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Abstract:
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The aim of the investigation is to develop new high performance
adhesive systems based on neoprene-phenolic blends. Initially the effect of
addition of all possible ingredients like fillers, adhesion promoters, curing
agents and their optimum compositions to neoprene solution is
investigated. The phenolic resin used is a copolymer of phenol-cardanolformaldehyde
prepared in the laboratory. The optimum ratio between
phenol and cardanol that gives the maximum bond strength in metal-metal,
rubber-rubber and rubber-metal specimens has been identified.
Further the ratio between total phenols and formaldehyde is also
optimised. The above adhesive system is further modified by the addition
of epoxidized phenolic novolacs. For this purpose, phenolic novolac resins
are prepared in different stoichiometric ratios and are subsequently
epoxidized. The effectiveness of the adhesive for bonding different metal
and rubber substrates is another part of the study. To study the ageing
behaviour, different bonded specimens are exposed to high temperature,
hot water and salt water and adhesive properties have been evaluated. The
synthesized resins have been characterized by FTIR , HNMR spectroscopy.
The molecular weights of the resins have been obtained by GPC.
Thermogravimetric analysis and differential scanning calorimetry are used
to study the thermal properties. The fractured surface analysis is studied by
scanning electron microscopy. The study has brought to light the influence
of phenol/ formaldehyde stoichiometric ratio, addition of cardanol (a
renewable resource), adhesion promoters and suitability of the adhesive for
different substrates and the age resistance of adhesive joints among other
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