Judul: Rekayasa proses produksi bioplastik berbahan baku pati termoplastik dan polietilen
Abstrak: Plastics have been used widely for packaging materials. However, plastic wastes can pollute environment because of its persistency to be biodegraded by microorganisms. Efforts have been conducted to develop environmental friendly plastic from renewable resources. Problems encountered in the manufacture of bioplastic are poor physical-mechanical properties and incompatibility between hydrophilic/polar and hydrophobic/non-polar materials. The modification of raw materials and use of compatibilizer can be applied to improve the compatibility between the two material blends. The purpose of this study is to develop a process of manufacturing bioplastic by modifying the raw material characteristics and the use of compatibilizer. This study consisted of three steps, namely preparation of thermoplastic starch, preparation of maleic anhydride (MA) grafted with LLDPE/HDPE (LLDPE-g-MA/HDPE-g-MA) and manufacturing process of bioplastic. Thermoplastic was prepared by mixing distilled water and glycerol with tapioca, and then allowed to aging for 8 days to a mixture of distilled water and glycerol can be absorbed completely into raw materials (tapioca). Grafting of maleic anhydride with LLDPE/HDPE (LLDPE-g-MA and HDPE-g-MA) was carried out in a twin screw extruder. There were three levels of maleic anhidride concentration namely 2.5%, 5%, 7.5% (w/w) and dicumyl peroxide 0.1% (w/w polymer) used in this experiment. After mixing LLDPE-g-MA and HDPE-g-MA compatibilizer with thermoplastic starch (TPS), the resulting mixtures were then extrudered with LLDPE/HDPE. Four ratios between LLDPE/HDPE and TPS were investigated namely 0:100; 20:80; 40:60; and 60:40. The plastic properties observed included melt flow rate, density, thermal, mechanical, barrier, and degradation properties. The results showed that increasing thermoplastic starch content decreased melt flow rate, melting temperature, mechanical, oxygen transmition rate properties and increased density, water vapor transmition rate and its biodegradability. The presence of LLDPE-g-MA/HDPE-g-MA compatibilizer resulted in better physical and mechanical properties of bioplastic. The compatibilizer improved surface adhesion and decreased surface tension between TPS and LLDPE/HDPE matrix. The best formulation for wrapping applications was the LLDPE-TPS with 40% of TPS and 5% MA with 6,96% of grafting degree, whereas that for plastic bag applications was HDPE-TPS with 30% of TPS and 7,5% MA with 3,21% of grafting degree. Stability tests of bioplastic TPS-LLDPE and TPS-HDPE for packaging applications at room and low temperature showed no significant changes in the mechanical properties, permeability, and morphology, and therefore the product has the ability to maintain mechanical properties at low temperature.
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Judul: Produksi Plastik Komposit dari Pencampuran Tapioka dan Onggok Termoplastis dengan HDPE.
Abstrak: Plastic is one of synthetic polymer which globally applicated because of its advantages. However, many problems emerged when plastic was discarded which cause serious environmental pollution because it can not be degraded, while its utilization increases year to year. Development of starch-based biodegradable plastic can be one alternative to solve this problem and expected to increase the added value of local agricultural products. This research aims are to study the production of composite biodegradable plastic using blending method of natural (tapioca and cassava bagasse) and synthetic (HDPE) polymers; and to analyze mechanical, thermal, and biodegradability characteristics of the composite plastic. The research was preceed with preparation and characterization of tapioca and cassava bagasse as composite plastic materials. It was followed with preparation of thermoplastic starch by adding plasticizers. Water is added up to 25% concentration of material total mass, while glycerol is added in 15% and 20% concentration. Compatibilized HDPE was made by adding 0,1% of dicumyl peroxyde and 1% of maleic anhydride in HDPE resin. The last step is processing composite plastic using blending method of thermoplastics starch and compt.HDPE in 20% and 80% ratio. Composite plastic then evaluated for its mechanical, thermal, and biodegradability characteristics. Based on quality requirement, tapioca has good quality appropriate with SNI 01-3451-1994. Result of characterization showed that cassava bagasse has high fiber content up to 33,80%. Based on the results of mechanical properties testing, it is known that compt.HDPE-tapioca with the addition of 15% glycerol has a tensile strength close to HDPE resins, as well as the elongations value. Thermal properties testing showed that the addition of 20% natural polymers in blending process gave insignificant influence. The results of biodegradability examination showed that composite plastics are capable to be degraded by microorganism. In qualitative examination, it can be seen from the growth of the fungi in some parts of the sample surface. In quantitative examination using enzymes, percentation of compt.HDPE-cassava bagasse weight loss was larger than compt.HDPE-tapioca. This is influenced by the use of α-amylase and cellulase in compt.HDPE-cassava bagasse so that the total glucose results higher, which means more degradable.
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Judul: Infeksi Cacing Jantung Dirofilaria Immitis, Railliet & Henry, 1911 Pada Anjing
Abstrak: Cacing Dirofilaria immitis dewasa yang tinggal dalm ventrikel kanan jantung anjing, sering kali menimbulkan gejala klinis yang cukup berat. Cacing Tersebut menghasilkan mikrofilaria yang selanjutnya berkembang menjadi larva infektif dalam saluran malphigi induk semang entara, yaitu nyamuk dari genus Culex, Aedes dan Anopheles.
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