Ethylene-4 methyl pentene copolymer

Figure 4.5 The i C-NMR spectrum of an ethylene-4-methyl pentene copolymer.

Figure 4.6 C-NMR spectrum of ethylene-methyl-pentene-1 copolymer showing chemical shift assignments. Reproduced with permission from H.N. Cheng and M. Kakugo, Macromolecules, 1991,24,1724. 1991, ACS...

Poly(methyl pentene), unfilled Low-density Medium-density High-density Ultra high-molecular-weight Glass-fiber- reinforced, high-density Ethylene-vinyl acetate copolymer... 

Phenylbenzofuran (282) was used to protect polyphenylene ether resins against damage from UV radiation <87USP4665ii2>. As a nucleating agent, benzofuran-2-carboxylic acid (283) was found to improve the properties of an ethylene/4-methyl-l-pentene copolymer <84JAP(K)59197446). 

Linear low-density polyethylenes. LLDPEs are copolymers of ethylene with olefins, such as n-butene, n-octene and 4-methyl pentene-1, prepared using metal alkyl polymerization catalysts at low pressure and temperature. Copolymer content is adjusted to control the mechanical properties and degree of crystallinity. In general, they do not contain high proportions of the comonomers, and a typical copolymer with a 0.92 density will have 1-2% comonomer content. 

EPDM (55 parts)/ethylene 4-methyl-1-pentene copolymer (20 parts)/PP (25 parts)A.130 RI (0.2 parts) + divinylbenzene (0.3 parts) TSE at 230 "CAensile and film properties vs. blend made without ethylene-methylpentene copolymer Yonekura et al. 1988 (see also Otawa et al. 1988)... 

Figure 1 Polymer interpretation chart. PAI, polyamideimide PC, polycarbonate UP, unsaturated polyester PDAP, diarylate phtalate resin VC-VAc, vinyl chloride-vinyl acetate copolymer PVAc, polyvinyl acetate PVFM, polyvinyl formal PUR, polyurethane PA, polyamide PMA, methacrylate ester polymer EVA, ethylene-vinyl acetate copolymer PF, phenol resin EP, epoxide resin PS, polystyrene ABS, acrylonitrile-butadiene-styrene copolymer PPO, polyphenylene oxide P-SULFONE, poly-sulfone PA, polyamide UF, urea resin CN, nitrocellulose PVA, polyvinyl acetate MC, methyl cellulose MF, melamine resin PAN, polyacrylonitrile PVC, polyvinyl chloride PVF, polyvinyl fluoride CR, polychloroprene CHR, polyepichlorohydrin SI, polymethylsiloxane POM, polyoxy-methylene PTFE, polytetrafluoroethylene MOD-PP, modified PP EPT, ethylene-propylene terpolymer EPR, ethylene-propylene rubber PI, polyisoprene BR, butyl rubber PMP, poly(4-methyl pentene-1) PE, poly(ethylene) PB, poly(butene-l). (Adapted from Ref. 22, p. 50.)...

Particular studies of the IR spectra of polymers include isotactic poly(l-pentane), poly(4-methyl-l-pentene), and atactic poly(4-methyl-pentene) [18], chlorinated PE [19], aromatic polymers including styrene, terephthalic acid, isophthalic acid [20], PS [21, 22], styrene-glycidyl-p-isopropenylphenyl ether copolymers [23], styrene-isobutylene copolymers [24], vinyl chloride-vinyl acetate-vinyl fluoride terpolymers [25], vinyl chloride-vinyl acetate copolymers [26], styrene copolymers [27], ethylene-vinyl acetate copolymers, graft copolymers, and butadiene-styrene [28] and acrylonitrile-styrene copolymers [29]. 

In P-Tref/SEC cross-fractionation, copolymer chains are first fractionated according to comonomer composition into a series of fractions using P-Tref. Each fraction is then analyzed using SEC to obtain its MWD. P-Tref/SEC is a very powerful cross-fractionation technique because it provides information on the bivariate comonomer composition and MWD. Although the process is still time-consuming, the information obtained with P-Tref/SEC crossfractionation provides an almost complete map of chain microstructures. This cross-fractionation technique has been used for various ethylene/1-olefin copolymers (1-butene, 1-hexene, 1-octene, and l-pentene-4-methyl). 

