Poly olefin Blends

A compatible blend of an olefin polymer material and an engineering thermoplastic is prepared by a process comprising (42)  

Making an oxidized olefin polymer material that contains carboxylic acid groups, 

Extruding a mixture of the oxidized olefin polymer material with an engineering thermoplastic, and optionally with additional virgin poly(olefin). 

Examples for engineering thermoplastic materials are poly(amide)s (PA)s, PCs, poly(imide)s, and poly(ester)s. The oxidation of the poly(olefin) can be achieved by the treatment with an organic peroxide initiator, such as tert-hutyl peroctoate (Lupersol PMS). 

Functionalized poly (propylene) (PP) by radical melt grafting with monomethyl itaconate or dimethyl itaconate is a compatibilizer in poly(propylene) (PP)/poly(ethylene terephthalate) (PET) blends. Blends with compositions 15/85 and 30/70 by weight of PP and PET, prepared in a single screw extruder, revealed a very fine and uniform dispersion of the PP phase compared to the respective non-compat-ibilized blends. 

---

Fig. 23. The relative surface tension difference -Ay/y(T) between components of six poly-olefinic blends grouped in three microstructurally identical pairs Xj/x2 (x1>x2) 66/52 (Q, ), 86/75 (A, ) and 75/66 (V, Y). Open and solid symbols correspond to blends with deu-terated more (x,) and less (x2) branched components, respectively. Large and small symbols correspond to previously determined whole segregation isotherms and singular surface excess data, respectively [16,120,145]. y(T) is given by Eq. (45) for polyethylene. Solid lines denote average values for each blend at Tref=100 °C (thick bar)...

Lame lias of crystalline phase of the surface layer of poly olefin blends studied are thicker than present in the surface layer of their components, what suggests co crystallization of ethylene monomer unit from EPDM. Linear LDPE facilitates the phenomenon, especially when takes place in amorphous elastomer matrix. Branched plastomer re crystallizes to the same lamellar thickness, no matter the structure of elastomer matrix. 

Poly(urethane)/poly(olefin) blend compositions are compatibi-lized using a zinc ionomer, based upon an ethylene/methacrylic acid/alkyl acrylate polymer, or a maleic anhydride-grafted ethylene oxide poly (olefin) elastomer (45). 

PPE modified with an epoxy-compound blended with PPE, PEST and hydrogenated poly- -olefin for processability and impact resistance Hasson Yates, 1993... 

PPAs are typically low in ductility as reflected by generally low values for elongation at break and the lack of significant extensibility in tensile testing. The ductility and rigidity can be improved by blending with poly(olefine)s. 

Mixtures of PPE and PS, or styrene-butadiene-styrene block copolymers have been extruded with maleic anhydride of fumaric acid to obtain compatibi-lized blends [42], In the same way, PPE with pendant glycidyl groups can be co-extruded with a poly(olefin) having anhydride groups [28], PPE can be grafted onto poly(ethylene) by melt kneading both modified polymers in the presence of a binder such as phenylenedi-amine. Both polymers are modified with maleic anhydride. The grafting takes place in situ. Amines may enhance the improvement of certain physical properties when used in combination with various compati-bilizers [29]. 

In general, the two polymer phases are incompatible. For this reason, a compatibilizer must be added to the blends in order to achieve good dispersing and mutual anchoring of the two polymer phases. Suitable compatibilizers are carboxylated or anhydride grafted poly(olefin)s. Such compatibilizers are generally commercially available, e.g.. Polybond , Exxelor , Hostamont , Admer , Orevac , Epolene , and Hostaprime [13]. 

Catbon-fiber-based Epoxy, polyfether keytones), poly(imide), poly(sulfone), i iopacifiers (BaS04, BaCl2, Ti02) blended into poly(olefins), poly(urethanes), silicones... 

Synthetic oils have been classified by ASTM into synthetic hydrocarbons, organic esters, others, and blends. Synthetic oils may contain the following compounds diaLkylben2enes, poly(a-olefins) polyisobutylene, cycloaUphatics, dibasic acid esters, polyol esters, phosphate esters, siUcate esters, polyglycols, polyphenyl ethers, siUcones, chlorofluorocarbon polymers, and perfluoroalkyl polyethers. 

Terpolymer blends containing poly(tetrafluoroethylene-co-perfluoro-a-olefins) and platinum nanoparticles imbedded in Nation 1100 fluoropolymer resin were previously prepared by the authors (1) and used as electrodes in fuel cells. 

