Mechanism of aging of poly[1-(trimethylsilyl)-1-propyne] and its effect on gas permeability

The effects of different mechanisms of aging of poly[1-(trimethylsilyl)-1-propyne] (PTMSP), namely, chemical aging (oxidation), physical and absorption aging, on gas permeability of the polymer were studied. For this purpose, the PTMSP samples obtained in the presence of various catalysts (TaCl5/BuLi, TaCl5/i-Bu3Al, and NbCl5) and stored at ambient temperature for 2–8 years were investigated. The procedure involving the stages of sequential dissolving, precipitation and recasting allowed us to recognize the contributions of different mechanisms of aging. It was shown that a long-term storage of PTMSP at ambient conditions results in oxidation of the polymer with formation of various functional groups (aldehyde, acid, ether, and epoxy groups). The dissociation of the main chain takes place as well with formation of low molecular mass products. It was shown, however, that is not the main reason for a reduction of gas permeability of PTMSP. The absorption aging of PTMSP provides the main contribution in decreases in gas permeability of aged PTMSP samples. Its consequences can be eliminated by the re-precipitation of the polymer from its solutions and subsequent recasting. Unusual behavior of aged PTMSP samples in separating of the C1–C3 hydrocarbons is also observed and discussed.

[1]  E. M. Antipov,et al.  Transport characteristics and other physicochemical properties of aged poly (1-(trimethylsilyl)-1-propyne) , 1993 .

[2]  T. Masuda,et al.  Gas permeability of polyacetylenes carrying substituents , 1985 .

[3]  T. Masuda,et al.  Synthesis of poly[1-(trimethylsilyl)-1-propyne] with extremely high molecular weight by using tantalum pentachloride-triphenylbismuth (1:1) catalyst , 1986 .

[4]  K. Nitta,et al.  Effects of Physical Aging on Viscoelastic and Ultrasonic Properties of Poly[1-(trimethylsilyl)-1-propyne] Films , 1992 .

[5]  I. Pinnau,et al.  Synthesis and gas permeation properties of poly(4-methyl-2-pentyne) , 1996 .

[6]  K. Nagai,et al.  Gas permeability and stability of poly(1-trimethylsilyl-1-propyne-co-1-phenyl-1-propyne) membranes , 1995 .

[7]  L. Robeson,et al.  Substituted propyne polymers—part II. Effects of aging on the gas permeability properties of poly[1‐(trimethylsilyl)propyne] for gas separation membranes , 1989 .

[8]  V. Zaikin,et al.  Thermal oxidation of poly(1-trimethylsilylprop-1-yne) studied by IR spectroscopy , 2003 .

[9]  L. Robeson,et al.  High performance polymers for membrane separation , 1994 .

[10]  W. L. Robb,et al.  THIN SILICONE MEMBRANES‐THEIR PERMEATION PROPERTIES AND SOME APPLICATIONS , 1968, Annals of the New York Academy of Sciences.

[11]  K. Nagai,et al.  Effects of Aging on Molecular Motion of Poly(1-trimethylsilyl-1-propyne) Membranes Synthesized Using Vanous Catalysts , 1996 .

[12]  A. Savoca,et al.  Gas transport in poly(silylpropynes) : the chemical structure point of view , 1993 .

[13]  K. Nagai,et al.  Poly[1-(trimethylsilyl)-1-propyne] and related polymers: Synthesis, properties and functions , 2001 .

[14]  Y. Yampolskii,et al.  Estimation of free volume in poly(trimethylsilyl propyne) by positron annihilation and electrochromism methods , 1993 .

[15]  B. Freeman,et al.  Polymer characterization and gas permeability of poly(1‐trimethylsilyl‐1‐propyne) [PTMSP], poly(1‐phenyl‐1‐propyne) [PPP], and PTMSP/PPP blends , 1996 .

[16]  E. G. Litvinova,et al.  Gas and vapor permeation and sorption in poly (trimetylsilylpropyne) , 1991 .

[17]  M. Anand,et al.  Substituted propyne polymers , 1988 .

[18]  T. Masuda,et al.  Polymerization of 1-(trimethylsilyl)-1-propyne by halides of niobium(V) and tantalum(V) and polymer properties , 1985 .

[19]  S. Tasaka,et al.  Effect of annealing on structure and permeability of poly [(l‐trimethylsilyl)‐l‐propyne] , 1991 .

[20]  敏延 東村,et al.  ポリ [1- (トリメチルシリル) -1-プロピン] 膜への気体の透過 , 1986 .

[21]  T. Nakagawa,et al.  Polyacetylene derivatives as membranes for gas separation , 1988 .

[22]  P. Stein,et al.  A study by solid-state and solution carbon-13 NMR on silicon-containing polyacetylenes , 1991 .

[23]  N. Toshima.  Polymers for gas separation , 1992 .

[24]  Y. Ichiraku,et al.  An investigation of the high gas permeability of poly (1-Trimethylsilyl-1-Propyne) , 1987 .

[25]  V. Volkov.  Free Volume Structure and Transport Properties of Glassy Polymers—Materials for Separating Membranes , 1991 .

[26]  B. Tang,et al.  Thermal degradation of polyacetylenes carrying substituents , 1985 .

[27]  T. Merkel,et al.  Sorption and transport of hydrocarbon and perfluorocarbon gases in poly(1-trimethylsilyl-1-propyne) , 2000 .

[28]  R. Srinivasan,et al.  Elucidating the mechanism (s) of gas transport in poly[1-(trimethylsilyl)-1-propyne] (PTMSP) membranes , 1994 .

[29]  T. Masuda,et al.  Study on the geometric structure of poly[1-(trimethylsilyl)-1-propyne] by 13C and 29Si NMR spectroscopies , 1991 .

[30]  Eiji Isobe,et al.  Poly[1-(trimethylsilyl)-1-propyne]: a new high polymer synthesized with transition-metal catalysts and characterized by extremely high gas permeability , 1983 .

[31]  G. Baker,et al.  Cross-linking of poly[1-(trimethylsilyl)-1-propyne] membranes using bis(aryl azides) , 1998 .

[32]  J. H. Adams.  Analysis of the nonvolatile oxidation products of polypropylene I. Thermal oxidation , 1970 .

[33]  B. Tang,et al.  Diffusion and solution of gases in substituted polyacetylene membranes , 1988 .

[34]  T. Masuda,et al.  Polyacetylenes with substituents: Their synthesis and properties , 1987 .

[35]  Lora G. Toy,et al.  Transport of organic vapors through poly(1-trimethylsilyl-1-propyne) , 1996 .

[36]  K. Nagai,et al.  Effect of physical aging of poly(1-trimethylsilyl-1-propyne) films synthesized with TaCl5 and NbCl5 on gas permeability, fractional free volume, and positron annihilation lifetime spectroscopy parameters , 2000 .

[37]  Giovanni Consolati,et al.  Positron annihilation lifetime (PAL) in poly[1‐(trimethyl‐silyl)propine] (PTMSP): Free volume determination and time dependence of permeability , 1996 .

[38]  K. Nagai,et al.  Oxidation of poly(1-trimethylsilyl-1-propyne) , 1994 .

[39]  Kazukiyo Nagai,et al.  Effects of aging on the gas permeability and solubility in poly(1-trimethylsilyl-1-propyne) membranes synthesized with various catalysts , 1995 .

[40]  R. Chern,et al.  Sorption and transport of organic vapors in poly[1-(trimethylsilyl)-1-propyne] , 1990 .

[41]  A. Higuchi,et al.  Physical modification of poly [1(trimethylsilyl)-1-propyne] membranes for gas separation , 1994 .