Low molar mass polybutadiene made crosslinkable by the introduction of silane moieties via urethane linkage: 2. Crosslinking study

• Published in: Polymer (Guilford) Vol. 39; no. 4; pp. 973 - 979
• Main Authors: Schapman, F., Couvercelle, J.P., Bunel, C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.1998; Elsevier
• Subjects: Applied sciences; Chemical reactions and properties; crosslinking; Crosslinking, vulcanization; Exact sciences and technology; mechanical properties; Organic polymers; Physicochemistry of polymers; polybutadiene; silane; swelling; polybutadiene; swelling; silane; crosslinking; mechanical properties; Catalytic reaction; Humidity effect; Butadiene polymer; Telechelic polymer; Temperature effect; Crosslinking; Organic silane; Kinetics; Tin Organic compounds; Experimental study; Organic carbamate
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/S0032-3861(97)00355-8

In the present paper we discuss the crosslinking of polybutadiene bearing alkoxy silane functions (PBU nSi), where n is the number of silanes per chain ( n = 1.2, 2, 2.4). Crosslinking was carried out at different temperatures, with and without a catalyst. The best experimental conditions correspond to 80°C, under moisture with dibutyl tin dilaurate as the catalyst in the ratio of [DBTL]/[Si] = 5 × 10 −3. The reaction was followed by the measure of swelling ( Q) in toluene and mechanical parameters (storage modulus ( E′), E′ at rubbery plateau and tan δ). The low rate of modification, essentially at chain extremities, leads to the molar mass per crosslinked unit ( Mc ) being practically constant and thus to a weak increase of T g whatever the n value. Only a drop of damping efficiency is observed during the crosslinking process.