Effects of hydrocarbon tackifiers on the adhesive properties of contact adhesives based on polychloroprene - III. The effect of the molecular weight of the tackifier

• Published in: Journal of adhesion science and technology Vol. 11; no. 10; pp. 1303 - 1319
• Main Authors: DEL PILAR FERRÁNDIZ-GÓMEZ, Teresa, Fernández-García, Juan C., CÉSAR ORGILÉS-BARCELÓ, A., Martín-Martínez, José Miguel
• Format: Journal Article
• Language: English
• Published: Leiden Taylor & Francis Group 01.01.1997; Brill
• Subjects: Application fields; Applied sciences; Exact sciences and technology; hydrocarbon resin; molecular weight; Polychloroprene; Polymer industry, paints, wood; rheology; T-peel strength; tack; tackifier; Technology of polymers; thermal mechanical analysis; Tackifying resin; Adhesivity; Tack; Peel strength; Mechanical properties; Surface properties; Tensile property; Chloroprene polymer; Experimental study; Adhesive; Property formulation relationship; Styrene copolymer
• ISSN: 0169-4243; 1568-5616
• DOI: 10.1163/156856197X00156

Aromatic hydrocarbon resins with different molecular weights (M w = 1300-50400 daltons) were added to a solvent-based polychloroprene adhesive. The hydrocarbon resins were characterized using infra-red (IR) and differential scanning calorimetry (DSC) measurements. The properties and compatibility of the polychloroprene/resin blends were studied using mechanical tests, DSC measurements, scanning electron microscopy (SEM), and stress-controlled rheology. Tack measurements were also carried out and the adhesion strength was obtained from T-peel tests on roughened styrene-butadiene rubber/polychloroprene adhesive joints. The addition of low-molecular-weight tackifiers produced a compatible polychloroprene/tackifier system (only one T g was found in DSC measurements), while the addition of a high-molecular-weight (and broad molecular weight distribution) tackifier produced a partially incompatible system (two Tg's were found in DSC measurements). The compatibility of polychloroprene/tackifier blends was also assessed with stress-controlled rheology and SEM. An increase in the T-peel strength and tack were produced when the molecular weight of the tackifier increased, although the addition of a hydrocarbon resin with a M w higher than about 50 000 reduced the tack. A broad molecular weight distribution in the tackifier favoured incompatibility with the polychloroprene, resulting in a reduction in the tack and rheological properties.