The SEM folder contains images of the cross sections of the CNC foams which visulalize the macroporous structure. Those images were used to estimate the macropores sizes. It also contains HRSEM pictures of the foam wall were it can be seen the foam wall thickness. The images can be opened with any image application. There are also some txt files containing the technical details. The AFM folder contains images of the CNC particles and they were used to estimate their diameter and length. The images can be opened with an AFM software such as Nanoscope Analysis. The DSC folder contains the specific heat capacity data of the CNC foams in xlsx file. The XRD folder contains the 2D XRD patterns that were used to determine the Herman's parameter. It also contains the 1D diffractograms that were used to calculate the crystallinity index. The image files can be opened with any image application and the txt files can be opened by notepad or be inserted into origin. The Humidity Chamber folder contains the gravimetric moisture uptake data in txt files. The conditioning cycles were always 6 hours. The first drying step was at 313 K and 20% RH. Then the rest of the data contain the moisture uptake at 20%, 35%, 50%, 65% and 80% at 295 K and each cycle was 6 hrs. The data used to determine the moisture uptake was the average of the last 1 hr. The files are txt format. The Humidifier folder contains the relative humidity and temperature data during the thermal conductivity measurements. Correlating the time and day of the thermal conductivity experiments from the Hot Disk folder it results in the corresponding humidity and temperature conditions. The files are xlsx format. The BET folder contains the nitrogen sorption experiments that were done to estimate the BET surface area and the BJH pore volume in txt formats. The Hot Disk folder it contains the thermal conductivity measurements from the Hot Disk instrument. The sample name indicates which CNC foam sample was measured in correlation to the CNC dispersion concentration. The measurements were always performed in the same sequence, 0% RH (which never actually 0 but around 5-7% RH which was the lowest we could get), 20% RH, 35% RH, 50% RH, 65% RH and 80% RH at 295 K. For each measurement condition 5 independent measurements were prformed and averaged. The files are xlsx format.