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Polydimethylsiloxane. 化工四 B95504050 劉邦彥 B95504048 彭子軒 B95504052 林文翔. Questions Review. Tyler mesh size is the number of openings per (linear) inch of mesh. 1800 mesh = 10 μ m 100~6000 mesh = 3~149 μ m. Questions Review. DMDCS. H2O HCl. Rochow. S1. Hydrolysis. S2. D4 MD2M.
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Polydimethylsiloxane 化工四 B95504050 劉邦彥 B95504048 彭子軒 B95504052 林文翔
Questions Review • Tyler mesh size is the number of openings per (linear) inch of mesh. • 1800 mesh = 10 μm • 100~6000 mesh = 3~149 μm
Questions Review DMDCS H2O HCl Rochow S1 Hydrolysis S2 D4 MD2M CH3Cl XMXCS H2O Cyclization DMDCS CH3OH HCl Rochow Methanolysis S1 H2O CH3Cl S3 S2 Cyclization D4 MD2M CH3Cl Avoid acid waste ,making the process cleaner and more efficient. H2O
Ring-Open Polycondensation • Yield high polymer from ROP of cyclic oligomer. • Allow to synthesis high Mn with great precision. • Formation of PDMS from D4 is commonly used in industry. • Two kinds of ROP: • Anionic Polymerization • Cationic Polymerization
Anionic Polymerization Initiation Propagation
Anionic Polymerization • Catalyst: KOH • Condition: 0.01% 140℃ • Product: • Mn: 8.84×105 • Rxn Time: 90min • Conversion: 84% • HP conversion: 76% • Solubility Problem
Cationic Polymerization Initiation Propagation
Cationic Polymerization • Catalyst: CF3SO3H H2SO4 • Condition: 8.7×10-4M 20℃ • Product: • Mn: 1.4×105 • Rxn Time: 90min • Conversion: 85% • HP Conversion: 60% • Corrosion Problem. • Triflic acid: 140,000 NTD/kg
Ring-Open Polycondensation • Small cyclic siloxane will be formed. [D4]o= 1.19M; [TfOH]0 = 8.47.10-4 M
Viscosity • Mn Range: 105~106 • Viscosity: • At 140℃[cP]: ~105 • At 25℃[cP]: 105~106 • PFR is available.
Future Work • Reaction constant search. • Process model establishment.
Reference • P. DUBOIS, O. COULEMBIER, and J.-M. RAQUEZ, Handbook of Ring-Opening Polymerization, Wiley-VCH Verlag GmbH & Co. KGaA Weinheim 2009, pp. 65-76 • W. T. GRUBB AND ROBERT C. OSTHOF, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY77 (1955)1405-1411 • S. P. GUPTA, M. MOREAU, M. MASURE and P. SIGWALT, Polym. J.29 (1993) 15-22 • E. S. WILKS, Industrial Polymers Handbook, vol.3, Wiley-VCH Verlag GmbH & Co. KGaA Weinheim • https://www.spectrumchemical.com/OA_HTML/ibeCSrdSrchResults.jsp?cg=-200&kw=T2105&ds=0&dr=25&st=kw&cpg=0&minisite=10020&site=&respid=50577 • http://en.wikipedia.org/wiki/Viscosity • http://en.wikipedia.org/wiki/Mesh_(scale)