/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1016/S0040-6031(01) Thermochimica Acta, 374, 2, pp. 105-114, 2001-07-10 Bitumen microstructure by modulated differential scanning calorimetry Masson, J-F.; Polomark, G. M. Bitumen microstructure by modulated differential scanning calorimetry Masson, J-F. ; Polomark, G. M.A version of this paper is published in / Une version de ce document se trouve dans : Thermochimica Acta, pp. 105-114, v. 374, no. 2, 2001 www.nrc.ca/irc/ircpubs assigned to the maltenes, the other at 70°C to the asphaltenes. The heat capacity of these transitions was found to depend on thermal history. From the total heat capacity, it was calculated that the relative size of the bitumen repeat unit is between 36 and 91 g mol -1 , which given an average molecular weight of 300-1000 g mol -1 for bitumen, translates into a "degree of polymerisation" of ~10. After cooling from the melt and annealing at 22°C, bitumen microstructure was found to develop in three stages. Most rapid is an ordering process that occurs when bitumen is quenched from the melt. It is postulated that this first stage arises from the partial ordering of simple aromatic structures into micro-and nano-phases; a second stage, which ends within ~3h of annealing, relates to the ordering of somewhat larger aromatic structures; and a third stage, which ends in ~16h, is thought to arise from the ordering of the largest bitumen structures, the resins and the asphaltenes. The development of bitumen microstructure and the calculations of the entropy and enthalpy of transitions suggest that bitumen is a multi-phase system with a small crystalline phase, and a large mesophase, i.e, a structured amorphous phase. NRCC-44278

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1021/ef010233r Energy & Fuels, 16, 2, pp. 470-476, 2002-04-01 Time dependent microstructure of bitumen and its fractions by modulated differential scanning calorimetry Masson, J-F.; Polomark, G. M.; Collins, P. Bitumen fractions were analyzed by modulated differential scanning calorimetry (MDSC) before and after annealing at room temperature. MDSC allowed for separating glass transitions (T g 's) from order-disorder transitions. All fractions showed at least two T g 's and different states of order. Saturates were semicrystalline, aromatics were amorphous, resins, and asphaltenes were mesophasic. In bitumen, the fractions order in four stages upon cooling from the melt. In the first stage, all fractions order rapidly into a weakly organized phase. In the second stage, low molecular weight saturated segments crystallize. In the third stage, high molecular weight saturated segments crystallize. In the fourth stage, resins and asphaltenes order into a mesophase. The third and fourth stages are responsible for the room-temperature (steric) hardening of bitumen.

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1021/ef0498667 Energy & Fuels, 19, 1, pp. 120-122, 2005-01-01 Steric hardening and the ordering of asphaltenes in bitumen Masson, J-F.; Collins, P.; Polomark, G. M. Steric hardening and the ordering of asphaltenes in bitumenMasson, J-F.; Collins, P.; Polomark, G. NRCC-47288 AbstractSteric hardening is the hardening of bitumen over time at room temperature. It occurs after bitumen is melted and it often leads to poor reproducibility in standard testing.Modulated differential scanning calorimetry shows that asphaltenes order when bitumen is cooled from the melt and that this phenomenon is time dependent. This communication establishes the link between the ordering of the asphaltenes in bitumen and its steric hardening. It is suggested that at least 24 h elapse between the melting and pouring of bitumen and its subsequent testing by standardized methods.

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1016/j.tca.2005.02.017Thermochimica Acta, 436, 1-2, pp. 96-100, 2005-10-01 Glass transitions and amorphous phases in SBS-bitumen blends Masson, J-F.; Polomark, G. M.; Collins, P. Glass transitions and amorphous phases in SBSbitumen blendsMasson, J-F., Polomark, G.; Collins, P. NRCC-44491 AbstractBlends of bitumen with 3-10% of a styrene-butadiene-styrene (SBS) block copolymer were investigated by means of modulated differential scanning calorimetry (MDSC) in an effort to better understand the miscibility and structure of the blends, along with the composition of the mixed phase(s). This relied on the measurements of the glass transition temperatures (T g ) in bitumen and SBS in their blended and unblended states.In the unblended state, bitumen showed four T g s, and SBS showed two. In the blends, a new T g arose from a phase of mixed composition, which contained polybutadiene (PB) segments and about 30% of the maltenes. The blends also showed anti-plasticization as a shift of the T g s from the paraffins in bitumen and the PB block in SBS moved away from each other. The results indicate that the PB block has good interactions with bitumen, but that the polystyrene (PS) block does not.

Bituminous crack sealants were analyzed by viscometry, fluorescence microscopy, infrared spectroscopy, thermogravimetry, modulated differential scanning calorimetry, and low-temperature tensile testing. The results indicate that sealants are blends of bitumen, oil, copolymer, and filler. Upon blending, these components produce a three-phase system that consists of a polymer-modified bitumen (PMB) matrix, a filler, and a filler-PMB interface. Spectroscopy and microscopy indicate that the PMB phase is rich in styrene-butadiene copolymer, that the filler is recycled rubber, sometimes mixed with calcium carbonate, and that the interface depends on the filler and the oil content in the sealant. The physicochemical methods were used to predict the short- and medium-term performance of sealant mixtures. The short-term performance predicted from viscometry and microscopy correlated well with the 1-year field performance of the sealants. Sealants showed two glass transition temperatures ( Tg’s), and a reasonable correlation was also found between low Tg and medium-term performance in a wet-freeze climate. However, because Tg measurements do not account for stress relaxation and aging effects, correlation was not perfect.