We report synthesis of a high-strength renewable phenolic composition with linear large deformation strain without a thermoplastic-like yielding while retaining thermal processability. Small molecule carboxylic acid derivatives with varying molecular architectures act as esterifying crosslinkers in an equal mass mixture of lignin and acrylonitrile–butadiene copolymers in a highly scalable, solvent-free process. These “inverse thermoplastic vulcanizates” (iTPVs)unique in their approach of crosslinking the rigid lignin phase rather than the soft phaseexhibit ordered self-assembly, tunable nanoscale morphology, and processability. The first of its kind iTPV compositions exhibit engineering stress–strain curves with two- to sixfold linear extensibility, a twofold rise in strength, and an order of magnitude enhanced modulus compared to a simple lignin-rubber blend. Viscoelastic properties correlate well with crosslinker architecture and the resulting morphology, allowing competing properties of toughness and stiffness to be tuned. This research finds a path for identifying the potential of lignin as a sustainable feedstock.

In this article, we present new methods to improve the adhesion between poly(paraphenylene terephthalamide) fibers and a natural rubber for tire reinforcement. Fiber pretreatments are applied to create new surface morphologies on the fiber that enables enhanced adhesion between the fiber and rubber matrix. The pretreated fibers are then subject to treatments with coupling agents in the presence of supercritical carbon dioxide (scCO2) in an attempt to permeate the fiber surface and chemically bind the fiber to the rubber matrix. Shear lag analysis using a Kelly Tyson approach is compared to more refined models to evaluate optimum test parameters for fiber pull‐out adhesion tests. The results show that the adhesion increases by approximately 100% when compared to conventional composites. Failure analysis of fiber surface reveals a suppression of interfacial failure. The effects of pretreatments on fiber properties are also characterized, and the optimization between fiber properties, fiber–matrix interface properties, and overall composite properties are discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45520.

No abstract

No abstract