The uncleaved polymer was more viscous because it had more intermolecular forces—both between polymer molecules, and between the polymer molecules and those of the apparatus. Its chains were also more likely to get physically tangled, both upon themselves and with other molecules. These effects increase with longer polymer chains, so the larger the chain (and overall mass), the more viscous the liquid
The uncleaved polymer was more viscous because it had more intermolecular forces—both between polymer molecules, and between the polymer molecules and those of the apparatus. Its chains were also more likely to get physically tangled, both upon themselves and with other molecules. These effects increase with longer polymer chains, so the larger the chain (and overall mass), the more viscous the liquid