After his assumption to the President of Argentina, Mauricio Macri quickly adopted a series of measures of economic, social and diplomatic reform, showing his different concept and model of governance from previous governments. Affected by this, the bilateral relations between China and Argentina have undergone some notable changes. This article analyzes the development of Sino-Argentine relations in the last two years by dividing it into four phases, making a diagnosis of these changes, and presenting opportunities and challenges that face the relations of both countries. This article argues that the development of the economic and trade relations between China and Argentina has entered a new historical stage and there will be more possibilities for further devel-opment of bilateral cooperation in the future. The diversified cooperation is an indispen-sable way for the two countries to continue to foster bilateral relations, but this requires detailed study and constant innovation in terms of contents, models and mechanisms.

Después de asumir la presidencia de la Argentina, Mauricio Macri adoptó rápidamente una serie de medidas de reforma económica, social y diplomática, mostran-do un modelo diferente de gobernanza en referencia a los gobiernos anteriores. Afecta-das por esto, las relaciones bilaterales entre China y Argentina han experimentado algu-nos cambios notables. Este trabajo realiza un análisis del desarrollo de las relaciones sino-argentinas en los últimos dos años, visualizándolo en 4 fases bien diferenciadas. Este artículo sostiene que el desarrollo de las relaciones sino-argentinas ha entrado en una nueva etapa histórica, con la perspectiva de que siga desarrollándose la cooperación bilateral en el futuro. La cooperación diversificada es una forma indispensable para que los dos países sigan impulsando las relaciones bilaterales, pero requiere el estudio deta-llado y la innovación constante en términos de contenidos, modelos y mecanismos.

Tests of the strain sweep, frequency sweep and stress relaxation for raw natural rubber coagulated by microorganisms (NR-m) and raw natural rubber coagulated by acid (NR-a) were carried out with the use of a rubber process analyzer (RPA). The results showed that the storage torque, complex viscosity of NR-m were higher than those of NR-a while the loss factor was lower. The effect of temperature on viscosity of raw NR was studied following the Arrhenious-Frenkel-Eyring model. The viscous flow behavior of NR-m was poorer than those of NR-a. Furthermore, stress relaxation measurements of raw NR showed a longer period of relaxation for NR-m.