Abstract

Many products that directly impact the quality of human life today — gloves, catheters, condoms, and baby bottle teats — are made through the latex-dipping technology. While a variety of methods have been developed – e.g., particle counting, turbidimetry, microscopy, and light scattering – which are suitable for studying the coagulation of latex at very low concentrations, much less work has focused on methods suitable for in-situ characterization of latex coagulation in concentrated solutions (e.g., as relevant to the dipping process). This paper presents a process-relevant rheological protocol for assessing and optimizing latex coagulation dynamics for the thin glove coagulant dipping process. The method involves, first, the use of small amplitude oscillatory rheology to characterize the time-dependent evolution of the viscoelastic properties (e.g., dynamic moduli and phase angle), to quantify the coagulation kinetics. Second, the percolated latex film (after coagulation) is assessed by compressional rheology to evaluate the thickness and elastic modulus. The protocol is herein demonstrated using a commercial-grade carboxylated butadiene-acrylonitrile copolymer (XNBR) latex and nitrate-based coagulant solutions containing various counterions such as calcium, magnesium, aluminum, sodium, and ammonium ions. The results show that the method is sensitive to small changes in ionic speciation, concentration of coagulant formulations, and small changes in temperature. Hence, it can be applied to assess and optimize latex-coagulant formulations and processing parameters for the latex dipping process. While the protocol is demonstrated for an XNBR latex system, its extension to other latex chemistries may require system-specific calibration.

Department(s)

Chemical and Biochemical Engineering

Publication Status

Full Text Access

Comments

University of California, Los Angeles, Grant None

Keywords and Phrases

Coagulant formulation; Coagulation kinetics; Latex dipping; Nitrate salts; Nitrile butadiene rubber; Rheology

International Standard Serial Number (ISSN)

1873-4359; 0927-7757

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Elsevier, All rights reserved.

Publication Date

20 Jun 2026

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