethyl phthalate will plasticise cellulose diacetate. These predictions are found to be correct. What is not predictable is that camphor should be an effective plasticiser for cellulose nitrate. It would seem that this crystalline material, which has to be dispersed into the polymer with the aid of liquids such as ethyl alcohol, is only compatible with the polymer because of some specific interaction between the carbonyl group present in the camphor with some group in the cellulose nitrate. 

The 1,1-disubstitution of chlorine atoms causes steric interactions in the polymer, as is evident from the heat of polymerization (see Table 1) (24). When corrected for the heat of fusion, it is significantly less than the theoretical value of —83.7 kJ/mol (—20 kcal/mol) for the process of converting a double bond to two single bonds. The steric strain apparendy is not important in the addition step, because VDC polymerizes easily. Nor is it sufficient to favor depolymerization the estimated ceiling temperature for poly(vinylidene chloride) (PVDC) is about 400°C. 

As Table III shows, where previously published values of CST are available, they are substantially equal to the values found in this study. However, the literature value assigned to Saran is the composite value for poly(vinyl chloride) (39) and poly(vinylidene chloride) (40). The literature value for silicone is the CST of poly(dimethylsiloxane) sorbed onto glass rather than that of cured poly (methyl hydrogen siloxane) which... 

Poly(vinylidene Chloride) Copolymer. Contact angles observed on poly(vinylidene chloride) copolymer surfaces prepared by solvent evaporation are given in Table IV, along with the values obtained on highly polished surfaces of compressed disks of the additive-free powdered polymer. Values of 9 exhibited by the various liquids on each type of... 

TABLE IV. Contact Angles of Various Liquids on Poly(vinylidene Chloride) Copolymer... 

Geometric factors, such as the symmetry of the backbone and the presence of double bonds on the main chain, affect Tg. Polymers that have symmetrical structure have lower Tg than those with asymmetric structures. This is illustrated by two pairs of polymers polypropylene vs. polyisobutylene and poly(vinyl chloride) vs. poly(vinylidene chloride) in Table 4.4. Given our discussion above on chain stiffness, one would have expected that additional groups near the backbone for the symmetrical polymer would enhance steric hindrance and consequently raise Tg. This, however, is not the case. This discrepancy is due to conformational requirements. The additional groups can only be accommodated in a conformation with a loose structure. The increased free volume results in a lower Tg. 

Typical examples of the mixed emulsion-spinning of polyvinyl chloride, polyethylene, poly-vinylidene chloride, and polyvinyl acetate, and some properties of the mixed fibers are shown in Table 4.26. The measurement of the fiber properties is carried out after hot-drawing in dry air at 180°C, heat treatment for 100 sec at 250°C, and acetalization for 40 min at 70°C without tension. The draw ratios shown in the table are the highest possible ratios under the given experimental conditions. In most cases, there is a maximum possible draw ratio at a certain mixing ratio. However, only the results of experiments at mixing ratios of 1 3 and 1 1 are shown in the table. 

Plasticizer studies were conducted in order to improve the foamability of the other monomeric constituents of the VDC-based copolymers. Table 4.5.2 shows the classes and formulations of the Scientific Polymer Products plasticizers used in this study. Also, water and V-methyl-2-pyrolidinone (NMP) were considered in the plasticizer studies. Studies of P(VDC-AN), poly(vinylidene chloride-co-vinyl chloride) (PVDC-VC), and poly(vinylidene chloride-co-acrylontirile-co methyl methacry-... 

Many isotactic forms of polymers or simple linear chains, such as polytetra-fluoroethylene and poly(vinylidene chloride), have helical conformations. The pitch of the helix is determined by the influence of the nonbonding short-range interactions between adjacent atoms on the polymer backbone. Helical structures are frequently observed and reflect the subtle effects of these interactions. The controlling factor is the enthalpy of the melt process and Table 5.1 summarizes values for some common polymer systems. 

In this section, I have demonstrated potential of FUV spectroscopy in the 120-300 nm region in the classification of commercial food wrap films (three types of polyethylene (PE), poly vinylidene chloride (PVDC), and polyvinyl chloride (PVC) see Table 5.4). Sato and I have measured FUV spectra in the 120-300 nm region of six types of commercial polymer wrap films [53]. FUV spectroscopy enables classification of polymer thin films in a straightforward manner by using raw spectral data. We also studied identification of three types of polyethylene PE films from different commercial companies. The FUV spectra of these PE films, which have very similar components and additives, are easily separated. The two types of PVDC films can also be identified. The present study has revealed that FUV spectroscopy is a very promising tool for the polymer film analysis. 

The infrared active vibrations of poly(vinylidene chloride) are known [see Krinun (I960) and Miyazawa and Ideguchi (1965)]. Table III. ... 

Experimental values of permeability of nitrogen at room temperature through various elastomers, semicrystalline, and amorphous polymers showed great variation depending on the polymer. Thus, silicone rubber showed the highest permeability of 10 cm /s-Pa, whereas poly(vinylidene chloride) showed the lowest of 4 x 10 cm /s-Pa. Table 4.11 provides rules of thumb on relative permeability and activation energy. 

Copolymerization. Vinyl chloride can be copolymerized with a variety of monomers. Vinyl acetate [9003-22-9], the most important commercial comonomer, is used to reduce crystallinity, which aids fusion and allows lower processing temperatures. Copolymers are used in flooring and coatings. This copolymer sometimes contains maleic acid or vinyl alcohol (hydrolyzed from the poly(vinyl acetate)) to improve the coating s adhesion to other materials, including metals. Copolymers with vinylidene chloride are used as barrier films and coatings. Copolymers of vinyl chloride with maleates or fumerates are used to raise heat deflection temperature. Copolymers of vinyl chloride with acrylic esters in latex form are used as film formers in paint, nonwoven fabric binders, adhesives, and coatings. Copolymers with olefins improve thermal stability and melt flow, but at some loss of heat-deflection temperature (100). Copolymerization parameters are listed in Table 5. 

Fig. 15. Oxygen permeability versus 1/specific free volume at 25 °C (30). 1. Polybutadiene 2. polyethylene (density 0.922) 3. polycarbonate 4. polystyrene 5. styrene-co acrylonitrile 6. polyethylene terephthalate) 7. acrylonitrile barrier polymer 8. poly(methyl methacrylate) 9. poly(vinyl chloride) 10. acrylonitrile barrier polymer 11. vinylidene chloride copolymer 12. polymethacrylonitrile and 13. polyacrylonitrile. See Table 1 for unit conversions.

The observations of critical swelling in polymer-monomer systems was demonstrated by Ceresa, who used this method to synthesize many block copolymers, for example, poly(methyl methacrylate) with acrylonitrile, styrene, vinylidene chloride, or vinyl acetate polyethylene with methyl methacrylate or styrene and cellulose acetate with acrylonitrile [114, 168, 170-172]. For the last system, the critical change in swelling rate occurred after 40 min at a monomer uptake of 15%. Below this point no polymerization occurred (see Table 5.23 [114]). 

Table 1. Second virial coefficient of poly(acrylonitrile-co-vinylidene chloride).

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