PENGARUH PERBEDAAN METODE MELT PROCESSING DAN SISTEM LARUT TERHADAP HASIL GRAFT KOPOLIMERISASI CYCLIC NATURAL RUBBER (CNR) DENGAN GLYCIDYL METHACRYLATE (GMA)

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

The process of thermally grafting glycidyl methacrylate (GMA) on cyclic natural rubber (CNR) compared to the addition of an initiator of organic peroxide, dicumyl peroxide (DCP) and using cross-linker divinyl benzene (DVB) has been carried out by means of melt processing. The main aims of the modified GMA grafted to CNR was to increase the polarity of the polymer to be used as a compatibiliser agent in asphalt modification. The addition of DVB comonomer in the processing was to increase the amount of GMA implanted in cyclic rubber as measured by the degree of GMA grafting. The grafting method was carried out by melting polymer (melt processing) at high temperatures in the reactor internal mixer (Brabender model). The grafting reaction took place at a temperature of 160°C, 60 rpm rotor rotation for 10 minutes of mixing. To determine the GMA grafting reaction on cyclic rubber, characterization was carried out with Fourier Transformed Infra Red (FT-IR) while the degree of GMA grafting on natural rubber was determined by acid-base titration method in organic solvents. It was found that the GMA grafting process on cyclic natural rubber could easily occur in the melting phase at high temperatures and increase with the addition of dicumyl peroxide (DCP) peroxide. Although the addition of divinyl benzene (DVB) comonomer can increase the degree of grafting of GMA on CNR, the addition of comonomer can cause high cross-linking.

The primary focus of this study was to determine the grafting of oleic acid (OA) onto cyclic natural rubber (CNR) using dicumyl peroxide (DCP) as an initiator. The grafting was carried out in a Haake rheometer internal mixer. Influence of OA monomer and DCP initiator concentrations were studied. Determination of the degree of grafting is done by the acid-base titration method. Base on FT-IR data spectra, the peaks at 1712.8 cm-1 show the carbonyl group (C=O), which proves the grafting of OA onto CNR was successfully achieved. The quantities of the grafted OA on CNR molecules was increased with increasing monomer and initiator concentrations. The glass transition (Tg) temperature also increased with increasing the monomer concentration used in the graft copolymerization. The glass transition values CNR increase from 100.4 °C to 115.86 °C, which proves, grafted OA onto CNR was successfully obtained.

Research on the modification of Cyclic Natural Rubber (CNR) grafting Oleic Acid (OA) copolymer using initiator of Benzoyl Peroxide (BPO) and the filler of bentonite-Cetil Trimethyl Ammonium Bromide (CTAB) has been carried out, which aims to determine the method of modifying Cyclic Natural Rubber (CNR) and Oleic Acid (OA) so it can produce CNR-g-OA copolymer through grafting method with BPO initiator mixed together with bentonite-CTAB. This research was conducted in three stages. The first stage is the process of dissolving CNR using xylene. The second stage is the process of mixing CNR solution and OA with the composition (70:30) phr, followed by the addition of BPO initiator and bentonite-CTAB filler. The third stage is characterization using FTIR and Scanning Electron Microscopy (SEM). The results of the analysis using FT-IR showed an absorption at 1708,23 cm-1 which indicated the presence of C=O bonds from oleic acid which had been grafted on CNR, and increased intensity after addition of bentonite-CTAB at 1568,96 cm-1; 1446,13 cm-1; 1255,66 cm-1; and 866,94 cm-1. Characterization results using SEM showed that the mixing of Bentonite-CTAB in KAS-g-OA was evenly distributed and quite homogeneous.

