Emil Budianto

Synthesis of Amylopectin Macro-Initiator for Graft Copolymerization of Amylopectin-g-Poly(Methyl Methacrylate) by ATRP (Atom Transfer Radical Polymerization)

Graft copolymer of Amylopectin and PMMA was synthesized by atom transfer radical polymerization (ATRP) method. The hydroxyl groups of amylopectin partially substituted with tert-butyl a-bromoisobutyrate to form tert-butyl a-bromoisobutyrate (TBBiB ) groups. This compound is known as an efficient macro-initiator for ATRP process. This research, aimed to obtain a bio based polymer of Amylopectin, in which the amylopectin was used as macro-initiator in the ATRP of MMA. The experiment was carried out in the homogeneous system under temperature range of 40 – 70°C in DMSO solution using TEA as catalyst. The modified amylopectin-TBBiB then was grafted to methyl methacrylate trough ATRP. Product characterization indicates that the graft copolymer Amylopectin-g-PMMA is efficient and the obtained product owns well defined structures

Radiation Synthesis of Superabsorbent Poly(acrylamide-co-acrylic acid)-Sodium Alginate Hydrogels

Sodium alginate (NaAlg) is considered to be a potential natural polymer for biomaterial applications, because of its hydrophilic properties that is capable to increase the swelling of hydrogels and biodegradable. This study describes the synthesis of a poly (acrylamide-co-acrylic acid) NaAlg superabsorbent hydrogels via crosslinking gamma radiation. The effect of irradiation dose (20-40 kGy) and NaAlg concentration (0.1-0.7 %) of on swelling of hydrogels were studied. The copolymers were characterized by Fourier transform infra red spectroscopy (FTIR) and scanning electron microscopy (SEM) micrograph. The presence of the lowest (0.1%) NaAlg concentration provokes a significant increasing the equilibrium degree solution (EDS) of hydrogel up 800 g/g ,and the extent of gel fraction increases as a function irradiation dose up to about 99 %. The hydrogels were also found to be sensitive to the ionic strength of medium. The FTIR spectra of hydrogels were shown crosslinking occurs between acrylamide and acrylic acid and pores structures in the hydrogel observed by using SEM.

The Carbon Black Sonofication Effects on Vulcanisate Properties of Natural Rubber

The mechanical properties of natural rubber can be enhanced by the addition of carbon black. The mechanical properties change is highly affected by particle size and carbon black structure used. A modification of N660 carbon black was conducted in the research by sonoficating the carbon black for 3 and 5 hours (N600-M3; M5). The results of adding modified carbon black were characterised by Particle Size Analysis (PSA), Scanning Electron Microscopes - Energy Dispersive Spectrometry (SEM-EDS) and Thermogravimetric Analysis (TGA). The addition of modified carbon black shows bound rubber, thermal properties, and mechanical properties such as tensile strength, elongation at break and modulus 300% on the vulcanisate produced were increased from the vulcanisate that had been filled with N660 natural (N660-N). Keywords: natural rubber, carbon black, particle size, sonofication, characterisation

Effect of Sonofication of Carbon Black and 3-Aminopropyltriethoxysilane (APTS) on the Properties of Rubber-Carbon Black Composite

In order to improve the mechanical properties of natural rubber so it can be used as raw material for industrial component, it is required to add filler and coupling agent to the natural rubber. In previous study, carbon black obtained from sonofication process for 3 and 5 hours was added (filled) to improve thermal and mechanical properties of rubber-carbon black, where the improvement was influenced by the period of sonofication of carbon black, which subsequently added to the rubber-carbon black composite.In this study, various rubber-carbon composites have been synthesized using thin pale crepe (TPC) natural rubber as matrix, strengthened by carbon black N 660, sonoficated N 660, and addition of 2 phr of 3-aminopropyltriethoxysilane (APTS) to each composite. The obtained rubber-carbon black composite was characterized by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS). Universal Testing Machine was used to characterize its mechanical properties.Bound rubber value and mechanical properties of rubber-carbon black composite improved as a result of the addition of carbon black obtained from sonofication and APTS. However, contrast result was observed when sonoficated carbon black and APTS were added simultaneously.

Morphological Structure of Pretreated Organo Layer Silicate Dispersion in Masterbatch Biodegradable Polymer Cassava Starch Clay Nanocomposite

Biodegradable polymer using inexpensive renewable resources such as starch produced poor mechanical, barrier properties and transparency of product, these properties were the important parameter for packaging material. This research intended to study the effect of glycerol monostearate (GMS) treated organo layer silicate (OLS) in biodegradable polymer starch masterbatch to eliminate the inferior properties. Focus was in morphological structure of biodegradable polymer starch clay nanocomposite. Biodegradable polymer starch clay nanocomposite was prepared using Haake Rheomix Polydrive at a temperature of 100 °C for 5 minutes and screw speed 60 rpm and the product was used as masterbatch to get a better dispersion of OLS in the matrix. Masterbatch was formulated with the parameter of 35 %, 45 % and 50 % starch and 3.5 % of OLS. Morphological structure of biodegradable polymer starch clay nanocomposite was characterized using Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM) and X-Ray Diffraction (XRD) to observe the dispersion and compatibility of the organo layer silicate in biodegradable nanocomposite matrix. XRD analysis provided the dispersion of organo layer silicate at 35% starch was better than 45% starch and 50% starch in materbatch. This was consistent with the SEM and AFM result, masterbatch containing 50% starch had interfere the OLS dispersion and produced agglomeration of organo layer silicate. SEM images of masterbatch with 50 % loading level of starch shown structure that starch not completely thermoplasticized.