Blends of chlorinated polyethylene

When two polymers interact or react with each other, they are likely to provide a compatible, even a miscible, blend. Epoxidized natural rubber (ENR) interacts with chloro-sulfonated polyethylene (Hypalon) and polyvinyl chloride (PVC) forming partially miscible and miscible blends, respectively, due to the reaction between chlorosulfonic acid group and chlorine with epoxy group of ENR. Chiu et al. have studied the blends of chlorinated polyethylene (CR) with ENR at blend ratios of 75 25, 50 50, and 25 75, as well as pure rubbers using sulfur (Sg), 2-mercapto-benzothiazole, and 2-benzothiazole disulfide as vulcanizing agents [32]. They have studied Mooney viscosity, scorch... 

Analogous behavior was observed by Oswald and co-workers (12) for blends of chlorinated polyethylene with a high chlorine content when the difference between the Tg s of the two components was greater than 30°C. In our case the values of ATg are about 45° (E13) and 34°C (E14) in regard to the homopolymer PVC. 

Fig. H. Plots of tan 8 against temperature for blends of chlorinated polyethylene (44 % Cl) with chlorinated polyethylene (66% Cl) 1 pure CPE (66% O) 2 87.0% 3 73.5% 4 50.0% 5 25.0% and 6 11.0% of CPE (66 % Cl) in CPE (44 % O) 7 pure CPE (44% Cl). The inset shows a plot of T against weight percent of the chlorinated polyethylene with the higher chlorine content, there is no marked deviation from linearity which is the expected result for systems with no specific interaction...

Fig. 15. DiiTerential thermal analysis traces of a blend of chlorinated polyethylene with poly(methyl methacrylate) obtained by heating at a rate of 10 °C/min. The blend was kept at the quoted temperatures for 10 min. and was quenched prior to scanning. The appearance of two T s after treatment at 190 C is indicative of phase separation at this temperature...

Fig. 18. A plot of the minimum of the cloud point curve against chlorine content for blends of chlorinated polyethylene with ethylene-vinyl acetate copolymers having A (40 % vinyl acetate), B (45 % vinyl acetate). It is seen that the higher concentrations of interacting groups, CHCl or C=0, give a larger temperature range of miscibility...

Simulation studies have also been carried out on blends of chlorinated polyethylene with poly(butyl acrylate). The results are shown in Fig. 30. It was found in this case (in a similar way to the previous example) that with the value of X obtained from heat of mixing studies at 70 °C on oligomers (—94 atm) and with the value of Qjj necessary to match the spinodal to the minimum of the cloud point (—0.235 atm/K.) the resulting spinodal was very flat bottomed and lay outside the cloud point curve, an impossible situation. To match the spinodal to the cloud point curve a much smaller value of Xj2 (and correspondingly Qij) must be chosen. This discrepancy could have resulted from differences between the low molecular weight materials used for heat... 

A plot of tan 5 versus temperature gives a strong indication of blend homogeneity when a single Tg is detected or inhomogeneity when two Tg s are detected. An example of this method in studying blends of ethylene-vinyl acetate copolymers (45 wt.- % Ac) with chlorinated polyethelene (52 wt.- % Cl) at a constant frequency of 11 Hz is shown in Fig. 10. Similar results obtained for blends of chlorinated polyethylene (44 wt.- % Cl) with chlorinated polyethylene (62 wt.- % Cl) are shown in Fig. 11. 

Figure 2.14 Miscibility map for blends of chlorinated polyethylene (CPE) and a-methyl styrene/acryloni-trile (MSAN) copolymer (reproduced (replotted) from reference Cowie,J.M.G.,Elexpuru,E.M. and McEwen,. y,J.Polym.Sci. Part B Polym.Phys.,( 99 ) 29, p. 407, with permission of John Wiley Sons, Inc.)...

Static quenching of PS fluorescence emission has been discovered in PS-PVME blends. Although such phenomenon is generally uncommon in pol3rmer mixtures, we have recently jjbserved similar quenching effects in poly(dimethylphenylene oxide)-PS mixtures and also in blends of chlorinated polyethylene and anthracene-labelled poly(methylmethacry-late). 

I 50/50 biends of SxMMA1 x/SyMMA1 y, a) at 25 °C, b) at 180°C one phase, O two phases. The solid curves have no theoretical background [52], Similar results have been found for 50/50 blends of chlorinated linear polyethylenes [52]. 

IV 50/50 blends of chlorinated linear polyethylenes at 70 °C O one phase, two phases. The dashed curves have no theoretical background [56], The result deviates from predictions of the theory in that respect that the miscibility region expands to form bulges. The same phenomenon was observed for 50/50 blends of chlorinated branched polyethylenes (with shrinking miscibility area in comparison to linear polyethylenes) [56] and chlorinated PVCs [52]. Thus, there are conflicting results on chlorinated linear polyethylenes and chlorinated PVCs. 

