Intro/Motivation Polymer Bonded Explosives XTX 8004 (80 wt% PETN-20 wt% PDMS) Mock Energetic Composite Fabrication Procedure Engin C. Sengezer Department of Aerospace and Ocean Engineering, Virginia Tech, Blacksburg VA AOE 3054 Experimental Methods
Intro/Motivation ALUMINUM MOLDs 2
Intro/Motivation STEP 1 Measure the total weight of PDMS part A and B required corresponding to X wt% particulate (sugar) amount to fabricate tension, compression, compact tension and Charpy mock energetic composites using the EXCEL sheet provided Repeat step 1 for your two different particulate weight concentrations FIRST BATCH PDMS wt% 20 Sugar wt% 80 SECOND BATCH PDMS wt% 80 Sugar wt% 20 PDMS weight [g] 29.42 Sugar weight [g] 117.7 Weight ratio [g] 4 PDMS weight [g] 120.6 Sugar weight [g] 30.16 Weight ratio 0.25 PDMS volume [ml] 28.56 Sugar volume [ml] 74 Volume ratio 2.591 Sugar vol % 72.15 PDMS volume [ml] 117.1 Sugar volume [ml] 18.97 Volume ratio 0.162 Sugar vol % 13.94 3
Intro/Motivation STEP 2 Turn on the scale (0/I) Change unit to grams (Unit button) Place the filter flask on the scale Tare (zero) the scale ( T button) 4
Intro/Motivation STEP 3 Pour the required PDMS Part A into your first filter flask as your FIRST BATCH 10 Part A vs 1 Part B by weight PDMS part A 5
Intro/Motivation STEP 4 Pour the required PDMS Part B into your first filter flask to finalize your FIRST BATCH Repeat 2-4 for your SECOND BATCH 10 Part A vs 1 Part B by weight PDMS Part B 6
Intro/Motivation STEP 5 FIRST BATCH SECOND BATCH Place magnetic stirring bars into your batches Stir at a speed of 3 at 40 Celcius for 5 mins Increase the speed to 4 after at 40 Celcius Stir 5 more mins 7
Intro/Motivation STEP 5 alternative Normal beaker can be used instead of filter flask. 8
Intro/Motivation STEP 6 Degassing your PDMS mixture within filter flasks to get rid bubbles for 30 mins or less This configuration attached to vacuum pump will be provided TEAM A 1 st Batch 2 nd Batch TEAM B 1 st Batch Do not degas any polymer more than 100 ml using filter flask 2 nd Batch 9
Intro/Motivation STEP 6 continues T 0 T 1 After 30 mins T 2 10
Intro/Motivation STEP 7 Take your filter flasks 1 st Batch 2 nd Batch 11
Intro/Motivation STEP 7 Alternative Do not degas any polymer more than 150 ml using 1000 ml beaker Degassing can be done in this chamber. 1 st Batch 2 nd Batch 12
Intro/Motivation STEP 8 Following STEP 1, pour the required particulate (sugar ) into your beaker for 1 st BATCH Following STEP 1, pour the required particulate (sugar ) into your beaker for 2 nd BATCH 13
Intro/Motivation STEP 8 continues 2 nd Batch TEAM A 1 st Batch PDMS 20 wt% Particulate 80 wt% (sugar) PDMS 80 wt% Particulate 20 wt% (sugar) 14
Intro/Motivation STEP 9 Pour at most 2 table spoon of particulates (sugar crystals) at a time into your corresponding batches Coat the particulates (sugar crystals) by stirring with lab spoon slowly Follow Step 5 for only 5 mins at a speed 3 at 40 Celcius for particulate wt% 40 TEAM A 80/20 wt% Sugar-PDMS 20/80 wt% Sugar-PDMS 15
Intro/Motivation STEP 10 Spray mold release agent into your aluminum molds This step will be done before each team arrives 16
Intro/Motivation STEP 11 Cast particulate composite mixtures into aluminum molds and cure for 1 hour at 100 17
Intro/Motivation STEP 12 Kapton film is used to mask the molds for particulate weight concentration > 80 wt% 90/10 wt% Sugar-PDMS 18
Intro/Motivation STEP 12 19
Intro/Motivation Compact Tension Sugar PDMS Mock Energetics a) b) 30 wt% 40 wt% 80 wt% 90 wt% 0 wt% 10 wt% 20 wt% 50 wt% 60 wt% 70 wt% c) d) 70 wt% 80 wt% 90 wt% 0 wt% 10 wt% 20 wt% 30 wt% 40 wt% 0 wt% 10 wt% 20 wt% 30 wt% 40 wt% 50 wt% 60 wt% As-produced Compact Tension mock energetics: Particulate wt% is 0-90 20
Intro/Motivation Dogbone Sugar PDMS Mock Energetics a) b) 40 wt% 90 wt% 30 wt% 20 wt% 10 wt% 80 wt% 70 wt% 60 wt% 0 wt% 50 wt% As-produced dogbone mock energetics: Particulate wt% is 0-90 21
Intro/Motivation Charpy Sugar PDMS Mock Energetics a) b) 60 wt% 90 wt% 50 wt% 80 wt% 40 wt% 70 wt% 30 wt% 20 wt% 10 wt% 0 wt% As-produced Charpy mock energetics: Particulate wt% is 0-90 22
Intro/Motivation Compression Sugar PDMS Mock Energetics 50 wt% 60 wt% 70 wt% 80 wt% 90 wt% 0 wt% 10 wt% 20 wt% 30 wt% 40 wt% As-produced compression mock energetics: Particulate wt% is 0-90 23