Phenol formaldehyde resol resins with plant-based tannin for composite laminate applications
The use of phenol and formaldehyde in preparing resole resins had sparked some environmental concerns. This study investigated the feasibility of substituting or minimising the use of phenols and formaldehyde in the preparation of phenol formaldehyde resins by adding dissolved tannin into the for...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2021
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/92944/1/FK%202021%2082%20-IR.1.pdf |
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| Summary: | The use of phenol and formaldehyde in preparing resole resins had sparked some
environmental concerns. This study investigated the feasibility of substituting or
minimising the use of phenols and formaldehyde in the preparation of phenol
formaldehyde resins by adding dissolved tannin into the formulations. The objectives
of the research include assessing the effects of varying the molar ratio of phenol and
formaldehyde in the preparation of phenol formaldehyde resins, evaluating the
effects of minimising the use of phenol and formaldehyde and replacing it with
dissolved tannin in the resins’ formulation, and analysing the curing kinetics of resins
and profiling the heat transfer behaviour of the composite laminate using a
computational fluid dynamics software. The analyses performed in this research
cover the rheological, physical, thermal, chemical and mechanical properties as well
as the microscopic imaging of the produced resins and the composite laminates. The
phenol formaldehyde (PF) resin shows a shear thickening behaviour at all
temperature sets, i.e., 40oC, 60oC, 80oC and 100oC. Water in formalin reduces the
flexural and tensile properties of the PF composite laminates by 97.0% and 67.8%,
respectively. The dissolved tannin reduces the amount of PF used by 20.0 % and
improves the flexural and tensile properties of the PF composite laminates by 26.0%
and 8.8%, respectively. Some reduction in the thermal properties of the resins were
noted whilst the Ea values for both formulations were similar. Autocatalytic model
can be used to represent the curing kinetics when the degree of cure is lower than 0.4
and 0.5 whilst the nth order model can be used to represent the curing kinetics when
the degree of cure is higher than or equal to 0.4 and 0.5 for PF and dissolved tannin
phenol formaldehyde (DTPF) resin, respectively. During curing the laminate, the
heat was dissipated from the edges of the composite to the centre, while, during post
curing, the heat was dispersed from the centre to the edges of the composite
laminate. This study shows the feasibility of reducing the content of PF in the
formulation of PF by adding dissolved tannin to the formulations. It is good to note
that with the addition of dissolved tannin, the mechanical integrity of the composite
laminate was improved. |
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