Cassava Peel Film Study

Abstract. Cassava peel is one of agricultural waste that abundantly found in environment. One approach to utilize this waste is to apply it as filler in natural rubber latex. In this work, the cassava peel waste (CPW) was powdered and dispersed in alkanolamide-water dispersion system to modify its surface. The amount of fillers used was 0, 5, 10, 15, 20 and 25 phr (part per hundred rubber) and loaded in natural rubber latex (NRL) formulation system. The products then were casted by dipping method after the NRL formulation was pre-vulcanized at 70oC. The observed parameter includes crosslink density, tensile strength, tensile modulus and elongation at break. The morphology of film was studied via Scanning Electron Microscope (SEM). The results
Cassava peel waste (CPW) was obtained from cassava cracker factory in Medan, Indonesia and dried at 100 °C for 24 hours. The dried peel was milled and sieved until the size of 100 mesh was obtained. The supporting chemical substances such as potassium hydroxide (KOH), sodium hydroxide (NaOH), acetic acid (CH3COOH), calcium nitrate tetrahydrate (Ca(NO3)2.4H2O), toluene (C6H5CH3), chloroform (CHCl3), diethanolamine ((C2H4OH)2NH), sodium chloride (NaCl), diethyl eter ((C2H5)2O), methanol (CH3OH), sodium methoxide (CH3ONa), sodium sulphate (Na2SO4) were used in this study. The materials were laboratory grade (MERCK) and were purchased from CV. Multi Kreasi Bersama, Medan, Indonesia. The curatives for pre-vulcanization system of NRL consist of sulphur as crosslinking agent, zinc oxide (ZnO) as activator, zinc diethyldithiocarbamate (ZDEC) as accelerator, and antioxidant (AO). The curatives were obtained from Farten Technique (M) Sdn Bhd, Pulau Penang,
The figure shows an increasing trend with the increment of filler loading. It can be seen that NRL with 10 phr filler loading has the highest crosslink density. When the modified fillers were incorporated, the latex-CPW interaction increase due to the contribution of alkanolamide that improved interfacial adhesion between rubber matrix and filler. The crosslink network will be strengthened due to this contribution. The additional filler loading over 10 phr might lead to the deterioration of crosslink network, thus the crosslink density value decreases.
Figure 2 illustrates the similar trend with Figure 1. When modified CPW succeed in strengthening crosslink network, the tensile strength will also improve as there is a good interfacial adhesion between NRL and modified CPW. This shows that modified CPW has reinforcing effect when it was incorporated in latex matrix. The filler addition over 10 phr will result in decreasing value of tensile strength. This might be due to the occurrence of agglomeration in the latex films as it will be explained further in SEM