Evolution of reactive unsaturated interfacial modifiers for polyolefin based composites

• Published in: Composite interfaces Vol. 13; no. 8-9; pp. 717 - 736
• Main Authors: Liauw, Christopher Mark, Lees, Graham Clayton, Rothon, Roger Norman, Voliotis, Anastasios, Wild, Frank, Sunderland, Patrick, Schofield, John, Thetford, Dean
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.01.2006
• Subjects: ALUMINIUM HYDROXIDE; CALCIUM CARBONATE; COMPOSITE; COUPLING AGENT; FILLER SURFACE TREATMENT; MAGNESIUM HYDROXIDE; POLYOLEFIN
• ISSN: 0927-6440; 1568-5543
• DOI: 10.1163/156855406779366750

The development of a novel reactive unsaturated interfacial modifier for filled (magnesium hydroxide, aluminium hydroxide and calcium carbonate) polyolefins is reviewed. Initial work explored maleimide functional candidate molecules including 1,3-phenylene dimaleimide (1,3-PDM) and a range of linear alkyl dimaleimides. Most of the dimaleimides were very effective interfacial modifiers in polypropylene and poly(ethylene-co-vinylacetate) (18% w/w vinylacetate) based composites. However, the dimaleimides caused the composites to have a distinct pink/brown colouration apart from when the maleimide groups were spaced by a C12 alkyl chain. The problem with colour and high effective dosage prompted a switch to unsaturated carboxylic acid based systems. The performance of a range of unsaturated carboxylic acids and the hexafunctional monomer trimethylolpropane triacrylate are reviewed, together with a novel oligomeric unsaturated carboxylic acid (OUCA) based system developed by the Noveon Division of Lubrizol Limited. The data obtained from this series of interfacial modifiers, and adsorption studies on 1,3-PDM and OUCA, afforded some insight into the competing factors (such as the strength of adsorption versus ability to form a polymerised interfacial layer and the ability to react with matrix chains) that significantly affect the coupling performance of interfacial modifiers.