Role of cross-linking process on the performance of PMMA

There is no doubt that, poly (methyl-methacrylate) (PMMA) is commercially used synthetic resin that produced via polymerization of its starting methyl-methacrylate monomer. It is a multipurpose amorphous thermoplastic polymer that is widely used in opticelectronic instruments like: surface boosted Raman scattering substrates,1 lightweight window,2 solar cells,3 light-emitting diode4 and battery5 because of its significant characteristics such as: its exceptional optical transparency, low-priced, mechanical properties, chemical resistance, and tremendous electrical.6 Also, PMMA is used commonly in electronic, surgical and dental supplies, as it is characterized by its resistance to several inorganic reagents, acidic and alkaline solutions, non-polar solvents, and aliphatic hydrocarbons.7,8 Unfortunately, the hydrophobic nature and lack of triggered organic groups on PMMA, its low mechanical dynamical properties under high temperature circumstances and thermal steadiness considered as drawbacks of PMMA that restricted its applications. There is an important well known method used to improve the properties of PMMA radically such as: its influence in the chemical, thermal, physical, morphological, and mechanical behavior of a polymer, which made it used potentially in different fields such as electronic applications,9 humidity sensors10 batteries.11 This method is called Cross-linking in which it tends to polymer modification by the process of interlinking the polymer chains through ionic or covalent bonds, in which it confines the polymer chains to slide past each other by impeding their free movement and produces elasticity in amorphous polymers at the same time, and this process can be carried out by using (i) chemical cross-linking or (ii) physical procedures.