As reported by Diehl et al. [58], interpolymers are also compatible with a broader range of polymers, including styrene block copolymers [59], poly(vinyl chloride) (PVC)-based polymers [60], poly(phenylene ethers) [61] and olefinic polymers such as ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer and chlorinated polyethylene. Owing to their unique molecular structure, specific ESI have been demonstrated as effective blend compatibilizers for polystyrene-polyethylene blends [62,63]. The development of the miscibility/ compatibility behavior of ESI-ESI blends differing in styrene content will be highlighted below. 

The largest volume of grease in use is made from petroleum products produced from naphthenic, paraffinic, blended, hydrocracked, hydrogenated, and solvent-refined stocks. In addition to petroleum oils, other lubricating fluids, such as esters, diesters, silicones, polyethers, and synthetic hydrocarbons, are also used. Of the synthetic fluids used in grease manufacture, the most common type is poly(alpha)olefin (PAO). 

The choice of date range is arbitrary. The number of journal articles for each year was obtained from a search of electronic version of English-based polymer and polymer-related journals using the keywords polyolefin and blends. Within polyolefin keyword, the subkeywords used in the search were polyethylene (PE, LLDPE, LDPE, HDPE, UHMWPE, PE, etc.), polypropylene (PP, iPP, sPP, aPP, etc.), polybutene-1, poly-4-methylpentene-l, ethylene-diene monomer, ethylene-propylene-diene terpolymer, ethylene propylene rubber, thermoplastic olefins, natural rubber (NR), polybutadiene, polyisobutylene (PIB), polyisoprene, and polyolefin elastomer. For the polyolefin blends patent search, polymer indexing codes and manual codes were used to search for the patents in Derwent World Patent Index based on the above keywords listed in the search strategy. 

Pickton[73] reported impact modified nylon blends of poly(2-methyl pentamethylene terephthalamide) and an ionomer such as a partially neutralized copolymer of -olefin and, -ethylenically unsaturated carboxylic acid as minor component. Melt blending of poly(2-methyl pentamethylene terephthalamide) and 1 wt% Du Pont Surlyn 8527 at 290 °C gave tensile modulus 68.4 g/d, tensile strength 7.4 g/d, and elongation at break 18.2%. 

From the chemical point of view, POs are simple materials composed of C and H. However, the configuration diversity of even the simplest polymethylene results in a spectrum of properties. The situation becomes more complex for polymers of the general formula (C H2 )dp where n>3 and the degree of polymerization, DP, is large. The next level of complexity is encountered with blends and copolymers, e.g., poly(ethylene-co-n-olefin) or poly(propylene-co-n-olefin). However, today the ultimate challenge for characterization is found in POs obtained during multi-catalyst/multi-reactor/multi-monomer polymerization processes. 

During the years 1992-1998, numerous publications emerged from Prof. Graessley s laboratory. The model PEs with different stmctures (see Fig. 18.10) were commercial (e.g., HDPE or PP) or from laboratory (e.g., hydrogenation/deuteration of diolefins, anionic reaction for PIB, Z-N catalysis using a V-based catalyst in Cg for poly (ethylene-co-a-olefin) or later a metallocene catalyst. The thermodynamic properties of numerous PO blends were extracted from the pressuie-volume-temperature (PVT) data (Walsh et al. 1992 Krishnamoorti et al. 1996) or from SANS results (Krishnamoorti et al. 1994, 1995 Graessley et al. 1994, 1995 Reichart et al. 1997 Alamo et al. 1997). 

Polypropylene, 55-90 wt% PP, was blended with poly (1-butene), PB, as a dispersed phase and optionally with up to 10 wt% of low-MW poly(a-olefin-co-ethylene) plastomer compatibilizer. The blends were useful for manufacturing fibers and nonwovens, with good hand and tensile strength ... 

Polyisobutylene of low molecular weight was synthesized by a Wurtz type reaction from l,4-dibromo-2,2,3,3 tetramethylbutane. Polyacrylates were obtained from alternating copolymerization of symmetric internal olefins or ethylene with maleic anhydride followed by quantitative esterification. Poly(vinyl halides) were prepared from cis-1,4-polybutadiene by chlorination (H-H PVC) or bromin-ation (H-H PrBr). The polymers were characterized and their chemical, thermal, degradation solution, melt and blending behavior was studied. 

---