Other common cross-fractionation techniques are SSF/A-Tref and SSF/ P-Tref [41,42]. In these techniques, polymers are first fractionated using SSF and the fractions are then further fractionated according to chain crystallizabilities using A-Tref or P-Tref. When P-Tref is used, further determination of comonomer content by C NMR or FTIR spectroscopy is required. Figures 19 and 20 show 3D and contour plots of bivariate distributions of molecular weight and comonomer composition obtained by SSF/P-Tref crossfractionation for an ethylene/l-pentene-4-methyl copolymer [42]. Comparing the contour plot with the equivalent contour plot of a LDPE sample (Fig. 21), one clearly notices significant differences between the bivariate distributions of these two samples. 

Copolymers of syndiotactic poly(propylene) behave in a similar manner.(64) Here the copolymers with ethylene, 1-pentene, 1-hexene and 4-methyl-1-pentene as co-units obey the same melting temperature-composition relation. On the other hand, the copolymer with 1-butene gives higher melting temperatures than the others. This result will also be discussed further in the next section. 

Figures 4.2 to 4.6 show NMR spectra of ethylene copolymers with propylene, butene-1, hexane-1, octane-1 and 4-methyl pentene-1. These spectra show chemical shift assignment of T values of the resonances of the copolymers. The molar composition of these copolymers could be determined with a relative precision at about 6% and pm value measurements at 10 ppm and 50 ppm.

De Footer and co-workers [19] applied C-NMR spectroscopy at sample temperatures of 130 "C to branching studies of copolymers ethylene with 1-10 mole% of propylene, butene-, hexene-1, octene-1 and 4 methyl pentene-1. C-NMR spectra were recorded with proton noise decoupling to remove unwanted scalar... 

The NMR spectroscopy has also been applied to the analysis of copolymers of ethylene with butane-1, hexane-1, octane-1 and 4-methyl pentene-1 [27]. Cheng [38] and Fisch and Dannenberg [39] have also discussed the application of C-NMR to the measurement of ethylene - butane-1 copolymers. They analysed copolymers containing up to 11% bound to propylene. 

NMR spectroscopy has also been used to elucidate the composition of butane -ethylene - propylene [41], ethylene - butene-1 [42] and 4-methyl pentene-1-pentene copolymer [42, 43]. 

Other ethylene copolymers that have been studied include those with vinyl alcohol [64], acrylates [65] tetrafluoroethylene [66], 4-methyl pentene [67, 68], propylene - vinyl chloride [69], ethylene vinyl cyclohexane [70] and ethylene - vinyl acetate [71]. 

The examination of rj t2 values for hundreds of different comonomers polymerized by different mechanisms (2) reveals that in the overwhelming majority of cases these r, r2 values are close to or less than 1 very few examples of ionic processes were found with rjr2>l (J69). For this reason the appearance of a significant number of cases with rir2>t can be regarded as characteristic of complex catalysis. The mentioned tendency is especially pronounced when the comonomers have alkyl groups of different size (ethylene—4-methylpentene-l, pro-pyIene-butene-1, propylene-styrene, propylene-4-methylpentene-l, pro-pylene-vinylcyclohexane). On the other hand, when the alkyl groups are of similar bulkiness (4-methylpentene-l-vinylcyclohexane, 4-methyl-pentene-l-3-methylbutene-l, vinylcyclohexane-styrene), the copolymers obtained are mainly random or have a tendency to alternation. 

In recent years new ethylene copolymers (LLDPE) arrived on the market with density in the 0.915-0.935 gcm interval. LLDPE are copolymers of ethylene and small amount of another a-olefin, such as 1-butene, 1-hexene, 4-methyl pentene or 1-oetene. New generation of super strength grade have been prepared, most recently using higher olefins comonomer. 

