Grafting of maleic anhydride onto polypropylene: Synthesis and characterization
ABSTRACT Isotactic polypropylene was grafted with maleic anhydride using benzoyl peroxide as an initiator and toluene as a solvent. Effects of various parameters such as monomer and initiator concentration, reaction time, and reaction temperature on percentage grafting were studied. Effect of various solvents on extent of grafting was also studied. The maximum extent of grafting achieved was 5.3%. The graft copolymers were characterized by i.r., thermal, viscometric, and contact angle studies. Improved thermal stability and decreased intrinsic viscosity and critical surface tension were observed for graft copolymers. © 1994 John Wiley & Sons, Inc.
- SourceAvailable from: Zakir M.O. Rzayev[Show abstract] [Hide abstract]
ABSTRACT: This review summarizes the main advances published over the last 15 years outlining the different methods of grafting, including reactive extruder systems, surface modification, grafting and graft copolymerization of synthetic and natural polymers with maleic anhydride and its isostructural analogues such as maleimides and maleates, and anhydrides, esters and imides of citraconic and itaconic acids, derivatives of fumaric acid, etc. Special attention is spared to the grafting of conventional and non-conventional synthetic and natural polymers, including biodegradable polymers, mechanism of grafting and graft copolymerization, in situ grafting reactions in melt by reactive extrusion systems, in solutions and solid state (photo- and plasma-induced graftings), and H-bonding effect in the reactive blend processing. The structural phenomena, unique properties and application areas of these copolymers and their various modifications and composites as high performance engineering materials have been also described.
- [Show abstract] [Hide abstract]
ABSTRACT: In this work, polypropylene grafted maleic anhydride (PP-g-MA) prepared by solution process was used as a compatibilizer for polypropylene (PP)/polyamide 6 (PA6) blends. PP with melt flow index (MFI) of 10 g/10 min was grafted with maleic anhydride (MA) using benzoyl peroxide (BPO) as an initiator and toluene as a solvent. The effects of BPO and MA concentration on the grafting degree of MA onto PP were studied. The grafting degree was determined by a back-titration procedure whereas the formation of graft copolymers was confirmed by FT-IR technique. It was found that the maximum extent of grafting achieved was 0.87%. Blend of PP (MFI of 25 g/10 min) and PA6 with weight ratio of 70/30 was prepared by twin screw extruder. The prepared PP-g-MA (0.87% grafting) was used as a compatibilizer at the amount of 5 and 10 parts per hundred of the blend. The testing specimens were prepared by injection molding machine. The results showed that the tensile strength of the compatibilized blends was substantially higher than that of the uncompatibilized blend whereas percent elongation and Young's modulus were comparable. Morphology of the blends investigated by SEM technique disclosed that the compatibilized blends exhibited a remarkable decrease in size of the dispersed domain. TGA and DSC were employed to investigate thermal behaviors of the blends. PP-g-MA had a slight influence on the thermal stability of the blends. The crystallization rate of PP in the blends was higher than that of the neat PP. On the contrary, the presence of PP reduced the crystallization rate of PA6 in the blends. Key word : PP-g-MA, solution process, compatibilizer, polypropylene, polyamide 6
- [Show abstract] [Hide abstract]
ABSTRACT: This paper details the characteristics of pure cellulose and wood fibers when associated with thermoplastic matrices for composite applications. Chemical modification of the cellulose is performed to allow a good compatibilization, and the most efficient compatibilizing agents must possess: (i) a function highly reactive with the OH groups of the cellulose and (ii) a non-polar chain with preferably a polymeric structure. Polypropylenes grafted with maleic anhydride are thus efficient agents. Smaller compatibilizing agents, especially if reacted with cellulose in swelling media, react with the bulk of the fiber and lead to dimensional stability. All treatments, even when performed with low degrees of grafting or small alkyl chains, significantly modify the hydrophilicity of the cellulose surface and play a role in a better wettability of the fiber by the matrix leading to improved adherence. The global mechanical properties are then improved, but the effect is preferably studied at the scale of a single filament composite. The morphology of the matrix in the vicinity of the non-treated fiber shows that, in some cases, the fiber acts as a nucleating agent involving the formation of a transcrystalline phase. Aging in moisture is generally detrimental to the mechanical properties. This phenomenon is limited by the chemical treatment performed on the fibers.Polymer Composites 06/1998; 19(3):287 - 300. DOI:10.1002/pc.10102 · 1.46 Impact Factor