Chlorinated polyethylene was evaluated as a compatibiliser forpoly(vinyl chloride) composites containing 25% or 40% wood flour. The compositions also contained lubricants, a stabiliser and a processing aid. Following blending, the composites were characterised by rheology studies and measurements of melt strength. The addition of chlorinated polyethylene significantly enhanced the processability of... 

One example in this category is the case of one polymer in two stereoregular forms Other examples are of two polymers which are chemically very similar such as poly(methyl acrylate) with poly(vinyl acetate) A series of systems which have been studied in some detail are various mixtures of chlorine containing polymers. Blends of chlorinated PVC with PVC have been studied It has been suggested that at 65.2 % wt.- % chlorine they are miscible and at 67.5 wt.- % they are not. Chlorinated polyethylene with 45 wt.- % chlorine has also been found to be miscible with PVC In this case it was suggested that phase separation occurs on heating. 

Fig. 23. A part of the infra red spectra showing the carbonyl band absorption for (A) an ethylene-vinyl acetate copolymer and its blends with (B) 40 % and (Q 80% chlorinated polyethylene. The peak is shifted due to a specific interaction between the carbonyl and the methine hydrogen of chlorinated polyethylene. The shifted peaks are actually a combination of a shifted and an unshifted peak at different ratios...

Figure 3. Representative curves, obtained by T-m.d.s.c., of 50-50 wt% blends of chlorinat polyethylene with 36 wt% chlorine and a co-polyesteramide containing 40.3 mole% LA.

P. Bhagabati, T.K. Chaki, Compatibility study of chlorinated polyethylene/ethylene methacrylate copolymer blends using thermal, mechanical, and chemical analysis. J. Appl. Polym. Sci. 131, 40316 (2014)... 

Figure 12.1 shows the relationship between the composition of chlorinated polyethylene, CPE, and di-(2-ethylhexyl) phthalate, DOP, mixtures and glass transition temperature. Regression lines for both relationships are very close. This means that CPE behaves in a similar manner when tested in a simple mixture with DOP and in temaiy blend containing also PVC. Figure 12.2 shows a similar relationship for PVC which also behaves in a way similar to CPE. It can be noted that PVC relationship shows a cusp at about 30 wt% of DOP as typical of PVC behavior (see more on this in Section 11.44.4 and Figures 11.47 and 11.48). 

The melting behaviour of blends with chlorinated polyethylenes (and PVC) also depends on several factors. These systems often exhibit two melting endotherms when investigated by DSC and T j was taken to correspond to the high-tempera-ture endotherm For blends in which PCL had crystallised from a single amorphous phase the melting temperature (T j) varied with the CPE content [100]. 

Asymmetric double cantilever beam and peel test experiments were completed by Eastwood et al. (Eastwood and Dadmun, 2002) to evaluate the ability of multiblock or blocky distributed chlorinated polyethylenes (bCPEs) to strengthen the PVC/POE interface compared to that of randomly distributed chlorinated polyethylene (rCPE). Additionally, the dependence of molecular weight and chlorine content of the bCPE (composition) will be evaluated to ascertain the influence of these parameters on the compatibilization process. Chlorinated polyethylenes to compatibil-ize poly(vinyl chloride) (PVC) and polyolefin elastomer (POE) blends. A series of chlorinated polyethylenes that are blocky in nature (bCPEs) with varying composition (% chlorine), and molecular weight (melt index) were used for this experiment. 

Why were the miscibility boundaries of chlorinated polyethylene, CPE and CPE blends not parallel straight lines ... 

Figure 4.10 FTIR absorbance spectra recorded at room temperature of an ethylene-vinyl acetate (EVA) copolymer blended with chlorinated polyethylene (CPE) and poly(vinyl chloride) (PVC). A, pure EVA B, 40 60 and C, 80 20 wt% CPE-EVA, respectively D, pure EVA E, 40 60 and F, 80 20 wt% PVC-EVA, respectively. Reproduced from ref. 197, by permission of the publishers Butterworth Heinemann Ltd .

Zhang, Z., Chen, S., Zhang, J., Li, B., and Jin, X. (2010) Influence of chlorinated polyethylene on poly(vinyl chloride)/poly (a-methylstyrene-acrylonitrile) blends Mechanical properties, morphology and thermal properties. Polym. Test., 29, 995-1001. 

Addition of ethylene copolymers to polyethylenes has been used to improve toughness, impact resistance, and chemical resistance in films and other forms [19]. Blends of polyethylene with ethylene-vinyl acetate formed two continuous phases, which could then be stabilized by crosslinking [20]. Addition of chlorinated polyethylene to polyethylene is helpful in reducing flammability [18]. 

The effect of the amorphous component on the crystallization ability of the crystallizable polymer has been examined for some miscible blends. An improvement of poly( -caprolactone) (PCL) crystallization has been observed in blends with chlorinated polyethylene (CPE) [20], while for poly(ethylene oxide)/poly(ethyl methacrylate) (PEO/PEMA) [21], PCL/SAN [22], and poly(butylene therephthalate)/polyarylate (PBT/ PAr) [23] blends, the crystallization ability is markedly reduced. 

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