| Elastomer acts an irreplaceable role in daily life, industrial and national defence. Most elastomers, except nature rubber, are fabricated based on petrochemicals which are carbon emissing and nonrenewable.So developing synthetic elastomers from biofuels and bioresources will contribute to the sustainable development of elastomer and the relevant industry. Bio-based engineering elastomer was first proposed by Center of Advanced Elastomer Materials. In order to fufill this concept, in the previous work poly(diisopentyl itaconate-co-isoprene) based on the commodity itaconic acid was synthesed using free radical polymeriziton of di-isopentyl itaconate and isoprene. While the alkoxy length effect of alcohol induced by itaconic acid esterificate reaction on esterification,polymerization, polymer structure and properties, and the nanofiller reinforce properties were not studied. So the present thesis mainly focus on design, preparing, structure and property research of itaconic acid based elastomers with different side chains and the application of these elastomers as well.In the first part of the thesis (Chapter 2), ten kind of stright-chain monoalcohols, which consists the mainly part of biofuel such as biogasoline and biodiesel and eight of them can be extracted from biomass, were used to esterification with itaconic acid. Ten kind of di-n-akyl itaconates monomer were prepared with akyl side chain:di-n-propyl, di-n-butyl, di-n-pentyl, di-n-hexyl, di-n-heptyl, di-n-oxyl,di-n-nonyl, di-n-decyl, dimethy, and diethyl. Di-n-alkyl itaconates with long side chains were synthesized from itaconic acid and higher alcohols by direct esterification using sulfric acid under atomospheric pressure.The yields of them were over 70% except di-n-propyl itaconate with 46%after washed and vacuum distillated. However, the boiling point of ethanol and ethanol are lower than 100 centigrade, and miscrible with water. So the esterification process was renoveted by moleculer sieves to absorp water or using a kattle to improve reaction temperature. The product was distillated in vacuum directly because the mixed product did not delaminate in water. After washed the itaconic anhydride generated during distilation, the yields of dimethyl itaconate and diethyl itaconate were 11.6% and 39.1% by using kattle during esterification.In the second part of the thesis (Chapter 3), isoprene was selected as a comonomer to copolymerize with itaconate in order to offer the crosslink points. Poly(di-n-alkyl itaconate-co-isoprene) (PDAII) was successfully synthesized by redox initiated emulsion polymerization with ten kind of side chains. FTIR and 'H NMR were used to characterise the strucure of PDAII demenstrating that itaconates and isoprene were successfully compolymerized and the deshielding effect of polar ester groups to the end methyl hydrogene was diminished as the alkoxy side chain length increase. The monomer reactivity ratios were measured by Kelen-Tiidos (KT) method in positive and reversed order demenstrated that itaconate with short alkoxyl and isoprene tend to form random polymers and itaconate with long alkoxyl side chain length tend to form gradient copolymers. The glass transition temperatures of PD A?decreased from 15 centigrade to -68 centigrade as the side chain length increase measured by DSC. The thermal degradation temperature of PDAII increased as the side chain length increase measured by TGA. All the PDAIIs were crosslinkable by sulfur, and exhibit elastic properties with high elongation at break and resonse to the original length rapidly when the stress removed.In the third part of the thesis (Chapter 4), physical and mechanical properties were improved by nano silica compared with pure PDAII vulcanizates. The tensile strength of silica/PDB? was 12.3 MPa after reinforced by 50 phr nano silica. The hydrogen bonds between the alkoxy and hydroxyl on the surface of nano silica, which was beneficial to form a uniform disperse of nano silica, were verified by FTIR and low field nuclear magnetic resonance, and density of hydrogen bond decreased as the side chain length increase. The values of loss tangent at 0 0C and 60? are laboratory predictors for tire wet resistance and rolling resistance respectively. The side chain length showed a profound influence to the dynamic mechanic performance of silica/PDAII,including loss tangent at 0 C and 60?. Silica/PDB? exhibited a low loss tangent at 60? and a relatively high value at 0 ?, which means the less energy loss and the satisfactory wet resistance performance of silica/PDBII tread. The free volume of silica/PDAII increased as the side chain length increase which was in line with the glass transition temperature of PDAII.In the fourth part of the thesis (Chapter 5), considering the low hysteresis potential, we designed poly(di-n-butyl itaconate-co-butadiene)(PDBIB) using di-n-butyl itaconate and butadiene. The semi-industrial preparation of two kinds of itaconic acid based elastomer PDBII and poly(di-n-itaconate-co-butydiene) (PDBIB) in 10 liters kettle and their application in tread was studied. The high dispersive silica, the new type of silicane, and a small quantity of butadiene rubber were used in the tread formulation. The mixed compound was modified by in-situ reaction. The tensile strength, modulus at 100% deformation and 300%deformation achieved to 15.OMPa, 2.7MPa and 11.5MPa respectively.The loss tangent at 0 ? and 60? were 0.30 and 0.084 standing for a high wet resistance and a low energy loss. The hydrolytic stability,thermal oxidative aging properties, abrasion resistance, dynamic and thermal-resistance properties were comparable with silica/SSBR.Silica/PDBII tread tire (205/55R16 91H) and silica/PDBIB tire(225/40R18 92W) were manufactured and tested by Linglong Tire Company, Ltd by using MTS tire testing system and the rolling resistance factor were 9.9 kg/t and 7.7 kg/t respectively. The letter factor was rated as "B" level by EU Tyre Label falling the scope of low rolling resistance green tire.In the fifth part of the thesis (Chapter 6), we designed PDBII dielectric elastomer with di-n-butyl itaconate of 70% (PDBII70), 50%(PDBII50), and 30% (PDBII30). The dielectric constant of PDBII70 was 5.68/103Hz after crosslinked by 2.5 phr DCP, which was higher than frequently-used dielectric elastomers such as silicone rubber (2.7) andacrylic rubber (4.8). The tensile strength, dielectric constant and actuated property of PDBII70 were investigated. The highest dielectric actuated strain of PDBII70 was 20% at 30 kV-mm-1 after crosslined by 3.0 phr DCP and 25% at 42kV·mm-1 after crosslinked by 5.0 phr DCP. The actuated properties of PDBII70 were further improved using high-permittivity nano barium titanate ceramics.In the sixth part of the thesis (Chapter 7), we designed poly(diethyl itaconate-co-isoprene) (PDEII) oil resistance elastomer with diethyl itaconate of 80% (PDBII80),60% (PDBII60), 40% (PDBII40) and 20%(PDBII20) using redox initiated emulsion polymerization. After reaction 10 hours, all the elatomer yields were above 75% and the number-average molecular weights were above 140 000. The hydrogen bonds origin between polar alkoxyl groups of PDEII and hydroxyl groups on the surface of nano silica was beneficial to the dispersion of silica. The oil resistance properties of silica/PDEII were tested in 3# oil under different temperatures and immersion time, and compared with silica/NBR 240S. Silica/PDEII80 exhibited better oil resistance than silica/NBR 240S, including tensile strength retention rate, elongation at break retention rate, and volume change. Silica/PDEII60 showed a comparable oil resistance with silica/NBR 240S. |
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