Blends with Polyphenylene

A recent patent has reported partial miscibility of polyphenylenes 

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Blends of PET/HDPE have been treated previously in the literature [157, 158]. These are immiscible, but the addition of compatibilizers improves the mechanical properties of the blend, such as styrene-ethylene/butylene-styrene (SEBS) and ethylene propylene diene monomer (EPDM) [157], MAH [158], Poly(ethylene-stat-glycidyl metha-crylate)-graft-poly(acrilonitrile-stat-styrene) (EGMA), poly (ethylene acrylic acid), and maleated copolymers of SEBS, HDPE, ethylene-propylene copolymer (EP). The addition of compatibilizers modifies the rheological properties of blends of PET with HDPE, in such a way that increases in viscosity are observed as the component interactions augment. Changes in crystallization of PET were evaluated in blends with Polyphenylene sulfide (PPS), PMMA, HDPE aromatic polyamides, and copolyesters [159]. 

Ultem PEI/PPO PEI blends with polyphenylene ether GE Plastics... 

Oligomeric aromatic phosphates have been patented and commercially used as flame-retardant additives mainly for impact-resistant polystyrene blends with polyphenylene oxide and polycarbonate blends with acrylonitrile-butadiene-styrene (ABS) copolymers (130,131). They have also been shown useful in thermoplastic polyesters (92). The principal commercial examples are based on phenol and resorcinol (Akzo-Nobel s Fyrolflex RDP) or phenol and bisphenol A (Akzo-Nobel s Fyrolflex BDP or Albemarle s Ncendx P-30). Although these have the diphosphate as their principal ingredient, they also contain higher oligomers. 

S. M. Duff, An investigation into the crystallization mechanisms of semi-crystalline polymer blends Syndiotacticpolystyrene blended with polyphenylene ether, in M.Sc. Thesis. University of Limerick Limerick (1998). 

In polymers such as polystyrene that do not readily undergo charring, phosphoms-based flame retardants tend to be less effective, and such polymers are often flame retarded by antimony—halogen combinations (see Styrene). However, even in such noncharring polymers, phosphoms additives exhibit some activity that suggests at least one other mode of action. Phosphoms compounds may produce a barrier layer of polyphosphoric acid on the burning polymer (4,5). Phosphoms-based flame retardants are more effective in styrenic polymers blended with a char-forming polymer such as polyphenylene oxide or polycarbonate. 

Common conductive polymers are poly acetylene, polyphenylene, poly-(phenylene sulfide), polypyrrole, and polyvinylcarba2ole (123) (see Electrically conductive polymers). A static-dissipative polymer based on a polyether copolymer has been aimounced (124). In general, electroconductive polymers have proven to be expensive and difficult to process. In most cases they are blended with another polymer to improve the processibiUty. Conductive polymers have met with limited commercial success. 

PESA can be blended with various thermoplastics to alter or enhance their basic characteristics. Depending on the nature of thermoplastic, whether it is compatible with the polyamide block or with the soft ether or ester segments, the product is hard, nontacky or sticky, soft, and flexible. A small amount of PESA can be blended to engineering thermoplastics, e.g., polyethylene terepthalate (PET), polybutylene terepthalate (PBT), polypropylene oxide (PPO), polyphenylene sulfide (PPS), or poly-ether amide (PEI) for impact modification of the thermoplastic, whereas small amount of thermoplastic, e.g., nylon or PBT, can increase the hardness and flex modulus of PESA or PEE A [247]. 

Polyphenylene Oxide Blends with Impact Modifiers... 

Commercial examples are notably PVC-ABS blends and the blends of polyphenylene oxide with polystyrene. In the case of PPO-PS blends, it has been shown that the good char forming ability of the PPO greatly helps flame... 

Polyphenylene oxide (PPO) or Polyphenylene ether (PPE) is an amorphous polymer with a softening temperature of about 210 °C. To improve its processability it is mostly blended with PS (modified PPE, e.g. Noryl ), which is at the cost of its heat distortion temperature. The properties are excellent the applications are mainly in fine-mechanical construction, in automotive parts, in household equipment etc. 

