No abstract

Wood polymer nano composites (WPnC) based on nano-SiO2 were prepared by the impregnation of nano-SiO2 and melamine formaldehyde-furfuryl alcohol copolymer. The objectives of this research were to analyze the effect of impregnation of nano-SiO2 and Melamine Formaldehyde Furfuryl Alcohol (MFFA) copolymers on the physical properties of jabon wood and to characterize treated jabon wood. Impregnation method improved the physical properties of jabon wood. Density of jabon become 0.56 g/cm3, weight percent gain (WPG) is 68.34%, Anti-Swelling Efficiency (ASE) is 46.66%, bulking effect (BE) is 7.55%, water uptake (WU) is 75.49%. WPnC composites were characterized by Fourier Transform Infrared Spectroscopy (FTIR), XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), and SEM-EDX (Energy-dispersive X-ray Spectroscopy). FTIR results showed that the Si-O-Si asymmetric stretching vibration hand slighty shifts toward a higher wave number. It indicated a reaction between nano-SiO2 and wood. XRD studies indicated a decrease in crystallinity of the composites. SEM images observed distribution of nano SiO2 in the composites.

Corncobs have a high level of cellulose hence making it suitable to be used as the main ingredient in making hydrogels. Hydrogel are crosslinked polymers capable of absorbing water hundreds to thousands of times their dry weight, but are insoluble in water due to the three-dimensional structure of the polymer network. Hydrogel can be synthesized using corncobs cellulose and acrylate-acrylamide with chemical crosslinking methods. This study aims to determine the effect of adding corncobs cellulose and acrylate-acrylamide on hydrogel ability to swelling ratio, gel fraction and texture analysis. Nanohydrogel were synthesized by cellulose concentration by 5-25% while acrylamide was varied 10,12 and 16 %. The treatment concentration ratio of nanocellulose solution to acrylamide also showed a significantly different effect at 5% level. The optimum hydrogel synthesis was the treatment of 10 % cellulose ratio and 16% acrylamide ratio which has a swelling ability of 15152.3% (g/g) and gel fraction 56.6%. The increasing the concentration of cellulose caused the hardness value to be higher but the springiness value tends to decrease. Morphology analysis showed the surface of hydrogels that are porous, has lumps and forms a three-dimensional tissue.

Ganitri (Elaeocarpus sphaericus (Gaertn.) K. Schum.) adalah pohon cepat tumbuh yang banyak ditemukan di Sukabumi. Kayu ini tumbuh di hampir semua wilayah Indonesia. Tulisan ini menyajikan hasil pengujian sifat dasar (struktur anatomi, kimia, sifat fisis dan mekanis) kayu ganitri yang diambil dari hutan rakyat di daerah Sukabumi. Tujuan penelitian adalah untuk mengetahui potensi penggunan kayu ganitri berdasarkan sifat dasar dan penggunaan kayu oleh masyarakat sekitar. Hasil penelitian menunjukkan bahwa kayu ganitri memiliki kayu teras berwarna kuning dan kayu gubal berwarna putih. Corak kayu polos dan tekstur halus. Arah serat lurus sampai berpadu, kayu lunak, tidak mengkilap, dan tidak berbau. Berdasarkan nilai dimensi serat dan nilai turunannya, kayu ganitri termasuk ke dalam Kelas Mutu II. Kayu ganitri memiliki kadar holoselulosa dan selulosa yang tinggi (70,70% dan 54,58%), kadar sedang untuk lignin 21,60%, ekstraktif alkohol-benzena 3,47%, dan kadar abu 0,81%. Dengan berat jenis (BJ) kering udara 0,35 kayu ganitri termasuk ke dalam Kelas Kuat IV. Kayu tersebut disarankan untuk digunakan sebagai bahan bangunan konstruksi ringan, perkakas, furnitur, kayu lapis, papan sambung dan produk panel. Basic Properties of Ganitri Wood (Elaeocarpus sphaericus (Gaertn.) K. Schum from Sukabumi and Its Potential UsesAbsractGanitri (Elaeocarpus sphaericus (Gaertn.) K. Schum.) is a fastgrowing tree that is widely found in Sukabumi, West Java. It grows in all part of Indonesia. A research was carried out to investigate basic properties (anatomical, physical, mechanical, and chemical) of ganitri wood from the community forest of Sukabumi. The purpose of this study was to determine the potential use of ganitri wood based on its basic properties and local utilization. The results showed that the color of ganitri sapwood was white , and it was not clearly demarcated from the yellow, with fewer figure patterns. The texture was fine with straight to interlocked grain. The wood was soft, not lustrous, and no special odor. Based on the fibre dimensions and derivative values, the quality of ganitri wood fell in Class II as a raw material for pulp and paper. Ganitri had high holocellulose and cellulose levels (70.70% and 54.58%), moderate level in lignin (21.60%), and it contained 3.47% extractive soluble in alcohol-benzene, and 0.81% ash. Based on its air dry specific gravity (0,35), ganitri wood could be classified into wood Strength Class IV. The potential uses of ganitri are for lightweight construction material, tools, furniture, plywood, connecting boards, and other panel products.

Cassava tubers are one of the most starch producers in Indonesia, which is third after rice and corn. Cassava tubers starch can be used as raw material of natural polymer-based nanohydrogel synthesis. The use of natural polymers promises superior properties such as more eco-friendly, cheaper prices because their raw materials are available naturally in abundant quantities compared to synthetic polymers. To obtain similar properties to synthetic, this study modified starch using acid hydrolysis method for 2 hours and 24 hours. The ethanol precipitation method is then carried out to produce nano-particle starch. The process of nano-hydrogel formation was cunducted by gamma irradiation. The results showed that the size of starch nanoparticles was between 14.97 - 492.7 nm. Nano-hydrogel with gamma irradiation treatment has 256.81% of swelling power, 83.35% of gel fraction, and 3.81 mJ of hardness. Meanwhile, the treatment without gamma irradiation has 365.47% of swelling, but has an unstable structure, this is indicated by 61.45% of gel fraction and 2.36 mJ of hardness.