Effect of Graft copolymerization of oleic acid on to cyclic natural rubber in polyamide

The research on the degree of grafting of maleic anhydride (MA) on Cyclic Natural Rubber/CNR with the initiator Dicumyl Peroxide (DCP) has done . Grafting process carried out by reflux in a flask technique coupled with the base of the condenser and oil bath at a temperature of (105-110)°C, variations in the concentration of MA (3, 6, 9, 12, 15) phr, DCP variation inisi a tor concentration (0.05; 0.1; 0.15) molar ratio and variation in time (15, 30, 60, 90) minutes. Determination of the degree of grafting is then performed by the method of titration and FTIR spectra analysis to determine the grafting of MA on CNR chain. The results showed that the MA-g-CNR occurs at 15 phr comparison with the degree of grafting of 0.12% for the variation of the concentration of MA; 0.15 molar ratio to the degree of grafting of 0.07% for the variation in concentration of DCP inisiatior; 90 minutes with a degree grafting of 0.14% for the time variation. Keywords: grafting, cyclic natural rubber, maleic anhydride, dicumyl peroxide

The r esearch of grafting methyl methacrylate (MMA) on to Cyclic Natural Rubber (CNR) has been carried out. Benzoyl Peroxide (BPO) was used as a inisiator and temperature condition at 90 o C with variation of time 1 and 2 hour s . Grafting p rocess was done with technique of reflux in a tree-neck flask with condenser and oil bath. Spectra analysis FTIR performed for determine the presence of graft ed MMA on the backbone of CNR. The results showed that the product CNR-g-MMA was formed with the marked appearance of the absorption peak wave numbers at 1731 and 1730 cm-1 (carbonyl group absorption) typical for carbonyl (C = O) of metal methacrylate. The degree of grafting increased with the increasing time grafting. Keywords: grafting, cyclic natural rubber, mathylmetacrilate, benzoyl peroxide

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. Keywords: Grafting; inisiator; natural rubber; polymer

The r esearch of grafting methyl methacrylate on to Cycli zed Natural Rubber has been carried out. Dicumyl Peroxide was used as a inisiator and temperature condition at 90 o C with variation of time 1 and 2 hour s . Grafting p rocess was done with technique of reflux in a tree-neck flask with condenser and oil bath. Spectra analysis FTIR performed for determine the presence of graft ed MMA on the backbone of CNR. The results showed that the product CNR-g-MMA was formed with the marked appearance of the absorption peak wave numbers at 1731 cm-1 (carbonyl group absorption) typical for carbonyl (C = O) of met hy l methacrylate. The degree of grafting increased with the increasing time grafting. Keywords: grafting, cyclic natural rubber, mathylmetacrilate, dicumyl peroxide

The purpose of this study was to improve the performance of asphalts as an adhesive in a mixture of asphalt-rubber by using compatibilizer material, graft copolymer natural rubber with glycidyl methacrylate (GMA) (NR-g-GMA). It was carried out the grafting process using Hake’s internal mixer through a melting process in the presence of dicumyl peroxide (DCP). The grafting degree of GMA on natural rubber was determined through acid-base titration and FTIR analysis. The next process was mixed amount of asphalts (100 phr) and NR-g-GMA (5 phr) in an external mixer at 180oC, 600 rpm, for 90 minutes. The mixed asphalts-rubber was characterized its physical properties (penetration, softening point and ductility) and rheology test to determine its resistance of modified asphalts at high temperatures and its crack resistance at low temperatures. FTIR analysis of NR-GMA showed the carbonyl functional group C=O at a wave number of 1730 cm−1 indicating the presence of GMA on NR. The penetration, softening point, and ductility test met the bitumen standards. The rheological test showed that the addition of grafted natural rubber with GMA was able to increase the rutting resistance at high temperature and the crack resistance at high temperature.

The functionalization of cyclic natural rubber (CNR) as compatibilizer with oleic acid (AO) and divinylbenzene (DVB) in variation of dicumyl peroxide has been conducted. Those materials were processed in internal mixer at temperature 160°C with 0.25; 0,50 and 1.00 phr of dicumyl peroxide. The obtained material, CNR-g-AO, was characterized using FT-IR and DSC. The FT-IR spectra showed a signal that specific to the present of C=O around 1737,67 cm−1. An increase in the concentration of dicumyl peroxide increases the grafting degree of monomers onto CNR. The thermal analysis showed the functionalized CNR has different Tg (glass transition temperature) value compared to the neat CNR. These values indicated the successful grafting of oleic acid and divinylbenzene onto CNR.

