Keywords
Crystalline · Gas transport property · Liquid polymer · Crystalline structure · Gas
barrier · Phase transition
Definition
The gas transport properties of a polymer membrane are not only affected by its
physical properties but also by the difference of its crystalline structure (e.g.,
crystalline, liquid crystalline, and amorphous). Several studies have reported the
relationship between crystalline structure and gas transport properties, and this
relationship is important in the design of various polymer materials. In this chapter,
the effects of permeability, solubility, diffusivity of each polymer film on the
transport properties of various gas molecules are explained based on data from
literature.
Introduction
Recently, polymer science research has focused on membrane materials that have
precise, highly ordered structures, such as those that are crystalline or have a wellordered orientation. Polymers are generally amorphous or semi-crystalline. The
latter is also called a partially crystalline polymer and consists of a complex
combination of crystalline and amorphous regions. In the crystalline region, polymer
segments are packed parallel to each other and form a phase of finite size. Small
molecules only pass through the amorphous region because the polymer chain
mobility is considerably restricted in the crystalline phase, thereby causing difficulties in diffusion and dissolution (Paul and Yampol’ skii 1994).
To date, a large number of physical and transport properties for different gases,
including oxygen (O 2 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ) have been studied
in crystalline and liquid crystalline polymers. As shown in Fig. 1, these polymers
include polyethylene (PE) (Waack et al. 1955; Alter 1962; Michaels and Parker
1959; Michaels and Bixler 1961a; Bixler et al. 1963; Holden et al. 1985; Bernal-Lara
et al. 2005; Mendes et al. 2004; Compan et al. 1998, 1997; Kofinas et al. 1994; Ash
et al. 1970; Srinivas et al. 2003), poly[bis(trifluoroethoxy phosphazene)] (PTFEP)
(Hirose et al. 1989; Nagai et al. 2000; Mizoguchi et al. 1991), polypropylene (PP)
(Kofinas et al. 1994; Vieth and Wuerth 1969; Somlai et al. 2005; Lin et al. 2008a, b;
Incarnato et al. 2000), poly(4-methyl-1-pentene) (PMP) (Puleo et al. 1989; Mohr and
Paul 1991; Levaesalmi and McCarthy 1995), poly(lactic acid) (PLA) (Komatsuka
et al. 2008; Komatsuka and Nagai 2009; Sawada et al. 2010; Lehermeier et al. 2001;
Auras et al. 2003; Bao et al. 2006), polyethylene terephthalate (PET) (Michaels
et al. 1963; Qureshi et al. 2000; Polyakova et al. 2001; Hu et al. 2002a, 2005a, b;
Liu et al. 2004), polystyrene (PS) (Hodge et al. 2001; Prodpran et al. 2002), polyacrylate (PA) (Mogri and Paul 2000a, b, 2001a, b; O’Leary and Paul 2006a, b;
524
S. Ando et al.
Crystalline · Gas transport property · Liquid polymer · Crystalline structure · Gas
barrier · Phase transition
Definition
The gas transport properties of a polymer membrane are not only affected by its
physical properties but also by the difference of its crystalline structure (e.g.,
crystalline, liquid crystalline, and amorphous). Several studies have reported the
relationship between crystalline structure and gas transport properties, and this
relationship is important in the design of various polymer materials. In this chapter,
the effects of permeability, solubility, diffusivity of each polymer film on the
transport properties of various gas molecules are explained based on data from
literature.
Introduction
Recently, polymer science research has focused on membrane materials that have
precise, highly ordered structures, such as those that are crystalline or have a wellordered orientation. Polymers are generally amorphous or semi-crystalline. The
latter is also called a partially crystalline polymer and consists of a complex
combination of crystalline and amorphous regions. In the crystalline region, polymer
segments are packed parallel to each other and form a phase of finite size. Small
molecules only pass through the amorphous region because the polymer chain
mobility is considerably restricted in the crystalline phase, thereby causing difficulties in diffusion and dissolution (Paul and Yampol’ skii 1994).
To date, a large number of physical and transport properties for different gases,
including oxygen (O 2 ), nitrogen (N 2 ), and carbon dioxide (CO 2 ) have been studied
in crystalline and liquid crystalline polymers. As shown in Fig. 1, these polymers
include polyethylene (PE) (Waack et al. 1955; Alter 1962; Michaels and Parker
1959; Michaels and Bixler 1961a; Bixler et al. 1963; Holden et al. 1985; Bernal-Lara
et al. 2005; Mendes et al. 2004; Compan et al. 1998, 1997; Kofinas et al. 1994; Ash
et al. 1970; Srinivas et al. 2003), poly[bis(trifluoroethoxy phosphazene)] (PTFEP)
(Hirose et al. 1989; Nagai et al. 2000; Mizoguchi et al. 1991), polypropylene (PP)
(Kofinas et al. 1994; Vieth and Wuerth 1969; Somlai et al. 2005; Lin et al. 2008a, b;
Incarnato et al. 2000), poly(4-methyl-1-pentene) (PMP) (Puleo et al. 1989; Mohr and
Paul 1991; Levaesalmi and McCarthy 1995), poly(lactic acid) (PLA) (Komatsuka
et al. 2008; Komatsuka and Nagai 2009; Sawada et al. 2010; Lehermeier et al. 2001;
Auras et al. 2003; Bao et al. 2006), polyethylene terephthalate (PET) (Michaels
et al. 1963; Qureshi et al. 2000; Polyakova et al. 2001; Hu et al. 2002a, 2005a, b;
Liu et al. 2004), polystyrene (PS) (Hodge et al. 2001; Prodpran et al. 2002), polyacrylate (PA) (Mogri and Paul 2000a, b, 2001a, b; O’Leary and Paul 2006a, b;
524
S. Ando et al.