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Vacuum Photografting Technique for Polymer Surface Modification

IP.com Disclosure Number: IPCOM000120377D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 92K

Publishing Venue

IBM

Related People

Chou, NJ: AUTHOR [+4]

Abstract

Disclosed is a vacuum method for photochemically modifying the surface of non-UV transparent polymer films.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Vacuum Photografting Technique for Polymer Surface Modification

      Disclosed is a vacuum method for photochemically
modifying the surface of non-UV transparent polymer films.

      Polymer surface modification provides a means of tailoring the
physical and chemical properties of polymer interfaces while
maintaining bulk characteristics. Previously reported results of
surface modification accomplished using a solution photografting
technique may be found in (1).  The drawbacks of the solution
technique include the need to use organic solvents and the
requirement that the film upon which a graft is to be grown much be
UV transparent.  The method described herein seeks to eliminate
constraints.

      The process is to vacuum photograft unsaturated monomers from
the vapor phase onto an activated polymer surface.  The entire
process is executed in a vacuum chamber in the absence of organic
solvents.  Polymer surface activation is achieved with the
UV-generated 3nfx excited state of Benzophenone (BP).  The properties
of BP as a sensitizer are well known (2,3).  Following surface
activation, which is believed to occur as surface free radical
formation, graft polymerization of unsaturated monomers from the
vapor phase proceeds.

      This has been reduced to practice.  Its features have been
demonstrated as follows.  In a vacuum chamber specifically designed
and built for this purpose, a three-mil-thick piece of poly(ethylene
terephthalate) (PET) is mounted on a temperature-controlled plate.
The plate is at ambient temperature during sample mounting.  The
system is closed and evacuated to a pressure below 5 E(-7) Torr at a
temperature of at least 100oC (100 - 150oC typically). The PET and
sample plate are allowed to equilibrate to the chamber temperature
overnight.  Solid reservoirs of acrylamide (AM) and BP are attached
to the chamber.  By heating these solids a sufficient vapor pressure
can be attained so that the AM and BP may be introduced into the
chamber as a hot vapor.  Both the AM and the BP are heated to 100oC
and then opened to the ch...