# Mechanical Properties of Sandwich Composites Reinforced by Nanoclas: An Overview
## 5 Conclusions  
Literature presents a considerable number of studies reporting the advances achieved in the field of sandwich materials, in order to respond to the countless industrial applications that we have witnessed \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Year** & **Author** & \begin{tabular}{c} **Sandwich** \\ **(Skin/Core)** \\ \end{tabular} & \
\begin{tabular}{c} **Type of** \\ **Nanoclay** \\ \end{tabular} &
\begin{tabular}{c} **Wt\% of** \\ **Nanoclay** \\ \end{tabular} & **Improvements** & **Ref.** \\ \hline
2010 & [PERSON] et al. & Vinyl ester/foam & Cloisite® 30B & 1.25 to 2.5 & Storage modulus, loss factor and loss modulus increased for higher contents of NC *. & [31] \\ \hline
2012 & Anbusagar & Glass fiber/PS & Cloisite® Na+ & 2 to 6 & 4 wt\% of NC * promoted the highest flexural properties and 6 wt\% increased the impact strength by around 50\%. & [32] \\ \hline
2013 & [PERSON] et al. & Glass fiber/balsa & Cloisite® 30B & 3 &
\begin{tabular}{c} Lower displacements (34.4\%) and higher elastic recuperation (45.4\%) occurred for sandwich-ches with resin nano-enhan-ced. \\ Residual neural strength increased with the introduc-ion of NC *. \\ \end{tabular} & [12] \\ \hline
2014 & Anbusagar & Glass fiber/jute & Na+ &
\begin{tabular}{c} The highest flexural properties were \\ obtained for 4\% of NC *, while the \\ impact, hardness and water absorption \\ properties were obtained for 6\% of NC*. \\ \end{tabular} & [34] \\ \hline
2014 & [PERSON] et al. & Glass & Cloisite® 30B & 1 to 5 &
\begin{tabular}{c} Tensile strength increased about 33\% \\ when 3\% of NC* was added. Regarding \\ the flexural properties, the ben-ding \\ strength increased around 47\% when 5\% of NC* was ad-ded. Water absorption \\ decrea-sed for samples with NC *. \\ \end{tabular} & [35] \\ \hline
2015 & Anbusagar & Glass fiber/PS & Cloisite® Na+ & 0 to 4 & 4 wt\% of NC * was the best content to obtain the highest flexural properties (improve-ments about 60\% and 21\% for the flexural strength and stiff-ness, respectively) and Charyry impact strength (improve-ments around 43\%). \\ \hline
2016 & Anbu Sagar & Glass fiber/jute & Na+ & 2 to 6 &
\begin{tabular}{c} 4 wt\% of NC * was the best content to \\ obtain the highest flexural properties \\ for the flexural strength and stiffness, \\ respectively.) 6 wt\% of NC* was the best content to obtain the highest Chary \\ impact strength (improve-ments around 22.4\%) and moisture absorption of 50\% after 744 h. \\ \end{tabular} & [37] \\ \hline
2016 & Anbu Sagar & Glass fiber/PS & Na+ & 2 to 6 &
\begin{tabular}{c} 4 wt\% of NC * was the best content to \\ obtain the highest flexural properties \\ for the flexural strength and stiffness, \\ respectively.) 6 wt\% of NC* was the best content to obtain the highest Chary \\ impact strength (improve-ments around 50\%) and moisture absorption of 72\% after 744 h. \\ \end{tabular} & [37] \\ \hline
2018 & Anbusagar & Glass fiber/PU & Na+ & 4 wt\% of NC * increased the load carrying capacity around 114\% higher than for control samples. Decreased the delle-colon damage during the im-pact. & [38] \\  & et al. & foam & Montmorillonite & After impact, flexural strength and bending stiffness increased 23\% and 40\%, res-pedtively. & [38] \\ \hline
2019 & Anbusagar & Glass fiber/jute &
\begin{tabular}{c} Organically \\ modified \\ Montmorillonite \\ \end{tabular} & 0 to 6 & 6 wt\% of NC * showed a decrease in damage area close to 19.5\%, for low energies and 15.5\% for medium energies. & [39] \\  & et al. & fiber & Montmorillonite & The damage tolerance capabi-lity increased about 3.5 times. & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Cont. in recent years. In order to increase the mechanical performance of these materials, nanoclays is suggested in the bibliography as the most popular nano-reinforcements for polymeric nanocomposites due their relatively high ion exchange capacity, high aspect ratio and economic advantages.