Grantee Research Project Results
Final Report: Development of an Environmentally Benign Primer for Metal Adhesive Bonding
EPA Contract Number: 68D98141Title: Development of an Environmentally Benign Primer for Metal Adhesive Bonding
Investigators: Zheng, Haixing
Small Business: Chemat Technology Inc.
EPA Contact:
Phase: I
Project Period: September 1, 1998 through March 1, 1999
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (1998) RFA Text | Recipients Lists
Research Category: SBIR - Pollution Prevention , Nanotechnology , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Description:
The purpose of this research is to develop an Environmentally Benign Primer for metal adhesive bonding.In this research a series of water based systems for adhesive bonding were developed .Whereas our sol-gel solution will be reacted with water borne functional polymers such as epoxy resins.
The purpose of this project is also to identify and incorporate non- chromated corrosion inhibitors as well as corresponding metal oxides which will hydrolyze and polycondensate with aluminum oxides so that these metal ions are homogeneously distributed on molecular level.
The efforts in this project are aimed to develop and identify a non chromated environmentally benign primer for Metal Adhesive Bonding and formulation of non-surface treatment primers for adhesive bonding which are expected to possess many advantages over traditional primers.
Many industries are willing to adopt new environmentally-friendly primers. This is the essence for commercialization of the primer that has been developed as a result of this feasibility research..
The purpose of this research is also to study the sol-gel processing for coatings and testing by methods such as lap shear test, wedge crack test for adhesive bonding for titanium, aluminum and steel alloys.
Brief description of the research carried out and results of research:
The current results for developing a primer for adhesive bonding of metals includes formulation and evaluation of new innovative primers for adhesive bonding of metals.
A number of sol-gel based adhesive bonding primers with new adhesion promoting additives were developed and tested in detail in the environmentally benign primer for metal adhesive bonding.
The adhesion bonding systems were formulated in a number of viable formulations and were evaluated on adhesive bonding substrates.
The formulations were tested by tee-peel, wedge crack test methods on a number of metallic substrates.
Polyblends of various epoxy resins were evaluated to study the impact of various molecular weight resins on adhesive bonding performance.
Impact of resin systems known to impart toughness, water resistance, flexibility, high temperature resistance were evaluated .
Resin modifier systems were tested in the adhesive bonding formula for the purpose of studying the adhesive bonding system.
Impact of surface preparation methods on aluminum were investigated with respect to adhesion bonding phenomenon.
The performance of adhesive bonding system combined with sol gel process was compared to some existing market primers.
Impact of inhibitors and surface adhesive film formers were evaluated.
Polyblends, various silane adhesion promoters were evaluated in conjunction with new primer for adhesive bonding of metals.
Summary/Accomplishments (Outputs/Outcomes):
The findings of the research can be summarized as follows:Sol gel based adhesive bonding system was developed that is non chromated,
and is a minimal to non VOC environmentally benign system.
Extensive studies were made on this system to fine tune a water resistant adhesive bonding system.
Adhesion promoter additives were evaluated and selected for use in adhesion bonding primer. Number of adhesive systems were selected as adhesion promoting additives.
Polyblends of bisphenol A epoxy resins to impart physical characteristics of material toughness, temperature resistance and chemical resistance were evaluated and resin combinations were selected.
Extensive testing was carried out on tee-peel and wedge crack testing of selected adhesive bonding primer systems. It was found that PVA and formladehyde adhesion promoters in conjunction with polyblend of epoxy resins system gave a significant improvement in adhesive bonding.
Impact of resin system known to impart toughness water resistance, high temperature resistance were studied and polyblends imparting toughness, chemical and heat resistance were selected.
Surface prep methods evaluations on acid etch, grit blast techniques were made. It was found that grit blast method was giving the most adhesive bonding improvement.
It was found that adhesive bonding primer premixed with the sol gel system has better adhesion than the adhesive bonding primer applied on top of metal surface treated with the sol gel process.
Impact of inhibitors such as carboxy benzotriazoles and benzortriazoles on film formation and adhesion promotion were tested. Inhibitor systems of carboxybenzotriazole, benzotriazole were identified for the adhesion bonding system.
Formulations were made with water resistant resins such as polybutadiene to improve bonding strength after high humidity tests.
Commercialization Potential:
The sol-gel based non-surface pretreatment primers for adhesive bonding are expected to possess many advantages, mainly that of environmentally benign nature and ease of application. Many industries are willing or are being forced to using environmentally benign primers.
Industries that can have commercial use for the primers include aerospace, construction, chemical and petrochemical industries.
The products that can have potential application for this primer include, airframe and skin sheet in aerospace industry, panels and laminates in construction industry, brake shoe bonding in automotive industry, circuit boards in electronics, baseball bats in sporting goods.
Journal Articles:
No journal articles submitted with this report: View all 1 publications for this projectSupplemental Keywords:
Scientific Discipline, Toxics, Sustainable Industry/Business, Chemical Engineering, cleaner production/pollution prevention, Environmental Chemistry, Analytical Chemistry, Civil/Environmental Engineering, Chemistry and Materials Science, 33/50, Environmental Engineering, chromium & chromium compounds, waste minimization, waste reduction, cleaner production, environmentally conscious manufacturing, green design, metal adhesive, clean technology, water-based coatings, engineering, water based primer, innovative technology, sol-gel coating, environmentally benign alternative, adhesives, pollution prevention, alternative chrome plating, corrosion inhibitorsSBIR Phase II:
Development of an Environmentally Benign Primer for Metal Adhesive Bonding | 1998 Progress Report | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.