Radiation Yield and Radicals Produced in Irradiated Poly (Butylene Succinate)

Abstract

RADIATION YIELD AND RADICALS PRODUCED IN IRRADIATED POLY(BUTYLENE SUCCINATE).The main chemical effects of ionizing irradiation on polymers are crosslinking and chain scission. Both processes occur simultaneously and their yields determine the final results of processing. The radiation yield of crosslinking could be determined by several methods depending on the characteristics of the material and properties of the gel. Radiation parameters of gelation, such as gelation dose and ratio of scission yield to crosslinking yield, as well as their values were estimated. In this study, those parameters depend on the amount of Trimethallyl isocyanurate (TMAIC) in Poly(butylene succinate) (PBS), molecular weight of PBS, and irradiation condition. In the absence of TMAIC, higher molecular weight of PBS required less energy to start gelation process compare to lower molecular weight of PBS. While in the presence of TMAIC all of the PBS samples require similar energy to start gelation process. The existence of macroradicals were observed by Electron Spin Resonance measurements. The result showed that the spectra consisted of signals derived from radicals on carbon nearby carbonyl, and signals derived from radicals on carbon reside between two similar carbon on polymer, both of radicals lead to crosslinking.

E-Beam Cross-Linking of Complex Hydrogels Formulation: The Influence of Poly(Ethylene Oxide) Concentration on the Hydrogel Properties

“…The radiation yields of cross-linking (G(X)) and degradation (G(S)) were calculated using the following equations [ 39 ]: where G(X) is expressed as the number of moles of cross-linking bonds per Joule, G(S) is the radiation yield of chain scission (mol/J), M C (kg/mol) is the average molecular weight between two successive cross-links, c (g/L) is the polymer concentration in the irradiated solution, D (J/kg) is the absorbed dose, and ρ (kg/m 3 ) is the polymer density.…”

Development of Novel Superabsorbent Hybrid Hydrogels by E-Beam Crosslinking

“…The radiation yields of crosslinking and degradation (scission) were calculated using the following equations: where G(X) is the radiation yield of crosslinking (expressed as number of moles of crosslinking bonds per Joule), G(S) is the radiation yield of chain scission (mol/J), M C (kg/mol) is the average molecular weight between two successive crosslinks, c (g/L) is the polymer concentration in irradiated solution, D is absorbed dose (J/kg), and ρ (kg/m 3 ) is the polymer density [ 52 ].…”

Modifikasi Selulosa Menggunakan Asamakrilat Dan Trimethallyl Isocianurate Dengan Metode Pra Iradiasi Peroksida

“…Pembentukan situs aktif pada polimer induk dapat dilakukan dengan dua cara, yakni metode kimia dan metode fisika. Pada metode kimia, radikal terbentuk pada selulosa akibat abstraksi atom hidrogen oleh radikal inisiator seperti Dibenzoyl Peroxide (BPO), Azoisisobutyronitrile (AIBN), atau bahan pengoksidasi garam cerium [7][8][9]. Diperoleh derajat grafting maksimum 87 % pada pencangkokan asam akrilat pada selulosa dengan teknik prairadiasi, pada suhu 60 o C selama 6 jam, menggunakan sistem vacuum dan gas nitrogen, tanpa agent pengikat silang [2].…”

“…Selain itu, pada dosis yang tinggi dapat menyebabkan degradasi kerangka selulosa akibat reaksi pemutusan rantai, karena selulosa tergolong dalam kelas polimer terdegradasi dengan proses radiasi. Imbas radiasi pada reaksi radikal dalam polimer dapat memulai untuk chain scission (pengurangan berat molekul polimer) dan cross linking (peningkatan berat molekul polimer) [7]. Selama iradiasi, radikal selulosa terbentuk dengan lokalisasi elektron tak berpasangan pada posisi 1 dan 4 dari cincin piranosa.…”