Melt grafting

Kim el al. [582] have described maleimide-based antioxidants melt grafted onto low-MW PE. IR spectroscopic methods and titration were used for the quantitative determination of the extent of grafting of the monomeric antioxidant. Smedberg el al. [583] have characterised polymer-bound stabilisers by FTIR and NMR. The binding of antioxidants and photostabilisers to polyurethanes was verified by tJV/VIS spectroscopy [584]. 

Non-polymerisable monofunctional antioxidants were subsequently used to avoid the problem of homopolymerisation of the antioxidant. For example, melt grafting of the two maleated antioxidants, BPM and APM, on PP was shown to lead to high grafting efficiencies (up to 75% in the former and >90% in the latter) which were attributed to the non-polymerisable nature of the maleate (maleimide) functions [57, 59, 60]. The performance of these antioxidants, especially under extractive organic solvent conditions, was also shown to far exceed that of conventional antioxidants with similar antioxidant functions. Table 2, for example, shows the advantages of the grafted... 

The use of reactive antioxidants containing two polymerisable polymer-reactive functions in the same antioxidant molecule is outlined here. Careful choice of the processing parameters, the type, and the amount of free radical initiator can lead to very high levels of antioxidant grafting [53, 57]. For example, melt grafting of concentrates (e.g. 5-20 wt%) of the di-acrylate hin-... 

Table 4 Comparison of the antioxidant performance (accelerated UV ageing) of synergistic mixture (melt grafted in presence of Tris) with a conventional antioxidant mixture based on the same antioxidant functions (at 1 1 w/w ratio)...

The second system was based on two semi-crystalline polymers polypropylene and polyamide. To attain potential reactivity, polypropylene was first grafted with maleic anhydride and the results of this radicalar melt-grafting are presented. The final blend was obtained in one-step extruding of the two homopolymers and the reactive polypropylene. 

Functionalization of isotactic polypropylene with maleic anhydride by reactive extrusion mechanism of melt grafting. Polymer, Vol. 42, pp. 5549-5557, ISSN 0032-3861. 

The mechanism proposed for the grafting of maleic anhydride on to PE is shown in Figure 23. NMR analysis of the solution and melt grafting eiqjeriments showed that a mass fraction of 1 % of the [2,3 MA was incorporated into the PE via the melt grafting technique, and a mass fraction of4 % was incorporated into the PE via solution grafting. Analysis of the NMR data also showed that... 

Li, C., Zhang, Y, and Zhang, Y. 2003. Melt grafting of maleic anhydride onto low-density polyethylene/polypropylene blends. Polymer Testing 22 191-195. 

Grigoryeva, O. P. and Karger-Kocsis, J. 2000. Melt grafting of maleic anhydride onto an ethylene-propylene-diene terpolymer (EPDM). European Polymer Journal 36 1419-1420. 

PA-6/EPDM-g-MA One-step melt grafting and copolymer formation/ SEM/DSC/selective solvent extraction/FTIR/ NMR/mechanical properties/comparison to two-step process ColtelU et al. 2006 (see also Komalan et al. 2008)... 

Figure 3. TGA traces of short delignified bamboo fiber reinforced composites in presence of -—in situ melt grafting of maleic anhydride (MA)/ glycidyl methacrylate (GMA) (wj =first weight loss, w =...

Figure 5. Effect of —in siw melt grafting of maleic anhydride (MAVglycidyl methacrylate (GMA) on the melting behavior of SDBF reinforced composites (A) first and (B) second heating scans represents crystallinity index).

Chen, E. E., Wong, B., and Baker, W. E. (1996). Melt-grafting of glycidyl methacrylate onto polypropylene and reactive compatibilization of rubber toughened polypropylene. Polymer Engineering and Science 36(12), 1594-1607. 

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