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Grafting Of Poly(meth)Acrylate On Polyolefinic Elastomers Via Controlled Radical Polymerization
Dhruba J. Haloi, Kinsuk Naskar, Nikhil K. Singha*
Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur-721302, India
Being non-polar in nature polyolefinic elastomers (POE) have poor compatibility towards polar fillers and polar polymers. They have also poor resistance to oils and fuels. Their bond-ability towards polar substrates is also poor. These limit their applications like in automotive industry, in the preparation of polymer blends with polar polymers etc. There are several reports on grafting of different polar monomers on different POEs, like on EPDM via conventional free radical polymerization (FRP). But this process leads to uncontrolled molecular weight, gelation and formation of homopolymer of the grafted monomer.
In recent years controlled radical polymerizations (CRP) are being used to prepare polymers with controlled molecular weights and with well-defined architecture. This investigation reports controlled grafting of poly(meth)acrylates on chlorinated polypropylene (CPP) as well as on EPDM via transition metal catalyzed CRP, widely known as atom transfer radical polymerization (ATRP). In this case 2-ethyl-hexyl acrylate (EHA) was grafted from CPP using CuBr as catalyst in combination with N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA) as ligand. This leads to brush-like graft copolymer with thermoplastic elastomeric material. In this investigation PMMA as well as PEHA were also grafted from EPDM via reverse ATRP using AIBN as an initiator and CuBr/PMDETA as catalyst. The resultant polymer was free from gelation and homopolymers of acrylates. The grafted copolymers were characterized by FT-IR, IHNMR, DSC & TGA analyzes. The morphology of the polymers was analyzed by AFM and SEM analyzes.
*Corresponding author. E-mail: nks@rtc.iitkgp.ernet.in;
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