Search results for "moolimassa"
showing 3 items of 3 documents
Role of lignin and sodium carbonate on the swelling behavior of black liquor droplets during combustion
2018
AbstractA partial removal of lignin from black liquor (BL) by carbonation and lignin precipitation was studied. In lignin-lean BL droplets during combustion in a laboratory furnace at 800°C in stagnant air, the maximum swelling was decreased. This observation was interpreted as showing that the lignin content decrement is due mainly to removal of higher molar mass (HMM) lignin and that the Na2CO3content of the BL is increased. Stepwise precipitation experiments with industrial softwood and hardwood kraft BLs by carbonation (resulting in pH decrement from 13 to 9) indicated that a fraction of HMM lignin (MM >10 kDa) with a higher amount of carbohydrates precipitated more prominently and e…
Chemometric Study on Alkaline Pre-treatments of Wood Chips Prior to Pulping
2016
Alkaline pre-treatments were performed for the production of organics-containing effluents from silver/white birch (Betula pendula/pubescens) and Scots pine (Pinus sylvestris) chips prior to chemical pulping. Pre-treatment conditions were varied with respect to time (from 30 min to 120 min), temperature (130 °C and 150 °C), and alkali charge (1, 2, 3, 4, 6, and 8% of NaOH on oven-dried wood). The analytical data (total content, weight average molar mass, and molar mass distribution) on dissolved lignin were subjected to principal component analysis to examine the relationship between molar mass and molar mass distributions in lignin removed from different wood species under varying alkaline…
Polypropeenin fysikaalisten ominaisuuksien muutokset ekstruusioprosessissa
2013
Changes in mechanical properties and reasons for twisting behaviour of thermoformed polypropylene lids is studied. The study is based on the investigation of changes in molecular weight distribution and crystallinity of isotactic polypropylene during extrusion process with different process parameters. Also the effect of additives and re-grinded material is studied. Gel permeation chromatography (GPC) was used in measurements of molecular weight distributions and crystallinities of polypropylene was measured with differential scanning calorimetry (DSC). Process parameters don't have any effect on mechanical properties of the lids but twisting behaviour diminish considerably by changing the …