THE EFFECT OF VEGETABLE PLASTICIZER ON THE PROPERTIES OF NATURAL RUBBER/POLYPROPYLENE BASED THERMOPLASTIC ELASTOMER

Dwi Wahini Nurhajati*, Supraptiningsih, Nursamsi Sarengat

ABSTRACT
Vegetable plasticizer is a plasticizer that is derived from renewable raw materials, used as an alternative to petroleum-based plasticizer. The purpose of this research was to compare the effect of the vegetable and petroleum plasticizers on the mechanical properties of thermoplastic elastomer (TPE). Vegetable plasticizer used in this study was a modified castor oil. Natural rubber/polypropylene (KA/PP) based TPE was made in an internal mixer at a temperature of 180ºC with various KA/PP ratio and type of plasticizer. In general, modified castor oil as a plasticizer has a more positive effect on the mechanical properties of TPE in various ratios of KA/PP, mainly related to improvement of properties of tensile strength, elongation at break and flexing resistance 100 kcs. The best formula of TPE is a TPE that is composed of KA/PP 60/40 using modified castor oil. XRD results showed that TPE is dominated by amorphous phase.
Keywords: castor oil, natural rubber, polypropylene, TPE

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THE GROWTH OF EARTHWORM Eisenia fetida sp. ON THE FLESHING WASTE COMPOST

Prayitno

ABSTRACT
The use of earthworm as a source of income and a means for managing organic solid waste such as fleshing waste has been widely applied. The aim of this research was to find the optimum ratio between fleshing waste and cow dung in the growing medium of Eisenia fetida sp. This research was conducted by growing the E. fetida sp. earthworm in the medium containing fleshing waste mixed with cow dung. The ratio of fleshing waste and cow dung was varied at 0:100; 10:90; 20:80; 30:70; 40:60; and 50:50. In addition, 2 parts of chopped stubbles per part of every sample was added as a carbon source. The prepared media were fermented for three weeks with EM4 as a starter, followed by incubation of the earthworm for six weeks. The weight and the number of earthworm were evaluated every two weeks. The optimum growth of earthworm was achieved at the 2nd week of incubation with 185.48% and 121.10% increase of weight and number of earthworm, respectively, at 40:60 ratio of fleshing waste and cow dung in the growing medium.
Keywords: earthworm, fleshing waste, incubation.

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THE EFFECT OF PRESERVATION METHODS ON SHRINKAGE TEMPERATURE OF PUFFER FISH SKIN USING DIFFERENTIAL SCANNING CALORIMETER (DSC) ANALYSIS

RLM. Satrio Ari Wibowo*, Muh. Wahyu Sya’bani

ABSTRACT
The aim of this study was to determine the effect of the skin preservation type against shrinkage temperature of leather. The material used in this study was the skin of pufferfish (Arothon reticularis) that have been preserved by salting, formaldehyde and pickling and also raw skin as a reference. The method used to measure the shrinkage temperature was thermal analysis using differential scanning calorimeter (DSC) that operated from 4°C up to 440°C with nitrogen stream. DSC measurement results showed that shrinkage temperature of puffer fish preserved with formaldehyde was higher than salting and pickling, which is 63.64°C; 47.95°C; 57.37oC respectively. The advantage of using formaldehyde compared to others preservation technique was not only can protect the skin from damage by microorganisms, but also can create a bond with the collagen.
Keyword: Puffer fish, differential scanning calorimeter, skin preservation.

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THE EFFECT OF CONVENTIONAL (CV) AND SEMI EFFICIENT (SEV) CURING SYSTEM ON AGING AND THERMAL PROPERTIES OF NATURAL RUBBER AND BUTYL RUBBER BLENDS VULCANIZATES

Arum Yuniari*, Muhammad Sholeh, Ihda Novia Indrajati

ABSTRACT
The purpose of this research was to study the effect of CV and SEV curing systems on aging and thermal properties of natural rubber and butyl rubber blends. The mixing of rubber and rubber chemicals using two roll-mills and the vulcanization process was carried out by the hydraulic press at 160°C and 150 kg/cm2. The research design used two variations; first, the CV curing system (accelerator/sulfur) (1.0/2.5) phr and SEV curing system (accelerator/sulfur) (2.1/1.5) phr, second, the ratio of natural rubber/butyl: 100/0; 95/5; 90/10; 85/15; 80/20; 75/25; 70/30; 65/35; 60/40 and 55/45 phr. The parameter observed were tensile strength, elongation at break, hardness before and after aging and thermal properties, e.g. TG/DTA and DSC. The results showed that CV curing systems provided tensile, elongation at break properties gave higher quality and better aging properties. TG/DTA analysis of vulcanizates processed with CV curing systems provided slightly better thermal stability than of the SEV curing system.

Keywords: natural rubber, butyl rubber, curing, CV, SEV, aging, thermal.

