Comparison of carboxylated and maleated polypropylene as reactive compatibilizers in polypropylene/polyamide-6,6 blends

Abstract

Using reactive extrusion, polypropylene is functionalized with maleic anhydride and compared on an equimolar basis to polypropylene that is functionalized with an asymmetric, carboxylic acid containing peroxide. The grafting efficiency for the asymmetric peroxide is double that obtained for the maleic anhydride system. Moreover, the asymmetric peroxide yields a functionalized material with minimal molecular weight degradation and desirable mechanical properties, relative to maleic anhydride‐grafted polypropylene. In compatibilized blends of polypropylene and nylon 6,6, the polypropylene that was functionalized with the asymmetric peroxide is found to be an improved compatibilizer compared to that of maleic anhydride‐grafted polypropylene. The differences in mechanical properties of the two different functionalized polypropylene materials and their respective blends are rationalized on the basis of the grafting efficiency, molecular weight degradation during reactive extrusion, and effect of free functional species on the ability to form graft copolymers in compatibilized blends. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2398–2407, 2001

Measures of adult general performance tests: The Berg Balance Scale, Dynamic Gait Index (DGI), Gait Velocity, Physical Performance Test (PPT), Timed Chair Stand Test, Timed Up and Go, and Tinetti Performance-Oriented Mobility Assessment (POMA)

“…This is not surprising, given that the alkoxy radical arising from it can either abstract a hydrogen from the polyethylene or generate by β scission a methyl radical that would react similarly. This observation is in agreement with those of Moore,12, 13 who identified the influence of the alkylperoxy moiety only when the alkyl radical, liberated in the β‐scission of the t ‐alkoxy radical, was an ethyl radical.…”

“…Free‐radical chemical modifications of polyolefins have been mainly realized by decomposition of a radical initiator in the presence of unsaturated compounds 1–11. To our knowledge, only the articles by Moore et al12, 13 have described the functionalization of polyolefins, polypropylene in this case, carried out by thermal decomposition of peroxyesters in the absence of any additive. Acid and ester functions were introduced onto polypropylene; one of functionalization mechanisms, invoked in the current study, was the combination of the macroradical, formed in the hydrogen abstraction from the polymer by one of the radicals produced in the decomposition of the perester, with the counterradical of this latter.…”

Properties of Styrene–Maleic Anhydride Copolymer Compatibilized Polyamide 66/Poly (Phenylene Ether) Blends: Effect of Maleic Anhydride Concentration and Copolymer Content

“…Phase separation leads to the formation of weak interfaces and cause high stress concentrations locally when under load. In order to control the phase separation, various compatibilization methods are applied, such as the addition of low-molecular-weight organic molecules [10][11][12][13], inorganic nanoparticles [14][15][16][17], Janus-type hybrid materials [18][19][20][21], and copolymers with functional moieties [22][23][24][25][26].…”

Properties of Styrene-Maleic Anhydride Copolymer Compatibilized Polyamide 66/Poly (Phenylene Ether) Blends: Effect of Blend Ratio and Compatibilizer Content

“…Since almost all polymer blend combinations reveal immiscible morphology due to macrophase separation, the mechanical properties of the materials deteriorate [ 4 , 5 , 6 , 7 , 8 ]. As phase separation is inevitable, a lot of effort has been done to control the apparent morphologies by various compatibilization methods, such as multi-step reactive extrusion [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ] and the addition of inorganic or hybrid nanoparticles [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ] and copolymers with various functionalities [ 23 , 24 , 25 , 26 , 27 , 28 ].…”