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Design and Study of Ricinoleates as processing aids and activators in rubbers…. What is RPA. Any material used at relatively low dosage levels, will improve processing characteristics without significantly affecting physical properties.
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Design and Study of Ricinoleates as processing aids and activators in rubbers…
What is RPA Any material used at relatively low dosage levels, will improve processing characteristics without significantly affecting physical properties. They also improve the physical properties such as, Elasticity, Flex life, Low temp performance and, Aid in incorporation & dispersion of pigments
What is an Activator - Increase the efficiency of cross-linking - Help in dispersing the sulphur and accelerator
Driving- FACTOR • Conventional Processing aid, petroleum based Polycyclic Aromatic Hydrocarbons (PAH) has been banned in European countries at 2009. • Stearic acid (present as activator), is a saturated fatty acid obtained from animal fat.
Car photo Driving- FACTOR ZnO Reduction • Zn can be released into the environment from rubber during production, use, and recycling of rubber goods, particularly tyres. • Harmful effect of soluble Zn-compounds to aquatic organisms. • ZnO causes a mammalian reproductive toxin • Exposure to zinc oxide in the air, result in a nervous malady called metal fume fever. • ZnS deposited on the wall of the mold, causes moldfouling.
EXPERIMENT We have tried to reduce the ZnO by using a combination of metal oxide (MgO & Ca(OH)2) of varying ratios, is mixed with CASTOR OIL under microwave heating at a set frequency (1.32GHz).
Structure of Castor oil • Mono-unsaturated, 18 carbon fatty acid (esters of 12- hydroxy-9-octadecenoicacid) • Contains Functional groups: 1.carboxylic group 2.unsaturation 3.hydroxy group
Why Castor Oil • Naturally obtained non-toxic Vegetable oil • Vegetable oil offers Lubricity • Other seed oils lack the HYDROXY Group • Due to this Hydroxy group- 1. Reactive 2. Offers xtra stability 3. High viscosity
1600C for 20mins INFERENCE : Both RX6 and RX7 haven’t cured, so we neglected both the samples.
Rheological Props(GUM cmpds) INFERENCE : Scorch time is INCREASED, While Cure time is very much DECREASED
Tests for Gum cmpds : • Hardness (ASTM D2240) • Tensile Properties (ASTM D412) • Tear Strength (ASTM D624) • Aging properties (ASTM D573)
Hardness INFERENCE : Hardness values found to decrease with our Activator compounds
TENSILE STRENGTH INFERENCE : T.S is very much lower
MAX Strain % INFERENCE : profound increase in STRAIN %
MODULUS MODULUS = Resistance to extension or stiffness INFERENCE : Modulus was found to be low
Aging Properties Aging Condition- 700C for 7 days
Tear Strength(GUM cmpds) INFERENCE : Tear Strength usually higher for our Activator Cmpds
PC Formulation Benchmarked with usual mixture, ZnO - 3 phr St Acid – 2 phr
Rheograph 1600C for 20mins
Rheograph 1600C for 20mins
Rheological Props 1600C for 20mins INFERENCE : Scorch time is INCREASED, While Cure time is very much DECREASED
Tests for C-B filled cmpds • Hardness • Tensile Strength • Tear Strength • Swelling Index • Compression Set • Flex Cracking Resistance
Hardness INFERENCE : Not much change in Hardness
Tensile Strength Aging Condition – 1000C for 22hr INFERENCE : Tensile Strength is low But % retention of our activator cmpds is high
Tear Strength Aging Condition – 1000C for 22hr INFERENCE : Tear Strength and % Retention is HIGH for our activator compounds
Swelling Index Immersed in toluene for 7 days SWELLING INDEX = (Ws – Wi)/Wi Swelling Index α 1 / Crosslink Density
Compression Set SET % = (t0 – tr) / (to - ts) × 100 INFERENCE : Set found to be lower as cross-link density is less
Flex Cracking resistance INFERENCE : profound increase in Flex-Cracking resistance
Summary • With reduced viscosity, thereby reducing mix duration with less mech generation of heat & energy consumption reqd to breakdown rubber. • Ease of handling as processing aids is in the form of pellets. • With increased scorch time(Ts2), better Processing safety. • With shorter curing cycles, we get faster productivity. • The physical props of C-B filled cmpds was similar to the control, but this was not the case in GUM cmpds.
Coupling action of Veg. oil Interacts with Rubber molecules Interacts with C-Black as its surface contains Phenol, Carboxyl, Quinone & Lactones
Why MgO & Ca(OH)2 • These were the acid acceptors playing a dual role : 1. Neutralization of acid-byproducts of vulcanization and; 2. Act as cross-linking agents forming weak ionic bonds.