Publication: Effect of different type of coagulants and serum ph on the properties of natural rubber compounds and vulcanizates
| datacite.subject.fos | oecd::Engineering and technology::Materials engineering | |
| dc.contributor.author | Ng Jing Wei | |
| dc.date.accessioned | 2025-04-29T07:00:51Z | |
| dc.date.available | 2025-04-29T07:00:51Z | |
| dc.date.issued | 2023-07-01 | |
| dc.description.abstract | Natural rubber (NR) is the main component used in tyre industry that is extracted naturally from Hevea Brasiliensis in latex form and further transformed into dried rubbersheet. In the first experiment, the latex was coagulated with different types of coagulant, which are formic acid, sulfuric acid, CaCl2, methanol and spontaneously without addition of coagulant. After processing, the raw rubbers produced from the respective coagulants were subjected to different testing from the perspective of coagulation process, raw rubber, masterbatch, final mix compound and finally vulcanizate in tyre tread formulation. Being the most efficient coagulant, sulfuric acid displayed poorer properties in raw rubber with oxidized rubber sheets and higher amount of short rubber chains as indicated in AE content and Mw. In contrast, natural coagulation was demonstrated to be least efficient, but the raw rubber was tested to have highest molecular weight and macrogel content. The Mw of raw rubber and macrogel content were shown to be well correlated to the VR and P0. Besides, the selection of coagulant type was found to have impact also on the N and metal ions content of raw rubber. However, the impact of coagulant type on the BdR of masterbatch, Payne effect and VR of final mix compound was indirect depending on the Mw and VR of raw rubber. Accelerating effect of natural proteins and retarding effect of sulfuric acid were also observed in curing properties. The physical mechanical properties of vulcanizate were mainly influenced by the crosslink density of vulcanizate. The type of coagulants used displayed no significant influence on the wet grip and rolling resistance properties of vulcanizate. In the second experiment, the latex was coagulated with formic acid and sulfuric acid respectively, in serum pH 4 and pH 2. The most notable impact of serum pH was the efficiency of coagulation process, VR and P0 of raw rubber. It was shown that the impact of acid type on the raw rubber properties was less important if the serum pH was controlled on same level except PRI. However, the impact of serum pH on other properties of raw rubber were not significantly observed. After addition of compounding ingredients, the properties of masterbatch, final mix compound and vulcanizate displayed no significant differences between different serum pH suggesting the compounding ingredients play more important role to decide the properties of vulcanizate. | |
| dc.identifier.uri | https://erepo.usm.my/handle/123456789/21465 | |
| dc.language.iso | en | |
| dc.title | Effect of different type of coagulants and serum ph on the properties of natural rubber compounds and vulcanizates | |
| dc.type | Resource Types::text::thesis::master thesis | |
| dspace.entity.type | Publication | |
| oairecerif.author.affiliation | Universiti Sains Malaysia |