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PHYSICAL, CHEMICAL, AND MORPHOLOGICAL PROPERTIES OF TANNED GOAT JACKET LEATHER USING RECOVERED CHROME FROM TANNING WASTE WATER

Sri Sutyasmi

ABSTRACT
The purpose of this study was to recover chrome in tanning waste water to reduce environmental pollution and to utilize chrome as tanning agent. Chrome in tanning waste water leaching out of the drum was filtered and put in the tank and subsequently it was added with NaOH to generate chrome hydroxide. Furthermore, chrome hydroxide was converted to chrome sulfate as tanning agent by addition of concentred sulfuric acid. Cr2O3 content of chrome sulfate was determined before being used for tanning. The result showed that Cr2O3 content was 3958.6 mg/l. Variation of recovered chrome sulfate concentrations for tanning jacket leather were 25, 50, 75 and 100% respectively. Controls were made with the use of 100% of industrial grade chrome sulfate. The best result were goat jacket leather tanned with recovered chrome of 75 and 100 % for its physical properties and 25% for its chemical properties. Test results of SEM showed that chrome was morphologically presence in tanned goat leather mass.

Keywords: tanning, jackets leather, chrome recovery, physical and chemical properties, leather morphology.

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INFLUENCE OF VARIOUS TANNING AND FINISH TYPE ON MORPHOLOGY, ORGANOLEPTIC AND MECHANICAL PROPERTIES OF MONITOR LIZARD SKIN (Varanus salvator)

Emiliana Kasmudjiastuti*, Sri Sutyasmi, Rihastiwi Setiya Murti

ABSTRACT
Monitor lizard (Varanus salvator) skin is exotic leather because it has a unique grain. Therefore, the original grain of the animal needs to be maintained in the finishing process so that its performances look likes natural. This research aimed to study the effect of tanning materials (vegetable and chrome) and the type of finish (natural, aniline, semi-aniline and two tone) on morphology, organoleptic and mechanical properties of lizard skin. The materials used in this study were dry preserved lizard skins. The research varied on the types of tanning (vegetable and chrome) and the type of finish (natural, aniline, semi-aniline and two tone) each by varying the finishing materials (casein and protein binders). The tests were conducted on the observation of the structure using photomicrographs, rub fastness, adhesion of finish strength, tensile strength, elongation at break and organoleptic. The results showed that the best result was vegetable tanned lizard skin using natural finish with casein and met the requirements of SNI 06-4362-1996, lizard skin for shoe upper. This gave dry and wet rub fastness of 5 and 5 respectively; dry and wet adhesion of finish strength of 650 and 100 g/cm respectively; tensile strength of 207.43 kg/cm2; elongation at break of 37.52% and organoleptic value of panelists observations of 87.9 (good).

Keywords: Monitor lizard (Varanus salvator) skin, tanning, finish type, morphology, organoleptic and mechanical properties.

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EFFECT OF VULCANIZATION TEMPERATURE ON THE MECHANICAL PROPERTIES OF VULCANIZED NATURAL AND ACRYLONITRILE-BUTADIENE RUBBERS

Norma Arisati Kinasih*, Mohamad Irfan Fathurrohman, Dadang Suparto

Abstract

Natural and acrylonitrile-butadiene rubbers possess different vulcanization characteristics. Selection of the vulcanization system and temperature affects the mechanical properties of vulcanized natural rubber (NR) and acrylonitrile-butadiene rubber (NBR). In the present work, the effect of vulcanization temperature (150, 160, 170 and 180oC) on the mechanical properties of NR and NBR vulcanizates was studied. The effect of different vulcanization system (semi efficient, efficient and sulfur donor) was studied in NR blends, while the effect of different acrylonitrile content (26, 28 and 33 wt %) was studied in NBR blends. The NBR curing characteristics and mechanical properties data showed that vulcanization at low temperature (150oC) was suitable for low acrylonitrile-NBR, whereas that at high temperature (170oC) was suitable for high acrylonitrile-NBR. In addition, the semi efficient system at low temperature vulcanization (150oC) was suitable for natural rubber.

Keywords: vulcanization temperature, acrylonitrile, NBR, natural rubber, mechanical properties.

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Penelitian sifat sifat fisika sol plastik

Susilowati Susilowati

The physical properties of plastic soles especially flexible soles and spons soles for footwear (shoes, sandals, etc) are very important. This physical properties are : tensile strength; elongation at break; tensile stress at 100%; hardness; density; tear resistance; permanen set; abrasion resistance and flexing. The type of plastic material used for flexible and spons plastic soles, as recorded by infrared spectrophotometry analysis indicate that most of them are made by PVC. Physical test result shown that plastics soles can be graded into three categories in comparation with the specification of the IIS (Indonesian Industial Standard) number SII 1103 – 84.

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