N ND & TECH R.I.C Il' MMlSll| |«imSiii ^ Innovative Uses of Polymers Polymers are used in almost every medical implant, for example, pacemakers, shunts, and total joint replacements, as well as in dental restoratives. The Polymers Division seeks to build on its strong program in dental restorative materials and orthopaedic devices with new programs in tissue engineering where innovative uses of polymers and biological products hold promise for regeneration and repair of human organs and tissues. Courtesy of Andrew J. Lovinger, (Division of Materials Research) Chair, NSF Macromolecular Working Group. This image was reproduced from the NSF Report of the Workshop on Interdisciplinary Macromolecular Science and Engineering, 1998. UNITED STATES DEPARTMENT OF COMMERCE MATEP' William M. Daley, US Secretary TECHNOLOGY ADMINISTRATION Gary R. Bachula, Under Secretary for Technology NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY Raymond G. Kammer, Director LABORATORY POLYMERS 1998 PROGRAMS AND ACCOMPLISHMENTS Bruno M. Fanconi, Acting Chief Donald L. Hunston, Acting Deputy NISTIR 6249 January 1999 TABLE OF CONTENTS EXECUTIVE SUMMARY vi TECHNICAL ACTIVITIES 1.1 ELECTRONIC PACKAGING, INTERCONNECTION AND ASSEMBLY PROGRAM Overview 1.1 FY-98 Significant Accomplishments 1.2 Measurements of Hygrothermal Expansion of Polymer Thin Films 1.3 Characterization of Polymer Films and Composites by Dielectric Techiques 1.4 Dielectric Measurements of Thin Films from DC to 1 GHz 1.8 Measurement of the Thermal Properties of Polymer Thin Films 1.9 Surface Roughness as Measured by Total-reflection X-ray Fluorences 1.11 Polymer Precursors for Inorganic Low-k Diectrics for Integrated Circuitry 1.12 Confinement Effects on Polymer Thin Film T and Morphology 1.14 g Polymer Ultra-Thin Films - CTE and Viscoelastic Properties 1.16 Measuring Polymer Mobility near Solid Surfaces 1.17 Novel Underfill Materials and Underfill Flow Modeling 1.19 Residual Stress in Polymer Films Adhered to Silicon Substrates 1.20 POLYMER BLENDS AND PROCESSING PROGRAM Overview 2.1 FY-98 Significant Accomplishments 2.2 Phase Behavior in Polymer Blends 2.3 Mixing and Structure Formation Under Shear Flow 2.8 Interfaces in Immiscible Multiphase Systems 2. 12 Phase Behavior in Polyolefin Blends 2. 14 In-Line Optical Characterization of Polymer Extrusion and Blend Morphology .... 2.16 Fluorescence, Dielectrics and Ultrasonics Monitoring for Polymer Processing 2. 18 Theory for Phase Separation and Transport in Polymer Liquides 2.21 Microstructure and Dynamics of Heterogeneous Materials 2.25 Polymer-Filler Interactions 2.29 Phase Separated Polymer Blend Coatings and Thin Films 2.33 Characterization of Dendrimers with Polymers, Metals, and Small Molecules 2.36 Polymer Solutions 2.42 Polymer Blends and Processing Program Outreach 2.44 POLYMER COMPOSITES PROGRAM Overview 3.1 FY-97 Significant Accomplishments 3.2 m Liquid Composite Molding: Development of Permeability Database 3.3 Liquid Composite Molding: Development of Permeability Measurement Techniques . 3 .4 Liquid Composite Molding: Development and Verification of Process Simulation Models 3.6 Liquid Composite Molding: Development of Processing Models for Viscoelastic Flows 3.8 Liquid Composite Molding: Process Monitoring and Control 3.10 Liquid Composite Molding: Interface Sensitive Optical Fiber Sensor 3.12 Microstructure Studies: Chemical Imaging 3.13 Microstructure Studies: Improve the Utility of the Single Fiber Fragmentation Test . 3.17 Hybrid Reinforced Polymer Composites 3.20 Microstructure Studies: Performance Relationships 3.22 Microstructure Studies: Measurement of Interface Strength after High Speed Processing of Polyurethanes 3.25 Microstructure Studies: Non-destructive Characterization by Optical Coherence ... 3.27 POLYMER CHARACTERIZATION PROGRAM Overview 4.1 FY-98 Significant Accomplishments 4.2 Standard Reference Materials 4.3 Mass Spectrometry of Polymers 4.4 Characterization of Polymer Morphology by Microscopy Techniques 4.7 Characterization of Polymers by Spectroscopic Techniques 4.10 Structural Characterization of Polymers by Small Angle X-Ray Scattering 4. 