Nylon blends with polypropylene

Polymer Blends. Commercial blends of nylon with other polymers have also been produced in order to obtain a balance of the properties of the two materials or to reduce moisture uptake. Blends of nylon-6,6 with poly(phenylene oxide) have been most successflil, but blends of nylon-6,6 and nylon-6 with polypropylene have also been introduced. 

Santrach [1] observed that HDT values were dependent on the amount and types of film former and lubricant. Fiber glass that has been sized for polyamide gives HDT values of about 240-252°C for nylon 6,6 levels above 50% in the polymer phase of compatibilized blends with polypropylene. However, in polypropylene type fiber glass, the HDT is only about 150-155°C. These observations are consistent with Santrach s comments about the addition of glass fibers to crystalline resins giving... 

Modification ofP/astics. Many plastics, such as PVC, ABS, polypropylene, and nylon, ate blended with nitnle mbber to improve flexibiHty, toughness, or appearance. An oil-resistant thermoplastic elastomer has been prepared by blending nitnle mbber and polypropylene (24). 

One of the earliest references on compatibilizing a nylon-6-polypropylene blend using maleic anhydride grafted PP (PP-g-MAH) was the work of Ide and Hase-gawa published in 1974 [35]. In their study, the formation of a graft copolymer was confirmed by DSC after solvent extraction of the PP component. Blends with PP-g-MAH... 

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]. 

Lu, B. Chung, T.C. New maleic anhydride modified polypropylene copolymers with block structure synthesis and application in PP/nylon blends. Macromolecules 1999, 32, 2525. 

Examples of such compatibilized systems that have been studied include EPDM/PMMA blends compatibilized with EPDM- -MMA, polypropylene/polyethylene blends with EPM or EPDM, polystyrene/nylon-6 blends with polystyrene/nylon-6 block copolymer, and poly(styrene-co-acrylonitrile)/poly(styrene-co-butadiene) blends with butadiene rubber/PMMA block copolymer. 

In 1970, an acid-dyeable polypropylene fiber was described [158]. It was claimed that this fiber could be dyed like nylon and could produce one-batch union shades in blends with cotton and acrylics. The dye site in this fiber was present as a microfilament dispersed within the polypropylene. These microfibers extended to the surface of the fiber and water was readily absorbed in order that acid dyes could penetrate at a reasonable rate to react with the basic dye sites. Acid-dyeable polypropylene fiber products have been available from Phillips [159] and, from Polyolefin Fibres Engineering (PFE) Ltd. [160]. PFE has also introduced a bicomponent fiber readily dyeable with disperse dyestuffs [161]. 

The most common polymers used for instrument panel stmctnres are acrylonitrile-butadiene-styrene (ABS), acrylonitrile-butadiene-styrene blended with polycarbonate (ABS/PC), polycarbonate (PC), poly(phenylene oxide) blended with nylon (PPO/nylon), poly(phenylene oxide) blended with styrene (PPO/styrene), polypropylene (PP), and styrene-maleic anhydride copolymer (SMA) [3]. The percentage of each of these polymers typically used in year 2000 models is shown below in Table 17.3 [3], All of these materials by themselves... 

Several approaches to compatibilizing PPE blends with commercial polyolefins (polypropylene, etc.) have been reported in the literature (Lee 1990 Kirkpatrick et al. 1989). Simultaneous compatibilization and impact modification of PPE/polypropylene blends was achieved by choosing selected types of styrene-ethylene/butylene-styrene block copolymers and PPE resin of low molecular weight (Akkapeddi and VanBuskirk 1992). A family of PPE/polypropylene alloys were commercially launched by G.E. in 2001, under the Noryl PPX trade name, and these are now sold by Sabic. Typical properties of a commercial PPE/PP blend are shown in Table 19.32. These PPE/PP blends are claimed to offer a balance of cost and performance between the TPOs and other higher-cost engineering thermoplastics such as nylons, modified PET, and PBT resins. Basically, the PPE/PP blends offer a balance of key properties stiffness, toughness, chemical, and heat resistance. 

The decrease is large when nylon is blended with PP and smaller when PP is blended with nylon. Comparing the composite properties, the long fiber polypropylene compounds can easily double the flexural modulus and Izod impact strengths over the corresponding short fiber polypropylene compounds... 

Dagli S.S., Xanthos M. and Biesenberger J. A. (1992), Blends of Nylon 6 and Polypropylene with Potential Applications in Recycling, Effects of Reactive Extrusion Variables on Blend Characteristics , American Chemical Society Symposium, Vol. 513. 241-257. 

Polymer alloys are commercial polymer blends with improvanent in property balance with the use of compatibilizers. Texas A M University [1] has patented a com-patibilizer that can result in a product with high impact resistance as well as scratch resistance. The blend is composed of HIPS or polypropylene (PP) and a compati-bilizer made of a triblock copolymer of styrene-ethylene-propylene. Udipi [2] discovered that polymer blends composed of PC, a copolyester of PETG, and nitrile rubber exhibit a superior balance of properties. Reactive compatibilization of PC/ SAN blends at various AN compositions were conducted by Wildes et al. [3] using a SAN-amine compatibilizer. PC and SAN were found to be miscible over a range of AN composition by Mendelson [5]. Nylon/ABS blends can be compatibilized by use of SAN-maleic acid (Lavengood et al. [6]). Styrene-GMA copolymers can be used as compatibilizers for PS/PA, PS/PBT, PS/PET, and PPO/PBT blends. 

Mechanical testing (strain-stress, tensile strength, elongation at break, elastic modulus, melt flow, viscoelastic properties, etc), have frequently been used in the study of the photodegradation of polyethylene [711, 1656, 1704, 1750, 1957, 2124, 2128], polypropylene [1750, 1899, 1903], poly(styrene) [748], poly(styrene-co-carbon monoxide) [1429], poly(styrene-co-acrylonitrile) [747], EPDM [896], poly(vinyl chloride) [806,1137,1138,1232,1748,1938], impact modified poly(vinyl chloride) [761, 764,1232], nylon 6 [672, 726, 727, 1395,1396,2300,2305], polyethylene blends with nylon 6 [506], and polyurethanes and its blends with poly(vinyl chloride), poly(vinyl alcohol), poly(vinyl acetate) and poly(vinyl chloride-co-vinyl acetate) [652]. 

Many of the polymer blends containing crystalline polymers involve crystalline polyolefins (e.g., polyethylene, polypropylene) and these blends will be discussed in Section 4.5. Additionally, crystalline engineering polymer blends, such as nylon 6,6, poly(butylene terephthalate), poly(aryl ether ketones), and poly(ethylene terephthalate), are blended with other engineering polymers (either amorphous or crystaUine) and these will also be discussed separately (see Section 4.6). Blends of the crystaUine engineering polymers with non-engineering polymers wiU be discussed in this section. AdditionaUy, crystaUine polyolefin blends with non-olefin polymers wiU be covered in this section. 

Poly[imino(l-oxohexamethylene)] Nylon 6 70/30 blend with 10% polypropylene with maleic anhydride... 

The two polymers are blended in an extruder and, due to this reaction, there is some sort of freezing of the microphases, thus giving higher shength. Another interesting example that has been reported in the literature is the compatibiliza-tion of polypropylene with nylon 6. The latter is a polyamide that has a carboxylic acid and an amine group at chain ends in another words, it is a telechelic. We then prepare a copolymer of polypropylene with 3% maleic anhydride. The melt extmsion of these polymers would lead to a blend with frozen matrices, as shown in Figure 2.4. 

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