Process for nanostructuring carbon fibers embedded in FRPS based on the use of sulphur in combination with aromatic hydrocarbon groups and on the use of laser radiation

Abstract

A process for the nanostructuring of fibers in fiber-composite plastics, where a sulfur-containing nanostructure is formed. Also, a plastics matrix with such nanostructured fibers is disclosed, and also a process for the repair of fibers in a fiber-composite plastic.

Claims

1. A process for nanostructuring of a fiber-composite plastic, comprising: providing a fiber-composite plastic comprising fibers and a plastics matrix comprising at least one sulfur-containing polymer; and using pulsed radiation for repeated irradiation of the fiber-composite plastic, where accumulated energy input due to the radiation is in a range from above 1.2 to below 50 J/cm.sup.2, and where energy input due to radiation in a wavelength range of 1000 nm and above does not exceed 2 J/cm.sup.2 per pulse.

2. The process as claimed in claim 1, where the irradiation uses radiation in a wavelength range of 100 to 650 nm.

3. The process as claimed in claim 1, where the nanostructuring takes place on at least one surface of the fiber-composite plastic.

4. The process as claimed in claim 1, where the fibers are selected from the group consisting of carbon fibers, glass fibers and metal fibers.

5. The process as claimed in claim 1, where the nanostructuring takes place on exposed fibers, where, before the nanostructuring, the fibers are exposed by a milling procedure, sandblasting and/or a grinding procedure.

6. A process for nanostructuring of a fiber-composite plastic, comprising: providing a fiber-composite plastic comprising fibers and a plastics matrix; applying at least one sulfur-containing monomer to the plastics matrix; and using pulsed radiation for repeated irradiation of the at least one sulfur-containing monomer and of the fiber-composite plastic, where accumulated energy input due to the radiation is in a range from above 1.2 to below 50 J/cm.sup.2, and where energy input due to radiation in a wavelength range of 1000 nm and above does not exceed 2 J/cm.sup.2 per pulse.

7. A process for repair of at least one fiber in a fiber-composite plastic, where a plastics matrix comprises at least one sulfur-containing polymer, where pulsed radiation is used for repeated irradiation of the fiber-composite plastic at least in a region of the at least one fiber, where accumulated energy input due to the radiation is in a range from above 1.2 to below 50 J/cm.sup.2, and where energy input due to radiation in a wavelength range of 1000 nm and above does not exceed 2 J/cm.sup.2 per pulse, and/or where a sulfur-containing monomer is applied to the plastics matrix at least in a region of the at least one fiber and pulsed radiation is used for repeated irradiation of the fiber-composite plastic at least in a region of the at least one fiber, where accumulated energy input due to the radiation is in a range from above 1.2 to below 50 J/cm.sup.2, and where energy input due to radiation in a wavelength range of 1000 nm and above does not exceed 2 J/cm.sup.2 per pulse.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure herein is explained in more detail below with reference to the inventive examples provided in the figures, which show:

(2) In FIGS. 1-8, micrographs of modified fibers in inventive examples and comparative examples of the disclosure herein.

DETAILED DESCRIPTION

(3) The attached figures are intended to increase understanding of the embodiments of the disclosure herein. They illustrate embodiments, and serve in conjunction with the description to explain principles and concepts of the disclosure herein. Other embodiments, and many of the advantages mentioned, are apparent from study of the drawings.

Inventive Example 1 and Comparative Example 1

(4) In an example of a process of the disclosure herein, a fiber-composite plastic with a matrix of polyphenylene sulfide and with exposed carbon fibers was irradiated with 300 pulses in inventive example 1 by a UV laser with energy 0.12 J/cm.sup.2 per pulse and pulse duration 20 ns in a region of exposed fibers. In comparative example 1, a fiber-composite plastic with an epoxy matrix with exposed carbon fibers was irradiated in the same manner.

(5) FIG. 1 shows a micrograph of irradiated fibers after the irradiation in inventive example 1, and FIG. 2 shows a micrograph of irradiated fibers after irradiation in comparative example 1. As can be seen from the figures, a to some extent globular nanostructure produced from the matrix material becomes attached to the fibers in inventive example 1 as a result of the irradiation of the sulfur-containing matrix.

(6) This nanostructuring on the fibers can also be seen clearly in the cross-sectional depictions in FIGS. 3 and 4.

Inventive Example 2 and Comparative Example 2

(7) The process carried out in inventive example 2 was as in inventive example 1, except that irradiation was carried out with 100 pulses (accumulated 12 J/cm.sup.2). Comparison with inventive example 1 reveals a moderate nanostructure, as can be seen in FIG. 5.

(8) The process carried out in comparative example 2 was as in inventive example 1, except that irradiation was carried out with 10 pulses (accumulated 1.2 J/cm.sup.2). No nanostructure is obtained here, as can be seen in FIG. 6.

Inventive Example 3 and Comparative Example 3

(9) The process carried out in inventive example 3 was as in inventive example 1, except that irradiation was carried out with 300 pulses (accumulated 26 J/cm.sup.2) and that the irradiation used an IR laser with wavelength 1064 nm. Comparison with inventive example 1 reveals a slight nanostructure, as can be seen in FIG. 7.

(10) Comparative example 3 corresponds to inventive example 3, except that the irradiation was carried out with 1 pulse of 27 J/cm.sup.2. Comparison with inventive example 3 clearly reveals fiber damage, as can be seen in FIG. 8.

(11) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a”, “an” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.