Directly after the milling process the temperature inside the grinding vessel is measured to confirm that the temperature is below 90 °C and no Maillard reaction as well as no following reactions like dehydration of sugars to furfural and hydroxymethylfurfural occurs. In a first experiment without acid impregnation the influence of ball milling towards the crystallinity of cellulose was determined by milling for 86 min followed by a XRD-measurement to verify the amorphization while milling. Therefor a Bruker D2 Phaser 2nd Generation was used with a wavelength of Cu Kα =1,5406 𝐴 . The measurements were taken in a 2-theta range from 8 ° to 60 ° with a measurement speed of 0,239 °•(1.1 s) -1 using a background-free silicon sample holder. After mechanocatalytic partial depolymerization the amount of product equal to a mass of 400 mg without acid load was weighed in and stirred with 40 g demineralized water at room temperature respectively 100 °C (Fraunhofer IWKS). Afterwards the insoluble fraction was filtered off, dried under vacuum at 40 °C overnight and weighed in again to determine the mass of the insoluble fraction. The filtrate was analyzed by HPLC (Agilent 1260 Infinity equipped with a HPX-87H-column at a flow rate of 0.5 mL•min -1 at 60 °C). Additionally precipitation and purification was performed as reported by Wolf et al. for the experiments at Fraunhofer IWKS. GPC-measurements of the samples after milling were taken to determine the molecular weight distribution of the soluble fraction. For samples with cellulose as substrate a PSS Suprema column at a flow rate of 1 mL•min -1 0.05 % NaN3 at 25 °C was used. The lignocellulosic samples were measured with a MCX 1000A column with a mixture of 0.1 mol•L -1 NaOH and 0.1 mol•L -1 NaCl at the same flow rate. At Fraunhofer IWKS SEC-MALS was performed using an Agilent 1260 Infinity II HPLC system combined with an Optilab and Dawn 8 detector (both Wyatt Technology Europe GmbH) A PSS Suprema column with a flow rate of 0.8 mL min -1 100 mM NaNO3/0.05% NaN3 at 30°C was used.