12 Nonlinear Viscoelasticity of Solid Polymers 4.15 Task 1. Time-Temperature, Time-Aging Time and Time-Strain Superposition below the Glass Transition 4.16 Physical Aging and Structural Recovery in Polymers 4.18 Task 1. Dilatometric Investigation of the Structural Recovery of Polymer Glasses 4.18 Task 2. The Viscoelastic Response of Industrial Materials 4.21 Task 3. Effects of Structural Recovery on Modulated and Dynamic Thermal Measurements 4.23 Failure in Polymers and Adhesives 4.25 Task 1. The Effect of Strain Rate on the Mechanical Properties of Adhesive Bonds 4.26 Task 2. Hygrothermal Aging Studies of a of Commercial Structural Adhesive 4.27 Task 3. Measurement of Craze Initiation and Growth in Polymers 4.28 Rheological Characterization of Polymer Dynamics 4.29 Task 1. Develop a Nonlinear Fluid Standard 4.30 Task 2. Viscoelastic Constitutive Model for the Creep Behavior of Poly- urethane Foams 4.32 Task 3. Melt and Solutin Nonlinear Rheology 4.33 IV Calorimetric Measurement of the Glass Transition in Nano-scale Confined Geometries 4.34 Theory and Modeling of the Ten Polymer Phase Transitions 4.35 DENTAL AND MEDICAL MATERIALS PROGRAM Overview 5.1 FY-98 Significant Accomplishments 5.2 Dental Resins Based on Fluorinated Monomers and Oligomers 5.3 Dental Composites with Improved Interfaces 5.7 Improved Adhesive Systems for Bonding to Tooth Structure 5.10 Bioactive Polymeric Dental Materials with Remineralization Potential Based on Amorphous Calcium Phosphate 5.12 Cure Monitoring of Dental and Medical Resins by Fluorescence Spectroscopy 5.14 Support for the Biomaterials Integrated Products Industries 5.17 OTHER PROJECTS Development and Utilization of Test Methods for Qualification of Passport Laminates 6.1 DIVISION MANAGEMENT 7.1 RESEARCH STAFF 8.1 APPENDIX NIST Organization Chart 9.1 MSEL Organization Chart 10.1 Polymers Division Organization Chart 11.1 Certain commercial materials and equipment are identified in this report in order to specify adequately the experimental procedures. In no case does such identification imply recommendation or endorsement by the National Institute of Standards and Technology (NIST) nor does it imply necessarily the best available for the purpose. v EXECUTIVE SUMMARY This report, covering the technical activities of the Polymers Division in fiscal year 1998, is organized according to the major programs of the Division. Each program description includes an overview that describes the motivation for the individual projects, selected accomplishments that we wish to emphasize and project summaries. Relevant publications are referenced for the reader who wants further information. The Polymers Division provides standards, measurement methods, data and concepts of polymer behavior for the U.S. polymers industries and business enterprises that use polymers in products and services. The Division looks at trends in the production, processing and use of polymers in deciding areas of work. The following stimulates the current focus on electronic applications of polymers, polymer blends and processing, polymer composites, dental and medical materials, and characterization of polymer structure and properties. • New catalysts systems give polymer producers the ability to control molecular architectures to levels heretofore unknown. The Division creates new tools based on recent advancements in mass spectrometry to characterize molecular structure. • Most commercial polymeric materials are not single component systems, but mixtures of several polymers along with additives or fillers that improve processibility, enhance properties and/or improve long term performance. As new market opportunities and increased competitive pressures arise from advances in polymer synthesis and the precise control material components, there are increasing demands on polymer suppliers and processors for multifunctional materials with improved performance and ease of production. Current work to provide the measurement tools and knowledge base required in response to these demands includes on-line characterization of temperature and phase behavior, shear effects on phase behavior, morphology and dispersion, influence of compatibilizers and fillers, and control of interfacial interactions. • The full utilization of fiber reinforced polymers for structural applications is limited by the lack of rapid, reliable, cost-effective fabrication methods and the poor understanding of and predictive capability for long-term performance. Methods are developed to monitor, model and control events that occur during composite fabrication by liquid molding technology and other new fabrication techniques. Test methods are developed for assessing important characteristics such as the resin/fiber interfacial adhesion and the subsequent degradation of this adhesion resulting from fluid attack, particularly moisture. • Another trend is the increasing importance of polymers in the form of thin films. The microelectronics industry is one example of where polymeric films are used as photoresists, dielectric insulators and encapsulants. The Division develops x-ray and neutron reflectivity techniques to measure the properties of the submicron thick polymer films that are necessary for continued development in the field. vi • Health care professionals increasingly use polymeric materials to replace diseased structures. The Division provides basic materials science, test methods and standards for the