  We report new lightcurves and phase functions for nine Jupiter-family comets
(JFCs). They were observed in the period 2004-2015 with various ground
telescopes as part of the Survey of Ensemble Physical Properties of Cometary
Nuclei (SEPPCoN) as well as during devoted observing campaigns. We add to this
a review of the properties of 35 JFCs with previously published rotation
properties.
  The photometric time-series were obtained in Bessel R, Harris R and SDSS r'
filters and were absolutely calibrated using stars from the Pan-STARRS survey.
This specially-developed method allowed us to combine data sets taken at
different epochs and instruments with absolute-calibration uncertainty down to
0.02 mag. We used the resulting time series to improve the rotation periods for
comets 14P/Wolf, 47P/Ashbrook-Jackson, 94P/Russell, and 110P/Hartley 3 and to
determine the rotation rates of comets 93P/Lovas and 162P/Siding-Spring for the
first time. In addition to this, we determined the phase functions for seven of
the examined comets and derived geometric albedos for eight of them.
  We confirm the known cut-off in bulk densities at $\sim$0.6 g
$\mathrm{cm^{-3}}$ if JFCs are strengthless. Using the model of Davidsson
(2001) for prolate ellipsoids with typical density and elongations, we conclude
that none of the known JFCs require tensile strength larger than 10-25 Pa to
remain stable against rotational instabilities. We find evidence for an
increasing linear phase function coefficient with increasing geometric albedo.
The median linear phase function coefficient for JFCs is 0.046 mag/deg and the
median geometric albedo is 4.2 per cent.
