Propylene-hexene copolymers blends

As discussed earlier, ethylene propylene rubber (EPR or EPM) has been blended with PP and PE to improve the impact strength and to render the materials softer. Recently, metallocene catalysts or postmetallocene catalysts provide new pathways to generate elastic copolymers that can replace EPR. These pathways possess cheaper manufacturing cost and generate new materials with better compatibility to PP or PE. Such new materials included ethylene-propylene random copolymers with dominant ethylene component (33-34) or propylene-dominant component (35 1), propylene-ethylene block copolymer (42), ethylene-octene copolymer (43), poly(propylene-co-ethylene) (44), ethylene-hexene copolymer (45), ethylene-butene copolymer (46), low isotactic PP (47), and stereoblock PP (48). These materials are generally compatible with PP or PE, thus can be used to tailor the toughness (or the softness) of... 

Fig. 39 Effect of comonomer type on cocrystallization at a cooling rate of 0.1 °C/min for blends with the same comonomer type. BPED blend of ethylene/1-dodecene copolymers, BPEO blend of ethylene/l-octene copolymers BPEH blend of ethylene/1-hexene copolymers, BPEP blend of ethjdene/propylene copolymers [67]...

The first results on 2D-LC for polyolefins were published by Ginsburg et al. [167, 177] and Roy et al. [178]. Roy et al. [178] applied a separation system that was previously described by Macko et al. [158, 159,162]. This system was applied to the separation of ethylene/1-octene copolymers regarding chemical composition and molar mass. Ginzburg et al. [177] used an instrument that has recently been developed and commercialized by PolymerChar (Valencia, Spain). They used the on-line coupling of gradient HPLC and SEC to separate blends of PP stereoisomers, ethylene/propylene mbbers, ethylene/norbomene copolymers and ethylene/1-hexene copolymers, all at an operating temperature of 160°C using a stationary phase of Hypercarb and a mobile phase of 1-decanol-TCB. 

Copolymers of propylene and hexene with MA, as shown in Table A.3, are also useful for preparing many products. Thermosetting resins prepared from the 1-hexene copolymer and epoxy resins may be fabricated into laminates with high heat distortion, good solvent resistance, and other attractive properties. Wood composites made with the same blend of alternating copolymer and epoxy resins are also potentially highly useful wood-plas-tics. Propylene-MA copolymers show great utility to prepare blends and laminates from polyolefin-nylon combinations. 

Reichart et al. (1998) studied blends of metallocene statistical copolymers of C2 with a range of propylene, 1-butene, 1-hexene, or 1-octene content, i.e., C2+3, C2+4, C2+6, and C2+8 (My,/M- 2). As expected, the new data scattered less than those for the Z-N copolymers, confirming the validity of the earlier observations. Thus, the interaction parameters obeyed Hildebrand s assumption as being controlled by... 

In our recent work [67], we investigated the effect of comonomer type on CO crystallization using a series of ethylene/1-olefin copolymers with four comonomer types propylene, 1-hexene, 1-octene, and 1-dodecene. Four blends, one for each copolymer type, were prepared such that they crystallized at the same temperature range and had similar ATq to ehminate the effect of similarity of chain crystalHzabihties. The Crystaf results of these blends indicated that the comonomer type of the parent samples did not appreciably influence their cocrystalHzation behavior, as illustrated in Fig. 39. 

Blends of iPP with random propylene-co-ethylene copolymers have been reported to be miscible and co-crystallizable [62]. In recent years several new copolymers of propylene (PP) with higher a-olefins have been synthesized due to the introduction of new metallocene catalysts. Propylene/1-hexene and propylene/1-octene copolymers have been reported to show thermodynamic properties, storage modulus, and density that decrease in a linear pattern with increasing comonomer content [63, 64]. Blending of copolymers offers the opportunity of designing innovative materials whose properties can be suitably modulated by varying both... 

From here on out, I will use the terms polyolefin or TPO to mean a thermoplastic polyolefin that is a blend (mechanical or so-called reactive types) of a plastic phase, primarily polypropylene, and an amorphous or elastomeric phase, consisting of truly ethylene-propylene copolymers or copolymers of ethylene with other a-olefins, such as butene or hexene. Considerations that must be addressed from both a commercial or practical point of view, as well as a theoretical or scientific point of view follow. 

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