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Cyclic natural rubber have low compatibilities when mixed with other polymer. The compatibility of a cyclic natural rubber (CNR) could be increased through grafted functional monomer to the polymer backbone. This research aims to know about influence of maleic anhydrate concentration (3-15 phr) as monomer, concentration of benzoyl peroxide (0.05-0.2 molar ratio) as initiator and times (15-90 minute) towards grafting degree of maleic anhydride. The research conducted with reflux in oil bath, at constant temperature 110ºC. The grafting degree determined with titration method and FTIR analysis used to show the existence of grafted maleic anhydrate onto cyclic natural rubber. Result of FTIR analysis showed that grafted anhydrate to cyclic natural rubber assigned with the presence of carbonyl absorptions (C=O stretching). Result titration showed that concentration of maleic anhydrate and benzoyl peroxide enhanced as well as grafting degree. While for variation of time, optimum grafting degree achieved at 60 minute.

Abstract. The research has done analysis of thermal properties and solubility test of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR). Cyclic Liquid Natural Rubber (CLNR) is a cyclical natural rubber which has decreased molecular weight. Synthesis of Cyclic Liquid Natural Rubber (CLNR) do by oxidative degradation after cyclic.  Oxidative degradation after cyclic using Cyclic Natural Rubber (CNR) and phenylhydrazine reagent with flow rate 2 LMin-1 of oxygen atmosphere during 24 hours. Thermal analysis of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) by Differential Scanning Calorimetry (DSC),the glass transition temperature (Tg) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 102,82  o C and 103,67 o C, the crystal transition temperature (Tc) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 362,45 o C and 330,29 o C and the melting transition temperature ( Tm) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 509,24 o C and 440,00 o C. Solubility test by dilute Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) in some solvent with different properties and polarity index. Solubility test shows the results Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR)  has polarity index around 2,4 – 4,4 and 2,4 and 4,4.               Keywords: CLNR, CNR, oxidative degradation

This study purpose to determine the improvement of chemical learning outcomes and student learning activities that used e-learning media with problem based learning models on the subject of salt hydrolysis. The design was used One Group Pretest and Postest. The instrument used two domains, namely cognitive and affective. Hypothesis testing is carried out using the two-part of t-test. The hypothesis's test of student learning outcomes obtained t count = 29.5 while t table = 2.03 for α = 0.05 and db = 34. Thus t count > t table then the hypothesis of Ha is accepted. It concluded that there is an improvement in students' chemistry learning outcomes on salt hydrolysis subject that used e-learning media with problem based learning models. Not only the percentage increased in learning outcomes of 68.4%, but also the percentage of student learning activities of 84% which means very active.

Modification of natural rubber by Grafting method using monomer maleate anhydride is a technique of  modification of natural rubber polymers that aims to change the physical and chemical sifak of natural rubber  polymers. The grafting process is carried out by comparing the amount of MA that is graphed based on the type of peroxide, the variation of peroxide concentration and the variation of MA concentration. FTIR test results showed the appearance of peak absorption at the wave number of 1710-cm cluster C=O carbonyl from MA that is graphed in natural rubber.. Based on the comparison of ir analysis of peroxide concentration used i.e. (0.01, 0.05 and 0.1) molar ratio obtained the largest carbonyl index at DCP concentration of 0.05 mr similarly, the  comparison of IR analysis results of MA concentration variations (3, 6, 9, 12) phr shows the largest carbonyl  index that appears in the C=O absorption area is in the KA-g-MA sample with a MA variation of 12 phr with  Carbonyl index = 45.81. The degree of MA grafting on natural rubber structures increases with increased MA concentration.