Structure and properties of poly(p‐xylylene) composites made by electrochemical and vapor deposition polymerization

Abstract

Poly(para‐xylylene)(PPX)/carbon fiber towpregs were produced by two different in‐situ polymerization processes: Electrochemcal polymerization (ECP) and vapor deposition polymerization (VDP). The monomer used for the ECP process was α, α′ ‐dibromo‐para‐xylylene and di‐para‐xylylene was the starting material for the VDP process. A series of tests, including FTIR, WAXD, DSC, TG, and SEM were carried out to identify and compare these two composite towpregs. It has been confirmed that the PPX samples obtained by the two different polymerization processes were basically chemically identical. However, the polymer coating on the fiber surface produced by the VDP process was much smoother than that produced by the ECP process, which produced a porous coating.

Increasing the robustness and crack resistivity of high-performance carbon fiber composites for space applications

“…A minimum of three PECLP-coated specimens were indented to a maximum depth of around 10% of their thickness (≈50 nm) to avoid substrate effects. Figure 3 A shows that the PECLP samples exhibit a tenfold greater elastic modulus (∼12 GPa, red bars) and approximately twofold greater hardness (∼1 GPa, blue bars) compared to the classical VDP poly(p-xylylene) films (∼1.2 GPa and 0.4 GPa, respectively).The values for the classically VDP poly(p-xylylene) films were commonly and consistently reported ( Mulpuri et al., 2012 ; Li et al., 1992 ; Zhang et al., 1995 ). This demonstrates the effectiveness of a virtual electrode PECVD process to manufacture the PECLP structures presented and the enhancements of PECLP over traditional poly(p-xylylene).…”

First polyrecombination reaction via atom transfer radical coupling (ATRC), a new way for the synthesis of poly(p-xylylene)

“…Zinc powder coated with nickel gave comparable results [21]. Coupling of α,α -dibromo-p-xylene at room temperature, mediated by potassium/18-crown-6 supramolecular complex, and electrochemical polymerization of the same compound [22] are other reported routes for synthesis of PPX. The lack of solubility at lower temperatures of PPX is one of the reasons that, although several models have been suggested [23,24], the mechanism of chain growth is not clear yet.…”

Highways for ions in polymers - 3D–imaging of electrochemical interphase formation

“…PPX may be produced in different modifications. A smooth uniform deposition of a semi-crystalline PPX film with crystallites in a modification with orthogonal orientation of the benzene rings relative to the surface and a ring to ring distance of 5.92 Å and 10.64 Å respectively is observed at a deposition at room temperature [16][17][18][19]. A transition from a modification to the hexagonal b-modification is an irreversible process occurring at 230 C [20].…”