Terrill Ed.,Akron Rubber Development Laboratory, Inc
Rubber World | Year: 2011
In summary, the following general conclusions were found: • First, all five compounds were prepared unfilled and compounded to a very high crosslink density. At very high crosslink density, the peroxide based compounds exhibited better ultimate properties than the sulfur based compound. A clear explanation is under further investigation. • Second, modulus was directly related to crosslink density, irrespective of crosslink type. • Third, because of the high crosslink density across the samples investigated, the distribution of molecular weight between crosslinks was not significantly different in this series of compounds and was not detectably different using the Time-Domain NMR technique. • Fourth, compounds with bulky crosslink structures were more hysteretic (higher loss modulus and tangent delta) under dynamic mechanical deformation. • Last, compounds with thermally labile crosslinks were more affected by high temperature creep and compression set, as in the case of ZMDA-peroxide and SEV compounds. At very high crosslink density, as in this case, differences in crosslink type and the effect on cured physical properties are too narrow to accurately distinguish. A subsequent study should be undertaken to explore compounds at lower crosslink density more consistent with practical formulations.
Hershberger N.,Akron Rubber Development Laboratory, Inc
Rubber World | Year: 2013
Five different accelerators are evaluated at different loadings to characterize their effect on binding the free sulfur in vulcanized vegetable oil (VVO). The accelerators evaluated were TMTD (tetramethylthiuram disulfide), ZDMC (zinc dimethyldithiocarbamate), MBTS (2,2'-dibenzothiazole disulfide), TBBS (N-tertbutyl-2-benzothiazolesulfenamide) and DPG (N,N'-diphenylguanidine). Each accelerator was added in a VVO compound at 1.0 and 2.0 phr to evaluate the accelerator and loading effects on heat aging properties. Once the VVO was synthesized, it was removed from the beaker and put on an aluminum tray to cool. All VVOs rested for at least 72 hours before being mixed in a rubber compound or tested. All accelerated VVOs reacted faster than the control VVO without accelerators. The percent free sulfur was lower in the VVO compounds with 1.0 phr ZDMC, 2.0 phr TMTD, 2.0 phr ZDMC and 2.0 phr DPG than the control compound with no acceleration.
Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase I | Award Amount: 69.98K | Year: 2008
Developing a robust and accurate test for the detection of malaria continues to be an elusive challenge.1,2 The objective of this proposal is to develop an innovative approach to the diagnosis of malaria that is very specific and sensitive for detecting the presence of malaria parasites in red blood cells (RBC). This approach could potentially be more effective than the current microscopic and rapid detection tests that seem to have issues with both false positives and negatives. A novel approach is necessary to explore other untapped avenues and identify a new methodology to achieve this objective. As ARDL, Inc.’s newly established division, ARDL Pharmaceutical Services Lab is uniquely positioned to address this objective. Phase I would consist of characterization of extracts of standard RBC that contain the malaria parasite, Plasmodium. Phase II of the proposal would then be focused on translating the results from the Phase I proof of principle demonstration into a robust method with the ultimate goal to develop a simple, low cost, modular type test that could be used for diagnostic purposes in remote areas of the world.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 99.50K | Year: 2002
"Sandwich structural designs are the most weight efficient concepts for stability-critical components such as control surfaces. The objective of this proposal is to demonstrate the feasibility of producing honeycomb sandwich structure using a unique DoubleWalled Honeycomb design. This new ARDL honeycomb design is called Hexagonal Double walled structure or "HexD" This is depicted in Figure 1.HexD honeycomb core exhibits a unique cell structure. This design promises a higher stiffness to weight ratio, barrier resistance, and higher impact resistance. Higher stiffness has already been demonstrated using finite element analysis and prototypetesting. Figure 2 illustrates the significance of the using HexD over a common regular honeycomb in almost all the aspects of its usage as a control surface.The primary function of the face sheets is to provide the required bending and in-plane shear stiffness, and to carry the axial, bending, and in-plane shear loading. The primary function of the core is to stabilize the facings and carry most of the shearloads through the thickness. In order to perform this function the core must be as rigid and as light as possible. HexD performs these functions in a rather unique manner by having 86% more bond lengths and twice the walls.The primary structural role of the adhesive, which is the face/core interface in sandwich construction, is to transfer shear stresses between faces and core. This condition stabi
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 750.00K | Year: 2003
Sandwich structural designs are the most weight efficient concepts for stability-critical components such as control surfaces. The objective of Phase I of this study was to demonstrate the feasibility of producing a honeycomb sandwich structure using aunique Double Wall Honeycomb design. This new ARDL honeycomb design is called Hexagonal Double wall structure or