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Abstrak :
Telah dilakukan pembuatan (sintesa) polimer lateks dengan cara polimerisasi emulsi yang aplikasinya untuk meningkatkan California Bearing Ratio (CBR) tanah pada sub-grade jalan. Polimer lateks yang dihasilkan dikarakterisasi dengan Fourier Transform Infrared (FTIR). Kemudian dilakukan pengujian CBR pada tanah yang dipadatkan setelah dicampur dengan polimer tersebut. Pengukuran CBR dilakukan juga pada sampel yang direndam dalam air selama 4 hari. Diperoleh bahwa polimer lateks buatan ini memberikan hasil yang sangat memuaskan dibandingkan dengan polimer lateks lain (impor). Untuk polimer lateks yang didisain dengan Temperatur glass (Tg) (teori) sekitar 9.8º - 19.6º memberikan indikasi terbentuknya ikatan-ikatan C=O dan ?C-O-C- pada energi serapan 1732-1736 cm-1 sebagai gugus pengikat/binder. Hasil uji CBR memberikan nilai CBR sekitar 15-18 % terhadap tanah murni dengan pemadatan yang sama.

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Synthesize of emulsion polymer latex for sub-grade CBR improvement in the road construction. Latex polymer for California Bearing Ratio (CBR) enhancement in sub-grade soil of road building has been prepared by emulsion polymerizations technique. The prepared polymer then characterize by Fourier Transform Infrared (FTIR). For application purpose, CBR test was done to the compacted polymer added-soil. The CBR test is done also for both soaked and unsoaked samples. It is found that our latex polymer is better then other imported latex polymer. For the latex polymer, which is design to have Temperatur glass (Tg) around 9.8-19.6o, indicating the formation of C=O and ? C-O-C- bonds at 1732-1736 cm-1 energy absorption as binder groups. CBR test results show that our latex polymer has CBR value around 15-18 % compare to the soil without polymer binder.

Abstrak :
A phase field model has been successfully constructed to simulate the behavior of the semi-crystalline polymer solidification phenomenon. It is a model that has been widely and successfully utilized to simulate solidification phenomena in metals. However, the non-conserved phase field equation can be extended to include unique polymer parameters that do not exist in metals; for example, polymer melt viscosity and the diffusion coefficient. In order to extend this model, we incorporate free energy density and non-local free energy density based on the Harrowell-Oxtoby and Ginzburg-Landau theorems for polymer. By using the expansion principle for the higher order of binary phase field parameter, a full modified phase field equation can be obtained. The solidification phenomenon in polymer is very important to optimize the final properties of the products. Here, we use our modified equation to investigate the effect of melting temperature on the rate of solidification. It was found that the rate of solidification is correlated with melting temperature in a non-straightforward manner.

Abstrak :
Dalam penelitian ini dilakukan sintesis polistirena-ko-poli(etil akrilat) dengan metode Atomic Transfer Radical Polymerization (ATRP) untuk mempelajari pengaruh konsentrasi stabilisator dan inisiator terhadap solid content dan viskositas, serta mempelajari pengaruh variasi komposisi monomer terhadap temperatur transisi gelas (Tg). Dari hasil penelitian didapatkan bahwa semakin tinggi konsentrasi stabilisator dan inisiator maka solid content dan viskositas akan semakin tinggi, dan pada variasi komposisi monomer tidak memberikan kecenderungan pada temperatur transisi gelas yang dihasilkan. Terbentuknya polistirena-ko-poli(etil akrilat) ditunjukkan oleh hasil karakterisasi dengan Fourier Transform Infra Red dan Differential Scanning Calorimetry yang terlampir dalam penelitian ini dan memiliki hasil tidak terbentuk homopolimer dari masing-masing monomer.

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In this research, the synthesis of polystyrene-co-poly(ethyl acrylate) by the method of Atomic Transfer Radical Polymerization (ATRP) has been done to study the effect of the concentration of stabilizers and initiators on the solid content and viscosity of them. Then, this experiment also studied the effect of variations of monomers composition on the glass transition temperature (Tg) of polystyrene-co-poly(ethyl acrylate). The result showed that the higher concentration of stabilizers and initiators were, the higher the solid content and viscosity of the copolymer was obtained. In addition, the monomers composition did not affect the glass transition temperature of the resulting copolymers. The formation of polystyrene-co-poly(ethyl acrylate) was characterized by Fourier Transform Infra Red and Differential Scanning Calorimetry and the results showed that the formation of two homopolymers did not appeared.