Crystallization during polymerization of poly‐p‐xylylene. II. Polymerization at low temperature

Abstract

The polymerization of p‐xylylene was followed with a newly designed differential thermal analysis system at temperatures between −196°C and −20°C. It was found that at the lower temperatures the monomer condenses first to the crystalline monomer before simultaneous polymerization and crystallization. At the higher temperatures, polymerization and crystallization are successive. The data are in agreement with the morphology and crystal structure data derived in Part I of this series of papers on crystallization during polymerization of poly‐p‐xylylene.

Structure and optical properties of thin poly(p-xylylene) – Silver nanocomposite films prepared by low-temperature vapor deposition polymerization

“…In this case, the observed preferable orientation of the polymer chains is parallel to the substrate surface. For the b polymorph, the crystallization during polymerization at low deposition temperatures does not provide any noticeable orientation of the chains with respect to the substrate surface [22,23]. This model was later confirmed by Gazicki et al [24].…”

“…Two crystalline modifications (a and b phases) of PPX are documented in the literature [22,23]. The crystal structure of the a polymorph is monoclinic with the unit cell dimensions a ¼ 5.92 Å, b ¼ 10.64 Å, c ¼ 6.55 Å (chain axis) and b ¼ 134.7 .…”

“…The formation of predominantly a or b polymorph depends on the deposition conditions [22,23]. The effect of the deposition temperature on the crystalline structure of PPX was investigated by Kubo and Wunderlich [221,2].…”

Effects of the film thickness on the morphology, structure, and crystal orientation behavior of poly(chloro‐p‐xylylene) films

“…Parylene polymers are semicrystalline thermoplastics and are often synthesized as thin films by the chemical vapor deposition (CVD) method. The deposition conditions (deposition temperature, pressure, substrate, and so on) consequently play crucial roles in the morphology, microstructure, and properties of the films . However, some other factors, such as the thermal history of the polymer films, can also severely influence the degree of crystallization, crystallite size, stress state, and thermal stability of the films .…”

“…The deposition conditions (deposition tempera-ture, pressure, substrate, and so on) consequently play crucial roles in the morphology, microstructure, and properties of the films. [12][13][14][15][16][17] However, some other factors, such as the thermal history of the polymer films, can also severely influence the degree of crystallization, crystallite size, stress state, and thermal stability of the films. 13,14 Furthermore, because Parylene films with various thicknesses in a broad range are used in many different fields; the effect of the thickness on their structure is another important aspect that should be taken into great consideration.…”