Composite Foam made from Polymer Microspheres Reinforced with Long Fibers

Technology Description:A new technological process was developed for the synthesis of fiber-reinforced foam to overcome the limitation of the use of long fibers in low-density reinforced foams. This approach does not have viscous flow and fiber arrangement limitations that are the inherent peculiarities of existing fiber-reinforced foam technology. This novel process for making foam is based on thermoplastic expandable hollow microspheres. Dry microspheres are combined with long randomly arranged fibers or fiber webs to achieve a composite foam. This approach for fiber-reinforcement of foam should work for all types of hollow polymer microspheres both expandable and non-expandable thermoplastic and non-thermoplastic. The long fiber architecture may be woven or non-woven. The permeability of fiber network should allow for penetration of the microspheres between fibers or yarns.Applications:1) Core materials for sandwich structures that are used in a wide range of engineering applications including transportation vehicles civil infrastructure wind energy applications high-performance boats electronic circuit boards radomes with controlled CTE and recreational equipment. Foams in military or civilian aircraft where the mechanical properties and crack resistance of foam cores will be improved by fiber reinforcement. State of Development Laboratory scale. Preliminary results indicate that the foam composite with this approach can match the performance of some of the best foams commercially available. For example it compares favorably with DIAB\\\'s PVC structural foam (Divinycell®) widely used in transportation vehicles building construction and wind energy structures.