Synthesis and characterization of unsaturated polyester resin- clay nanocomposite

• Main Author: Abobo, Ibarra Miguel D.
• Format: text
• Language: English
• Published: Animo Repository 2019
• Subjects: Clay; Polymerization; Montmorillonite; Chemistry; Physical Sciences and Mathematics; Polymer Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/5838; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=12676&context=etd_masteral
• Institution: De La Salle University

Unsaturated polyester resins (UPR) are a class of thermosetting resins that are produced via the condensation (polyesterification) reaction between unsaturated acids or anhydrides and diols in the presence or absence of diacids. They can be cured via free radical polymerization with a crosslinker such as styrene monomer. They can be mixed with a variety of fillers for specialty applications. One such filler is the montmorillonite clay. Montmorillonite, a phyllosilicate clay, is a usual inorganic additive of choice for many polymers, resulting in the preparation of organic-inorganic nanocomposite with enhanced properties compared to that of the bare polymer. This study was focused on the evaluation of two types of clay as the additives to the UPR as the matrix material: the unsilylated and the silylated montmorillonite (MMT) clays. The UPR used was a commercial one, Polycol 03-027PL, using methyl ethyl ketone peroxide (MEKP) as a curing agent/free radical initiator. The unsilylated MMT additive results in most usual type of clay-based polymer nanocomposites, though may result in well-dispersed clay fillers within the polymeric matric, do not form strong covalent attraction with the polymer. The silylated MMT clay is modified such that it has a functional group that may react with the UPR matrix resulting in covalently bonded attraction between the clay and the UPR matrix. To prepare the silylated clay additive, first, the surface modified montmorillonite was synthesized via a silylation reaction using vinyltrimethoxy silane (VTMS) in hexane and was monitored using Fourier transformation-infrared spectroscopy (FT-IR). Next, varying amounts (1%, 3%, 5% and 10% by mass) of the silylated and unsilylated clay fillers were added to the UPR. For each treatment, six dog bone-shaped samples were prepared in a silicone mold and were cured at 30 ± 1 °C. they were then post-cured in an oven at 70 ± 1 °C. the thickness and width of the samples were measured to obtain their cross-sectional area. The max