Free-radical graft co polymerization of acrylic acid and ethyl methacrylate on low-density polyethylene (LDPE) was studied under simulated melt-processing conditions. Initiators benzoyl peroxide and dicumyl peroxide were evaluated for their grafting efficiency. Benzoyl peroxide was found to be an excellent catalyst for the grafting of both monomers, whereas dicumyl peroxide was quite ineffective. Effect of reaction time, initiator concentration, and reaction temperature was studied for benzoyl peroxide initiated graft co polymerization of the two monomers. The changes in the torque and temperature of the reaction melt in the course of the reaction were recorded. More or less quantitative grafting of both monomers could be achieved, using low initiator concentrations, in very short reaction times. The possibility of modifying LDPE during melt extrusion in the extruder itself has been clearly demonstrated. This would be a highly cost-effective way of diversifying the properties and applications of LDPE. Cross linking was found to be relatively higher in the graft co polymerization of acrylic acid but within acceptable limits. Possible mechanisms of this are discussed.

ABSTRACTTo understand the relationship between the initiators and the properties of grafted polypropylene (PP), and provide guidance for designing polymers with different performance through selecting appropriate initiators, a series of styrene (St) grafted PP was prepared by modifying commercial linear PP via reactive extrusion using two different peroxide initiators, dicumyl peroxide (DCP) and benzoyl peroxide (BPO). Fourier transform infrared spectra indicated that the use of DCP led to a higher St grafting degree compared to the system using BPO. The melt flow index and rheological characteristics suggested the existence of short chain branching (SCB) structures in the St grafted PP using DCP, and long chain branching (LCB) structures in the St grafted PP using BPO. Differential scanning calorimetry and polarized optical microscopy results showed that the degradation of the PP chains and the introduction of SCB structures hindered the crystallization process of the St grafted PP using DCP, and the existence of the LCB structures accelerated the crystallization process of the St grafted PP using BPO. We suggest this research can contribute to the understanding of methods to prepare grafted PP with special properties via reactive extrusion by using proper initiators.

Graft copolymerization of polypropylene copolymer (PCP) with maleic anhydride (MA) was studied in melt in Brabender Plasticorder, Twin Screw Extruder by using peroxide initiators, such as benzoyl peroxide (BPO), lauryl peroxide (LPO), luperox-101 (LPU), and dicumyl peroxide (DCP). The variation of MA and initiator concentrations on percent grafting (G), melt flow index (MFI), torque, and gel formation was investigated. Graft copolymers (PgMA and PgMAT) were characterized by FT-IR, DSC, and TGA. Melt flow index increased and torque values decreased with an increase in initiator concentration. The increase in MFI values are in the order: DCP>LUP>BP0>LPO. Maximum chain scission was observed by using DCP and LUP as indicated by their MFI values. The incorporation of MA in PgMA and PgMAT was confirmed by the presence of carbonyl groups at 1712 cm−1 and a shift in crystallization peak temperature from 113 to 123°C due to nucleating effect of the poly(maleic anhydride). The thermal stability was increased by the presence of PgMA. Addition of PgMAT as an additive to PCP, PCP/PP, and amines improves mechanical properties and paintability. Primary amines are more reactive towards PgMAT compared to tertiary amines. *IPCL Communication 350.

Modification has been carried out through a cyclization process using an organic solvent of Xylene in the various of concentration of P2O5 as a Lewis Acid catalyst followed by the grafting process of Maleic Anhydride (MA) monomer using dicumyl peroxide (DCP) as the initiator. The success of the cyclization process of CNR formation can be seen from the FTIR analysis which shows typical peaks at the absorption wave of 741 cm-1 from the CH2 – CH2 cyclical strain vibration and a wavelength of 835 cm-1 from the non-cyclical strain vibration CH2 – CH2 indicating that cyclization has occurred. Furthermore, on the results of grafting, FTIR analysis was carried out to prove that the MA had been grafted on the Cyclic Natural rubber (CNR) so that the formation of CNR-g-MA as shown of the C=O wave number which was on wave number 1710 cm-1 and 1850 cm-1.