Filtern
Dokumenttyp
Sprache
- Englisch (26)
Schlagworte
- Introduction of functional groups (3)
- Plasma modification (3)
- Acrylic acid (2)
- Allyl alcohol (2)
- Allylamine (2)
- Aluminium (2)
- Metal-polymer systems (2)
- Peel strength (2)
- Pulsed plasma (2)
- Pulsed plasma polymerization (2)
- Reactions at polymer surfaces (2)
- Adhesion (1)
- Adhesion promoters (1)
- Adhesion promoting interlayers (1)
- Adhesion-promoting interlayers (1)
- Adhesion-promoting plasma polymer layers (1)
- Al-functional group interactions (1)
- Charcterization of homo- and copolymers (1)
- Co-polymers (1)
- Cone calorimeter (1)
- Copolymers (1)
- Flame retardance (1)
- Functional groups (1)
- Heat release (1)
- Metal-polymer composites (1)
- Plasma polymerization (1)
- Plasma polymers with functional groups (1)
- Plasma surface treatment (1)
- Plasma-initiated copolymerization (1)
- Poly(tetrafluoroethylene) (1)
- Polyamides (1)
- Polypropylene (1)
- Reactions at Polymer surfaces (1)
- r.f. pulsed plasma (1)
The peel strength of aluminium to polypropylene and poly(tetrafluoroethylene) was determined in dependence on the type and the concentration of functional groups on the polymer surface. For this purpose the polymer surface was equipped with monotype functional groups. The first method to produce monotype functionalized surfaces was an introduction of O functional groups using an oxygen plasma treatment and converting these groups to OH groups applying a wet chemical reduction. In result of this two-step treatment the hydroxyl group concentration at the polymer surface could be increased from 34 to 1014 OH groups/100 C atoms. The second method consists in the deposition of a 150 nm adhesion-promoting layer of plasmapolymers or copolymers onto the polymer surface using the pulsed plasma technique. For that purpose functional groups carrying monomers as allyl alcohol, allylamine and acrylic acid were used. Applying the plasma-initiated copolymerization and using neutral monomers like ethylene or butadiene the concentration of the functional groups was varied.
A correlation of peel strength with the ability of forming chemical interactions between Al atoms and functional groups was found: COOH > OH >> NH2 > H(CH2CH2).
Polymers synthesized with plasma techniques are very interesting materials for electronic, optic, and bio compatible applications. Thin films of plasma polymers shows a good adhesion to metals, glass, or other polymers. But the supramolecular structure, the durability, and the chemical and mechanical behavior of these polymers is poorly understood. Therefore dielectric investigations are carried out to study the dynamic behavior of the plasma polymers. As polymer system allyl alcohol/alkene is chosen to get polymers with a defined concentration of hydroxyl groups. The dielectric investigations shows several relaxation processes and a dependency of the dielectric parameters from the ratio of allyl alcohol in the polymer is observed. This results indicated that the alkene monomers were assembled continuous into the polymer matrix.
Monotype functionalizations with different types of functional groups (OH, NH2, COOH) on polypropylene and poly(tetrafluoroethylene) surfaces were synthesized using pulsed plasma-initiated homo- or copolymerization of functional group-carrying monomers. The maximum concentrations of functional groups were 31 OH, 18 NH2 or 24 COOH groups per 100 C atoms using allyl alcohol, allylamine or acrylic acid respectively as the monomer. The measured peel strengths of aluminium deposits increased linearly with the concentration of functional groups. Near the maximum concentration of OH (>27 OH/100 C atoms) or at moderate concentrations of COOH groups (>10 COOH/100 C atoms), constant (maximum) peel strengths were measured due to the mechanical collapse of one component in the composite (cohesive failure). Interface failures in Al-PP composites were found with COOH, NH2 and OH groups and cohesive failures were seen when higher concentrations of COOH groups were applied (>10 COOH/100 C atoms).