E-P copolymer

A polymer-bound hindered amine light stabilizer [P-HALS] has been synthesized by terminating the living anionic polymerization of isoprene with 4(2,3-epoxy pro-poxy)-1,2,2,6,6-pentamethylpiperidine followed by hydrogenation of the resulting polymer to E-P copolymer using Zeigler type catalyst [40] ... 

The photostabilizing efficiency of polymer-bound HALS in i-PP and E-P copolymers were studied and compared with commercial HALS (i.e., Tinuvin 770 and Chimassorb 944) by measuring the carbonyl index at 1720 cm. Plots of carbonyl index versus irradiation... 

Figure 3 Plot of carbonyl index versus irradiation time in E-P copolymer at 0.2 wt% concentration of stabilizers.

The vulcanization recipe wasi EPDM 100, stearic acid 1.0, zinc oxide 5 0, accelerator M 0.5, TMTD 1.5, HAF 50, sulfur 1.5 phr. Peroxide-curing of E-P copolymers was carried out with a modified procedure of (6) EPR 100, dicumyl peroxide 3, zinc oxide 3, TMTD 0.5, HAF 50, sulfur 0.2 phr, the mixture being masticated for 20 minutes at 0-50°C and cured at lb0°G. 

To circumvent any effect on tensile properties that might have concurred in the presence of the third monomer, hydroperoxide curing of E-P copolymer samples comparable in and... 

Random E/P copolymers consist of PP chains in which small amounts of ethylene (C2) are more or less randomly distributed. The C2 units act as defects for the regularity of chain configuration and reduce the overall crystallinity of the polymer. 

Fig. 1. Temperature dependence of G-values of n-butane and isobutane from y-irradiation of E-P copolymer (o) n-butane ( ) isobutane CHjSH (a) n-butane, (a) isobutane (CjHjIjN ( ) n-butane, ( ) isobutane...

Table 2. Melting temperatures T , melting enthalpies AH and crystallinity of E-P copolymers, heated at 200 °C and annealed for 5 min at different temperatures...

Table 3. The changes of melt enthalpy (AH ) and crystallinity in E-P copolymers in the solid state after polychromatic irradiation (>290nm) at 30 C...

Although it is reasonable to expect differences in degradation behaviour between random and heterophase copolymers, literature seldom defines clearly the nature of copolymers studied. Well characterized heterophase E-P copolymers, however, are of very recent origin. 

Kimura et al. [107] made a light resistant formulation of a block E-P copolymer by extruding it at 220 °C with Mg(OH)2, and 2-hydroxy-4-octoxybenzophenone. The injection molded product (at 800 kg cm pressure) shows fire retardation also due to MgO filler and the benzophenone derivative is an efficient UV absorber. 

The copper catalyzed degradation of E-P copolymer (3-40 mol% C2H4) is prevented [117] by azimidobenzene or phenothiazine or their derivatives and 0.1-5 wt.% [4,4 -thiobis(3-methyl-6-tert-butylphenol)] and iV-phenyl-p-naphthyl-amine. The later two compounds are powerful antioxidants and functions as follows ... 

The E-P copolymer (2.98 moI% C2H4) was stabilized [134] against heat find light degradation by incorporation in the copolymer matrix dialkyl thiodipro-pionate or 2-(2 -hydroxyphenyl)-2,4,4-trimethyldialkyl-5,6-dinonyl or alkylidene-... 

Observations on this system may not apply to other catalyst systems but the fact that abnormal addition of propene has been demonstrated in elastomeric E/P copolymers prepared under very different conditions makes it clear that, at the least, the values of and rj are approximations. It would be of interest to calculate (assuming, for example, that the ratio of the fractions of head-to-head and head-to-tail units equals the ratio of the corresponding rate coefficients) what differences from the true rj and T2 ratios would result from the occurrence of 5—10% of abnormal addition. 

One of the first mechanical thermoplastic IPNs was that prepared by Exxon Chemical and made by melt blending ethylene-propylene (E-P) copolymer or EPDM with polypropylene in the presence of a small amount of peroxide as cross-linking agent. Recently, Shell Chemical... 

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