Iranian chemical communication 2423-4958 3 Issue 3, pp. 180-282,Serial No. 8 2015 07 01 Denture base polymers, poly methyl methacrylate improved using free radical copolymerization 276 282 1268 EN Abdoulhossien Massoudi Department of Chemistry, Payame Noor University, PB BOX 19395-4697, Tehran, Iran. Azam Louie Department of Chemistry, Payame Noor University, PB BOX 19395-4697, Tehran, Iran. Omid Louie Department of Chemistry, Payame Noor University, PO Box 19395-4697, Tehran, Iran Journal Article 2014 12 05 Poly methyl methacrylate (PMMA) is the most common material used in Prosthodontics. Several studies indicate a breakdown of the number of very high resin bases after 2 to 3 years to avoid breaking bass and several attempts have been made, such as altering the chemical structure of resin by adding causes cross linking or copolymerization. The innovative method for improving the physical properties of the prosthesis and increase its strength, a copolymer of styrene - methyl methacrylate was proposed. Tensile strength increased with the increase of styrene with methyl methacrylate in an amount determined to be the most resistant. Polystyrene and poly methyl methacrylate and copolymers characterized by FTIR, CNMR and Tg and tensile strength were measured according to ISO1567 standard. https://icc.journals.pnu.ac.ir/article_1268_9bab45f889d78d4bf6ca061f165e4ca4.pdf