Supramolecular elastomers (SESis) were synthesized via a simplified synthesis route on the basis of a linear bifunctional polydimethylsiloxane. Compared with previous synthesis methods, the structure of the product was much clearer. The ¹H-NMR titration results show that the hydrogen-bond associations in SESis were relatively weak. During ¹H-NMR reaction monitoring, the viscosity analysis of SESis and the model reactions demonstrated a previously neglected covalent crosslinking reaction not only during the reaction process but also during the postprocess; this led to a hybrid network, that is, covalent crosslinking and hydrogen association, in SESis. This finding explained the poor solubility of the SESis, and it provides us with an important way to controllably synthesize this material and adjust its properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43385.

Novel self-healing supramolecular elastomers based on polydimethylsiloxanes (SESi) were synthesized from a mixture of polydimethylsiloxanes derivers with single, di-, or tri-carboxylic acid groups (PDMS–COOH_x, where x = 1, 2, and 3, respectively), diethylene triamine, and urea with a two-stage procedure. The reactions and the final products were tracked, characterized, and confirmed by Fourier transform infrared spectroscopy, ¹H-NMR, differential scanning calorimetry, dynamic mechanical analysis, and gel permeation chromatography. Compared with a supramolecular rubber based on dimer acid (reported previously) with a similar synthesis procedure, the SESi showed a lower glass-transition temperature of about −113°C for the softer chain of polydimethylsiloxane and showed real rubberlike elastic behavior and self-healing properties at room temperature or even lower temperatures. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Blends of poly(ethylene-co-vinyl alcohol) (EVOH) with maleic anhydride-grafted-poly(ethylene-octene) (POE-g-MAH) were prepared by blending extrusion in order to improve the toughness and flexibility of EVOH. The compatibility behavior of these blends with POE-g-MAH content range from 0 to 25 wt% was studied using mechanical, thermal, infrared, and morphology characterization techniques. The mechanical test results showed that POE-g-MAH can significantly improve the impact toughness of EVOH with a brittle-tough transition appeared at the POE-g-MAH content of 20 wt%. A huge increase of toughness of the blend was also observed when the POE-g-MAH content was increased to 15 wt%. The thermal analysis of the blends demonstrated that the thermal stability of EVOH is improved with the addition of POE-g-MAH, adding 20 wt% or more POE-g-MAH can effectively decrease the crystallinity of EVOH and greatly improve compatibility between the two components. The existence of esterification between anhydride groups in POE-g-MAH and hydroxyl groups in EVOH in melt processing was confirmed using Fourier transform infrared technique. Morphology analysis of the Izod impact fractures has clearly shown the mechanisms for these blends to change from brittle to tough with increasing the POE-g-MAH content. POLYM. ENG. SCI., 53:2093–2101, 2013. © 2013 Society of Plastics Engineers

Ten types of rare earth (RE) compounds modified carbon black (HAF-RE) were prepared using chemical-deposit method, then HAF-RE were mixed with natural rubber latex to prepare HAF-RE filled powdered natural rubber [P(NR/HAF-RE)] by a carbon black/rubber latex coagulation method. It is found that most of the P(NR/HAF-RE) vulcanizates showed better mechanical properties, especially higher tensile modulus, and tensile strength, compared with none-rare earth modified carbon black filled powdered natural rubber [P(NR/HAF)]. Dysprosium (Dy) modified carbon black (HAF-Dy) filled powdered natural rubber [P(NR/HAF-Dy)] was chosen for intensive investigation because of its better comprehensive mechanical properties. It is found that the adding of Dy compounds could help to get smaller particles with narrower particle size distribution, and results from the SEM analysis show that carbon black has been dispersed in rubber matrix uniformly with diameter of 50–150 nm. The TEM analysis showed that Dy compounds could obviously reduce the aggregation of primary particles of carbon black, and promote the dispersion of carbon black in P(NR/HAF-Dy) particles. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci 2008

Powdered carbon black filled natural rubber, P(NR/HAF), is a premixture of natural rubber and carbon black in powdered form with good carbon black dispersion throughout the rubber matrix. In this study, the mastication properties of P(NR/HAF) were observed under a wide temperature range (50–110°C) and rotor speed (30–100 rpm) range, using a mixing head attached to Brabender Plasticorder. It was found that P(NR/HAF) showed different mastication characteristic, compared to the traditional internal mastication theories of natural rubber; poor masticating properties of P(NR/HAF) are observed with low rotor speed and high temperature and a ‘‘stable zone’’ with middle rotor speed and lower temperature. The Mooney viscosity of rubber batch under different rotor speed and temperature was almost the same, and mastication properties were unsatisfactory. It was considered that the higher temperature build-up of the mixing batch of P(NR/HAF) during the early stage of internal mixing results in the special mastication properties. A quadratic mastication model of P(NR/HAF), based on the multivariate regression analysis and stepwise regression analysis, was used to predict the mastication characters of P(NR/HAF) in internal mixer under varied temperature and rotor speed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers