Rubber Science

WATER RESISTANT STARCH XANTHIDE FILLED NATURAL RUBBERResearch Articles
Pages 28 - 42
P. Chuoy-Plong & C. Hepburn
- Abstract
- Keywords
Starch xanthide-natural rubber latex masterbatching process was studied starting from both latex concentrate and fresh field latex. Masterbatches of varying starch xanthide content were prepared. Physical properties of the compounds containing various starch xanthide loading were investigated both before and after exposure to water. The use of mercapto silane (Silane A 189) coupling agent in starch xanthide filled natural rubber was examined with the intention of reducing its water sensitivity. It was concluded. that vulcanizates containing Silane A 189 have significantly improved physical properties in both dry and wet states and have substantially lower water sensitivity.

Natural rubber, Starch xanthide, Reinforcement, Coupling agent, Water resistance, Silane

RESOURCE USE IN RUBBER SMALLHOLDINGSResearch Articles
Pages 43 - 49
Toms Joseph & V. Haridasan
- Abstract
- Keywords
The extent and pattern of resource use of small growers during the immaturity period in relation to the levels of external funding and asset holdings were studied. The study revealed that the institutional funds were able to fill up to a certain extent the resource gap caused by the lower levels of asset holdings. It was also seen that as the size of the holding increased, the impact of institutional funds on resource use declined.

Natural rubber, Institutional finance, Asset holding, Resource use, Smallholding, India

THE IMPACT OF BRADYRHIZOBIUM INOCULATION ON NODULATION, BIOMASS PRODUCTION AND NITROGEN FIXATION IN PUERARIA PHASEOLOIDESResearch Articles
Pages 50 - 54
R. Kothandararnan, Jacob Mathew, Kochuthressiamma Joseph & K. Jayarathnam
- Abstract
- Keywords
The population of Bradyrhizobium which could nodulate Pueraria phaseoloides in acid soils was observed to be very low. The effectiveness of nodules produced by P. phaseoloides was also found to be low. Inoculation of P. phaseoloides seed with six selected bradyrhizobial isolates increased nodulation, biomass production, nitrogenase activity and spread of the cover crop. However, only two isolates showed prolonged effect. The total N in soils under cover crop inoculated with different bradyrhizobial isolates did not show any variation.

Pueraria, Bradyrhizobium, Biomass, Nitrogenase

INVESTIGATIONS ON THE REINFORCEMENT MECHANISM OF SILICA FILLED EPOXIDISED NATURAL RUBBER A DYNAMIC MECHANICAL APPROACHResearch Articles
Pages 55 - 62
Susy Varughese & D. K. Tripathy
- Abstract
- Keywords
50 mol per cent epoxidised natural rubber (ENR 50) was evaluated for its chemical interaction characteristics with precipitated silica with the help of rheometric studies and dynamic mechanical analysis. Isothermal dynamic mechanical properties were also studied for silica filled ENR in the presence of a silane coupling agent. Chemical interaction between silica and ENR was found to be high in the absence of any conventional curing aids.

Epoxidised natural rubber, Silica, Chemical interaction, Dynamic mechanical properties

MODIFIED NATURAL RUBBER AS A TYRE CORD - RUBBER BONDING AGENTResearch Articles
Pages 63 - 70
A. K. Mukherjee, S. H. 0. Egboh, Barun K. Samui, Arup K. Chandra & R. Mukhopadhyay
- Abstract
- Keywords
Natural rubber grafted with glycidyl methacrylate (GMA) in toluene, is attempted for bonding both polyamide and polyester tyre cords to rubber. Effect of total dose of y-irradiation and concentration of GMA on grafting is discussed. Grafting of NR with GMA reduces thermal stability. However, initial decomposition temperature is well above the normal curing temperature (> 200°C). Adhesion is increased by approximately 40 per cent with nylon-6 and 50 per cent with polyester and nylon - 66.

Natural rubber, Nylon, Polyester, Glycidyl methacrylate, Grafting efficiency, Adhesion

NATURAL RESISTANCE OF RUBBER WOOD TO MARINE BORERS AND A PRELIMINARY NOTE ON THE EFFECT OF PRESERVATIVE TREATMENTResearch Articles
Pages 71 - 74
K. Satyanarayana Rao, L. N. Santhakumaran, M. Balaji & V. V. Srinivasan
- Abstract
- Keywords
Results of exposure tests carried out on rubber wood at 3 Indian ports (Visakhapatnam and Krishnapatnam on the east coast and Goa on the west coast) are reported. While untreated panels were tested at all the harbours, panels treated with CCA and CCB preservatives were tested at Visakhapatnam and Krishnapatnam. The results indicate that rubber wood is highly perishable in untreated condition, having been completely destroyed by marine borers in only 4-6 months. Treated panels fared well having undergone only negligible attack even after 24 months of exposure and are continuing in the field. This study indicates that rubber wood could be suitably upgraded with preservative treatment to find application even in the rigorous marine environment. Further tests are, however, necessary.

Hevea brasiliensis, Natural durability, Preservative treatment, CCA, CCB, Marine borers