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"Penilitian ini berfokus pada sintesis Polivinil Asetat (PVAc) emulsi dengan penambahan polivinil alkohol (PVA) sebagai agen pelindung koloid. Sintesis dilakukan dengan penambahan PVA menggunakan tiga jenis PVA terhidrolisis Sebagian yang dibedakan berdasarkan derajat polimerisasinya yaitu rendah, sedang, dan tinggi. Selama reaksi berlangsung sistem berada pada temperatur 70-800C, kecepatan agitator 300 rpm, dan menggunakan teknik semi-continuous selama 5 jam. Beberapa karakterisasi PVAc yang terukur sebagai parameter antara lain temperatur antara 67-770C, pH antara 6-1, densitas antara 1,19-1,2 g/mL, kandungan padatan yang memiliki rentang nilai 19,75-22,29 %, ukuran partikel antara 67,1-1310,5 nm, berat molekul 1307,4015-5226,3346 g/mol, viskositas antara 1,01-11,07 mPa.s. Efek penambahan PVA sebagai agen pelindung koloid akan memengaruhi nilai viskositas dari hasil akhir polimerisasi. Selain itu juga dapat memengaruhi kekuatan daya rekat pada sintesis polimerisasi.

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This research focuses on the synthesis of polyvinyl acetate (PVAc) emulsion with the addition of polyvinyl alcohol (PVA) as a protective colloid agent. The synthesis was carried out by adding PVA using three types of partially hydrolyzed PVA which were distinguished by their degree of polymerization, i.e. low, medium, and high. During the reaction, the system was at a temperature of 70-800C, stirring 300 rpm, and used a semi-continuous technique for 5 hours. Characterizations of PVAc that are measured as parameters include temperature at 67-77⁰C, pH at 6-1, density at 1.19-1.2 g/mL, solids content which has a value range from 19.75-22.29%, particles size at 67.1-1310.5 nm, molecular weight at 1307.4015-5226.3346 g/mol, viscosity at 1.01-11.07 mPa.s. The effect of adding PVA as a protective colloid agent will affect the viscosity value of the final polymerization result. In addition, it can also affect the adhesive strength of the polymerization synthesis."

"Limbah pertanian di negara agraris seperti Indonesia sangatlah potensial. Pengolahan limbah pertanian seperti jerami padi akan memberikan nilai tambah ekonomis bagi para petani di Indonesia. Salah satu caranya adalah dengan pembuatan biokomposit perupa papan serat jerami dan serat gelas dengan polimer PVAc. Papan serat ini berpotensi menjadi material struktur yang murah dan mudah di dapat dikarenakan jumlahnya yang melimpah dan murah. Untuk meningkatkan kekuatan jerami dalam pembuatan papan serat dilakukan proses awal berupa perendaman jerami dalam cairan NaOH. Hal ini dilakukan untuk memperbaiki sifat mekanis jerami. Untuk mendapatkan komposisi yang terbaik maka dibuat beberapa komposisi serat papan jerami mulai dari 20% berat serat hingga 70% berat serat. Komposisi optimal papan serat jerami padi berada pada 30% berat serat dengan kekuatan tarik sebesar 4.5 MPa. Variasi subtitusi serat gelas pada komposisi optimal papan jerami padi menghasilkan kekuatan optimal pada komposisi 50% jerami padi, 50% serat gelas dan 70% PVAc yaitu sebesar 4.26 MPa. Rata- rata kadar air 10% atau dibawah 13% menunjukkan papan serat ini sesuai dengan SNI 01-4449-2006.

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Agricultural waste in an agricultural country like Indonesia is very potential . Processing of agricultural wastes such as rice straw provides economic value for farmers in Indonesia. One way of agricultural processing is to manufacture biocomposites such as rice straw fiber and glass fiber hybrid boards with PVAc polymer. This fiberboard material could potentially as structural materials and can an inexpensive because the fiber source is abundant and cheap. To increase the strength of the fiberboard made an initial process of soaking hay in an NaOH solution was conducted.

