No abstract

Natural rubber is widely known to possess good mechanical properties. However, due to the existence of numerous reactive double bonds on the molecular backbone, natural rubber is highly susceptible to degradation by thermal aging. To overcome such shortcomings, natural rubber is frequently blended with synthetic rubbers such as chloroprene rubber. Chloroprene rubber is one of the most important specialty rubber for nontire application, for example rubber fender. The present study investigates the effects of two different blend ratios of natural rubber (standard Indonesian rubber or SIR 10) and chloroprene rubber on the cure, tensile properties, and morphology of rubber blends. The blends of SIR 10/chloroprene rubber are prepared by using laboratory kneader and laboratory two‐roll mill. Rubber blending is made from mixture of natural rubber SIR 10 and synthetic rubber chloroprene rubber with variation of SIR 10/chloroprene rubber ratio PF1 100/0; PF2 70/30; PF3 30/70; PF4 0/100 phr. Furthermore, each variable is tested to determine the rheological and mechanical properties including tensile strength, elongation at break, hardness, and compression set. The addition of chloroprene rubber also causes an increment in the tensile strength and elongation at break. However, only PF3 shows satisfied result compared to the requirements standard (ISO 17357‐1:2014 Ship and Marine Technology‐Floating Pneumatic Rubber Fenders).

Pipa apung banyak digunakan pada industri pengerukan dan industri perminyakan.  Dari penggunaannya maka spesifikasi pipa apung harus mempunyai daya lentur (elasticity), kekuatan (strength), tahan air (water proof), tahan minyak (oil resistance), dan tahan panas (hot resistance).  Untuk itu pada pembuatannya, pipa apung membutuhkan bahan baku yang baik diantaranya adalah bahan tekstil (kanvas) sebagai penguat yang terdiri dari serat-serat tekstil.  Dari hasil penelitian serat nylon mempunyai keunggulan sebagai penguat tekstil baik itu digunakan dalam bentuk benang maupun bentuk kain untuk pembuatan pipa apung. Pada pembuatan hose, bagaimanapun ikatan antara nylon dan karet sangat dibutuhkan untuk menerima beban yang besar, untuk itu dibutuhkan suatu adhesif yang dapat menyatukan antara nylon dan karet.  Dari pengujian yang dilakukan dapat disimpulkan bahwa pipa apung buatan BPPT telah memenuhi standard penggunaan pada industri perminyakan.

Chitosan is a natural polymer gotten from shrimp and crab skeleton; chemical structure of chitosan is similar to cellulose where hydroxyl (OH) in glucose molecule in cellulose is replaced by amine (-NH 2) in chitosan. From the chemical structure and its properties, chitosan can be used as a filler and adhesive to replace the traditional materials and it will improve several properties of papers such as to increase strength, reduce water absorption, increase smoothness, and probably anti bacteria and anti fungus of the papers. The use of chitosan in paper production can also reduce impact on environment, because chitosan is a natural polymer that is degradable. In this research, chitosan will be applied into paper processing to replace filler and also as an adhesive to increase the properties of the paper. The result shows that low molecular weight chitosan, 1%, can affect the decrease of water absorption property and increase paper strength and the smoothness of the paper.

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