Cellulose nanofibre Elastomer NR and SBR based nanocomposites with compatibilisers

Abstract

The thesis describes the utilisation of cellulose nanofibres as newlinereinforcing filler in the development of NR and SBR based composites in newlinethe presence of compatibilisers. Initially, cellulose nanofibres were newlinederived from Coconut spathe, Areca spathe and Pandanus prop root via newlinealkali treatment, bleaching, homogenisation followed by sulphuric acid newlinehydrolysis. It was found that Pandanus prop root fibres gave the highest newlinecellulose content (45 %). A facile method i.e. hydrothermal assisted newlineoxalic acid hydrolysis was also adopted for the isolation of nanofibres. newlineThe nanofibres (PNO) had a uniform diameter in the range of 15-30 nm. newlineNR/PNO and SBR/PNO composites were prepared by latex stage mixing newlineand co-coagulation followed by melt mixing in a Haake internal mixer newlinewith compounding ingredients and then vulcanized. The fibre content was newlinevaried as 0, 1, 3, 5 and 7 phr. Cure characteristics, mechanical, rheological, newlinesolvent barrier and thermal properties of NR/PNO and SBR/PNO composites newlinewith and without bonding agents were evaluated. The bonding agent used for newlinethe study was a mixture of resorcinol and hexamethylenetetramine (RH). newlineAmong NR/PNO composites, the composites containing 5 phr of PNO newlineboth with (NR/PNO5/RH) and without (NR/PNO5) bonding agent displayed newlinesignificant improvement in tensile strength, tear strength, abrasion resistance newlineand solvent barrier properties. Thus NR/PNO5 composite was selected for newlinestudying the effect of compatibilisers. MA-g-NR and ENR were used as the newlinecompatibilisers and was varied from 0-5 phr and 0-3 phr respectively. newlineCompared to NR/PNO5 composite, compatibilised composites with 4 phr newlineMA-g-NR loading exhibited 19 %, 14 % and 5 % increase in tensile newlinestrength, tear strength and abrasion resistance, respectively. In the case of newlineENR compatibilised composites, the one with 2 phr ENR loading showed newlineimprovement in tensile strength, tear strength and abrasion resistance newlineby 17 %, 30 % and 5 %, respectively. The solvent resistance improved newlinecompared to gum vulcanizate.