Other polymers with properties similar to those of picarin include a copolymer of norbornene and ethylene (NEC), which has a transmission of about 90% (for a 2 mm-thick sample) in the frequency range between 0.2 and 1.2THz [111], and poly(4-methyl pentene-1) (TPX Mitsui Chemicals). The latter is transparent at UV, visible and far-IR frequencies [112]. The chemical structures of the base units of these polymers are provided in Chart 2.13. 

Isomerization polymerizations can be associated with coordination catalyst systems, ionic catalyst systems, and free radical systems. The cationic isomerization polymerization of 4-methyl-1-pentene is of interest because the product can be viewed as an alternating copolymer of ethylene and isobutylene. This structure cannot be obtained by conventional... 

Linear low-density polyethylene (LLDPE)440-442 is a copolymer of ethylene and a terminal alkene with improved physical properties as compared to LDPE. The practically most important copolymer is made with propylene, but 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene are also employed.440 LLDPE is characterized by linear chains without long-chain branches. Short-chain branches result from the terminal alkene comonomer. Copolymer content and distribution as well as branch length introduced permit to control the properties of the copolymer formed. Improvement of certain physical properties (toughness, tensile strength, melt index, elongation characteristics) directly connected to the type of terminal alkene used can be achieved with copolymerization.442... 

Four olefins are used in industry to manufacture ethylene copolymers 1-butene, 1-hexene, 4-methyl-1-pentene. and 1-octene. Copolymers containing 1-butene account for approximately 40% of all LLDPE resins manufactured worldwide, 1-hexene copolymers for 35%, 1-octene copolymers for about 20%, and 4-mcthyl-l-pcntcnc copolymers for the rest. The type of o-olcliit exerts a significant influence oil tlie copolymer properties. 

Random ethylene copolymers with small amounts (4-10 wt-%) of 7-olefins, e.g. 1-butene, 1-hexene, 1-octene and 4-methyl- 1-pentene, are referred to as linear low-density polyethylene, which is a commercially relevant class of polyolefins. Such copolymers are prepared by essentially the same catalysts used for the synthesis of high-density polyethylene [241]. Small amounts of a-olefin units incorporated in an ethylene copolymer have the effect of producing side chains at points where the 7-olefin is inserted into the linear polyethylene backbone. Thus, the copolymerisation produces short alkyl branches, which disrupt the crystallinity of high-density polyethylene and lower the density of the polymer so that it simulates many of the properties of low-density polyethylene manufactured by high-pressure radical polymerisation of ethylene [448] (Figure 2.3). 

Isotactic poly(4-methyl-l -pentene) Ethylene/isotactic propylene block (compact) copolymers (polyallomers)... 

The most important monomers for the production of polyolefins, in terms of industrial capacity, are ethylene, propylene and butene, followed by isobutene and 4-methyl-1-pentene. Higher a-olefins, such as 1-hexene, and cyclic monomers, such as norbornene, are used together with the monomers mentioned above, to produce copolymer materials. Another monomer with wide application in the polymer industry is styrene. The main sources presently used and conceivably usable for olefin monomer production are petroleum (see also Chapters 1 and 3), natural gas (largely methane plus some ethane, etc.), coal (a composite of polymerized and cross-linked hydrocarbons containing many impurities), biomass (organic wastes from plants or animals), and vegetable oils (see Chapter 3). 

Isomerization from the secondary to the more stable tertiary carbonium ion precedes reaction with the next molecule of monomer. A 1,3 polymerization has therefore occurred. Similarly, 4-methyl-l-pentene gives a 1,4 polymer (probably involving two successive 1,2 hydride shifts) that has a structure corresponding to an ethylene-isobutylene copolymer (Reaction 25). 

Introduction of metallocenes in state-of-the-art technologies gives access to new copolymers of ethylene and 1-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene with narrow molecular mass distributions and uniform copolymer compositions. On this basis it is possible to synthesize polyolefins with well-balanced properties. These metallocene/methylalumoxane... 

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