Polymer blends can be subdivided into two kinds those of compatible and those of incompatible polymers. Real compatibility is an exception (see 9.1) an example is PS with PPE (polyphenylene ether, also called PPO, polyphenylene oxide). These two polymers can be blended with each other on such a small scale that it really looks like molecular miscibility. This blend shows, therefore, only one single glass transition. 

Polystyrene is one of the most widely used thermoplastic materials ranking behind polyolefins and PVC. Owing to their special property profile, styrene polymers are placed between commodity and speciality polymers. Since its commercial introduction in the 1930s until the present day, polystyrene has been subjected to numerous improvements. The main development directions were aimed at copolymerization of styrene with polar comonomers such as acrylonitrile, (meth)acrylates or maleic anhydride, at impact modification with different rubbers or styrene-butadiene block copolymers and at blending with other polymers such as polyphenylene ether (PPE) or polyolefins. 

Enhanced property demands in the packaging sector and also in the electric/ electronic and automotive sectors require improved product properties. Homogeneously miscible blends with, e.g., polyphenylene ether (PPE) combine the excellent processability of the amorphous polystyrene with the thermal stabilty of its blend partners. 

SBS with Polyphenylene ether (PPE) Evolution of PPE blends with SBS-type block copolymers is summarized in Table 1.23. SBS or its derivatives have been frequently used to stabilize the morphology in the newer, more complex blends. In Table 1.24 examples of this type of system are presented. 

Blends of polyphenylene ether (PPE, also known as PPO ) with HIPS are, by far, the most successful of all the commercial blends. Currently, more than 100 kton/y of PPE/HIPS blends are produced in the USA [Levy, 1991] almost exclusively by General Electric company, which originally introduced this blend commercially in 1964 under the trade name, Noryl . There are now other producers of this blend in Europe and Japan. 

Nonolefinic thermoplastic polymers that in principle may be blended with polyolefins include polyamides (nylons) such as polyamide 6, polyamide 66, polyphenylene sulfide (PPS), polyphenylene ether (PPF), and polyphenylene oxide (PPO) polyesters such as polyethylene terephthalate (PET), polybutylene terephtha-late (PBT), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PTT), polycarbonates, polyethers, and polyurethanes vinyl polymers such as polystyrene (PS), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA), and ethylene... 

Modification of Engineering Resins Specific interaction of the phosphonium ionomer from Exxpro elastomer with selected engineering resins such as Polycarbonates(PC), Polyesters(PET), Polyacrylates(PAE), Polyamides(PA), Polyphenylene Oxide(PPO), and Acetals(PAc) can be utilized to compatibilize, impact modify or nucleate the above resin in blends with similar polymers. Typical examples are ... 

D. F. Aycock and S.-P. Ting. Functionalized polyphenylene ethers and blends with polyamides. US Patent 5 069 818, assigned to General Electric Company (Selkirk, NY), December 3,1991. 

Blends containing PA and an anhydride-modified polyphenylene sulfide have been prepared by Kadoi et al. (1996). For example, PPS was extruded with either maleic anhydride, itaconic anhydride, or succinic anhydride to form a PPS shown to have carbonyl incorporation by FTIR after selective solvent extraction to remove unreacted anhydride. Blends of modified PPS and PA-66 were extruded at 290-310 °C and molded to provide test parts with improved properties compared to blends with unmodified PPS. 

Polymer blends were developed alongside the emerging polymers. Once nitrocellulose (NC) was invented, it was mixed with NR. Blends of NC with NR were patented in 1865 - 3 years before the commercialization of NC. The first compatibilization of polyvinylchloride (PVC) by blending with poly vinylacetate (PVAc) and their copolymers dates from 1928. PVC was commercialized in 1931, while its blends with nitrile rubber (NBR) were patented in 1936 - 2 years after the NBR patent was issued. The modem era of polymer blending began in 1960, after Alan Hay discovered the oxidative polymerization of 2,4-xylenols that led to polyphenylene ether (PPE). Its blends with styrenics, Noryl , were commercialized in 1965. 

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