From this research it was found that the optimal composition of the rice straw board was at 30 % by weight of rice straw with a tensile strength of 4.5 Mpa, increased BLA % compared to tensile strength of the pristine PVAc. Moreover, the optimal composition of the hybrid board was 50 % rice straw, 50 % glass fiber and 70 % PVAC and this composition resulted a tensile strength of 4:26 MPa . The tensile strength of the hybrid board was smaller than that of the straw board becuase of the presence of big voids in between the straw and the glass fibers. Average moisture content of 10 % met the SNI 01-4449-2006 criteria , which was below 13 %."

"ABSTRAKLatar Belakang: Pada penelitian tahun 2005-2010 ditemukan pekerja PT. X yang terpajan VCM berisiko 2.15 kali menderita gangguan enzim hati. Sehingga perusahaan melakukan program pencegahan dan pengendalian faktor resiko. Pada penelitian ini ingin melihat pengaruh pajanan VCM serta faktor lainnya terhadap perubahan kadar enzim hati pekerja PT. X ini setelah dilakukan upaya perbaikan.Metode: Desain penelitian adalah Kohort Retrospektif menggunakan data sekunder MCU tahun 2011-2015. Melibatkan 196 orang sampel, dimana pekerja terpajan VCM 98 orang dan sisanya tidak terpajan VCM. Saat awal, kondisi enzim hati seluruh sampel dalam batas normal. Penilaian peningkatan enzim hati berdasarkan enzim AST dan ALT. Analisis statistik menggunakan Chi Square dengan p< 0.05. Multivariat menggunakan Regresi Cox.Hasil: Didapatkan 76 orang (38.8%) mengalami peningkatan enzim hati, 40 orang (40.8%) pekerja terpajan VCM dan 36 orang (36.7%) tidak terpajan VCM. Jumlah kasus baru tahun 2012 adalah 14.3% menurun menjadi 4.6% tahun 2015. Hasil analisis Chi Square menyatakan tidak ada hubungan bermakna antara faktor usia, jenis kelamin, masa kerja, posisi jabatan, indeks masa tubuh, obesitas sentral, riwayat DM dan kebiasaan olah raga dengan perubahan kadar enzim hati (p > 0.05). Untuk Regresi Cox menegaskan bahwa tidak ada hubungan bermakna antara pajanan VCM (RRsuaian=0.82; IK95% = 0.52-1.31; p=0.410) terhadap perubahan kadar enzim hati. Kesimpulan: Pajanan VCM tidak berpengaruh terhadap perubahan kadar enzim hati. Perubahan kadar enzim hati yang terjadi berupa penurunan karena jumlah kasus baru terus menurun setiap tahun.

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ABSTRACTBackground: In the 2005-2010 study found that PT. X workers exposed to VCM had a 2.15 times greater risk of liver enzyme disorders. So the company conducted prevention and control programs against the risk factors. In this study we want to see the effect of VCM exposure and other factors on alteration in liver enzyme levels of PT. X workers after the improvement effort.Method: The study design is Retrospective Cohort using secondary data of MCU in 2011-2015. There are 196 persons involved as samples, where 98 workers are exposed to VCM and the rest are not exposed to VCM. At baseline, the liver enzyme conditions throughout the sample are within normal limits. Assessment of elevated liver enzymes based on AST and ALT enzymes. The Chi-squared test with p <0.05 is used for statistical analysis. Multivariate uses Cox Regression.Results: 76 people (38.8%) had elevated liver enzymes, 40 (40.8%) exposed workers VCM and 36 people (36.7%) were not exposed to VCM. The number of new cases in 2012 is 14.3% decreased to 4.6% in 2015. Chi Square analysis results show no significant relationship between age, sex, work period, job title, body mass index, central obesity, history of DM and exercise habits with liver enzyme levels alteration (p> 0.05). The Cox Regression test confirms that there is no significant association between VCM exposure (RRadjusted=0.82; CI95%=0.52-1.31; p=0.410) to liver enzyme levels alteration.Conclusions: VCM exposure has no effect on alteration in liver enzyme levels. Alteration of liver enzyme that occur is a decrease as number of new cases continues to decline every year."