Microsoft powerpoint - 08benny.ppt [compatibility mode]
Stable Free Radical Assisted Peroxide Vulcanisation: Cure characteristics and vulcanisate properties Benny George and Rosamma Alex Rubber Technology Division Advanced Center For Rubber Technology Rubber Research Institute of India Kottayam, Kerala, India. IRC & IRRDB Meeting, 29 October to 2 November 20012, Kovalam, Kerala Vulcanisation Viscous raw rubber Elastic material Time Line History of Sulphur Vulcanization Sulphur vulcanization Vulcanizing agent Unacclerated sulphur vulcanization Thiocarbanilide Dithiocarbamates Accelerated sulphur vulcanization Diphenyl guanidine accelerators 2- Mecaptobenzothiazol 2- Benzothiazolyl disulphide 2- Alkylamino thiobezothiazole (sulphenamide) Delayed action sulphur vulcanization Premature N cyclohexyl thiophthalimide vulcanization inhibitor Time Line History of Peroxide Vulcanization Benzoyl Peroxide Peroxide Vulcanization 1950 Various Peroxides and co-agents Advantages 1. No reversion at higher cure temperatures 2. Low compression set 3. Excellent heat ageing resistance 4. Co-vulcanisation of saturated and unsaturated rubber blends Cure behavior comparison Time, min Time, min Peroxide Sulphur/accelerator DCP/TEMPO/ bismaleimide system for sulphur/ accelerator like scorch control* Time, min *Benny George and Rosamma Alex, Delayed action peroxide vulcanisation, IRC , Mumbai, 2010 Matreials used PERKADOX14-40B Di(tert-butylperoxyisopropyl)benzene TRIGNOX 17-40 B Butyl 4,4-di(tert-butylperoxy valerate) Co-agents SR25 - N,N’-m-phenylene dimaleimide (Type I) SR350 - Trimethylolpropane trimethacrylate (Type I) 2,2,6,6-tetramethylpiperidine -1- oxyl Effect of concentration of TEMPO on cure characteristics of Trignox 17-40B at 1600C Effect of concentration of TEMPO on cure characteristics of Perkadox 14-40B at 1750C rque (dNm 40 Time (minutes) Perkadox Comparison of MH-ML value Trignox 17-40 B Perkadox 14-40 B duc e 10 R % Concentration of TEMPO Effect of cure temperature on on cure characteristics of Trignox 17-40B* at 0.8 phr TEMPO rque (dNm o Time (minutes) No Temperature, ML, Effect of cure temperature on cure characteristics of Perkadox 14-40B * at 0.8 phr TEMPO rque (dNm o T Time (minutes) No Temperature, ML, Effect of co-agent on cure characteristics of Trignox 17-40B/TEMPO at 1600C rque (dNm o Time (minutes) Effect of coagent on cure characteristics of Perkadox 14-40B /TEMPO at 1750C rque (dNm 40 Time (minutes) Mechanism of scorch control Advatage of using Perkadox14-40B /TEMPO/SR350 1. Excellent scorch safety 2. Easy to release from the Mould 3. Enable to mould thicker articles which requires the excellent properties offered by peroxide vulcanisation Cure Characteristics of bulk compound at 1750C Compound EPDM Control 25.7 128.2 102.3 EPDM/Perkadox14- 105.0 85.8 40B/TEMPO/SR 350 Vulcanisate properties Properties EPDM control EPDM/Perkado x 14-40B/ TEMPO/SR 350 Tensile strength, MPa Modulus,100%, MPa Modulus,200%, MPa Modulus,300%, MPa Tear strength, N/mm Hardness, Shore A Compression set, 1000C, 72 h Conclusions 1. Sulphur accelerator like scorch control in peroxide vulcanisation can be achieved using a stable free radical/co-agent system 2. Perkadox14 {Di(t-butyl peroxyisopropyl)benzene/TEMPO/SR350 (trimethylol propane trimethacrylate ) system has the potential to be utilised by the manufacturing industry. 3. The vulcanisate properties of the TEMPO containing vulcanisates are comparable with that of the control compound. Thank you
New Contraceptives and Other Advances in Reproductive Health Emergency Contraception Plan B and Preven are two emergency contraceptive pill products (also called “dedicated products”)currently available to women with a doctor’s prescription. While the ingredients in these productsdiffer, both Plan B and Preven should be taken within 72 hours of unprotected intercourse. Thesooner t
Gebruik van Echinaforce tabletten in combinatie 1. Wat zijn A.Vogel Echinaforce tabletten Echinaforce tabletten kan in combinatie met 3. Hoe worden A.Vogel Echinaforce tabletten Gebruik van Echinaforce tabletten tijdens Echinaforce tabletten niet gebruiken tijdens de 5. Hoe bewaart u A.Vogel Echinaforce tabletten?zwangerschap en periode van borstvoeding. Rijvaardigheid en het gebruik van m