Grafting modifications of plastics

Free radical grafting of maleic anhydride (MA) onto polyolefins has gained wide industrial use. MA modified polyolefins are an essential part of many plastics formulations. They are used as chemical coupling agents, impact modifiers, and compatibilisers for blends and filler reinforced systems [65-67]. 

Despite the large number of studies on MA grafting and the commercial success of MA grafted polyolefins, the chemical mechanism involved in the functionalisation process is not fully understood. Several studies have shown that the reaction pathways depend on the polyolefin molecular structure. When a peroxide is used as initiator, crosslinking or chain scission may occur simultaneously with the grafting reaction. The dominant side reaction for PE is crosslinking [68-76] and for PP is chain scission [77, 78]. 

Despite the progress that has been made, the effect of the polyolefin composition on MA grafting is still not fully understood, due to the lack of true insight into the reaction mechanism. Actually, most grafting studies have been carried out using different grafting recipes (type and amount of peroxide levels for PP). 

Composite wood products may be constructed using wood fibres, flakes, chips or shavings, veneers or paper. During the manufacturing process, these materials are often combined 

Particleboard (constructed from wood flakes, shavings or splinters) 

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