摘要:

AbstractCrystals of amylose acetate have been grown by film formation method of crystal growth. Isolated fibres and fibres present in spherulites showed characteristic twisting and branching habit. Etching of the crystals reveals that some features are observed in a film, and that they are mainly associated on the surface of a film. Various growth stages have been obtained simply by varying concentration of polymer solution at constant temperature. Presence of linkages is found in fibrillar as well as lamellar crystals. Linkages are clearly observed in all growth stages indicating that they may be due to typical growth of features. Evidence obtained for several polymers indicate that linkages are the characteristics of structures grown from concentrated solution as well as from melt. The concentration and location of intercrystalline linkages can be considered to have profound effect on physical properties of polycrystalline material.

ISSN:0038-9056    

DOI:10.1002/star.19760280902

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractQuantitative Determination of Substituents of Starch Derivatives by means of Infra‐Red Spectroscopy. A process for the infra‐red spectroscopic quantitative determination of the degree of substitution of starch derivatives was developed which may be carried out rapidly. Film technique with the use of an inner standard proved most suitable for this process. Strips of starch films were measured in the IR‐Spectral photometer. If the C=O‐band is characteristic for the starch derivative it is sufficient to record the part spectrum from 2200 to 1500 cm−1. The newly developed process shows good reproducibility and offers a suitable alternative to the chemica

ISSN:0038-9056    

DOI:10.1002/star.19760280903

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractCationic dialdehyde starch (DAS) dispersions have been prepared in water at 15% concentration by a new cooking procedure. A stable fluid form of cationic DAS, a wet‐ and dry‐strength agent for paper, should facilitate commercial use. Cationic DAS dispersions of pH 3.0 stored in polyethylene containers at 25°C or below were unchanged after 6 months; other storage conditions were also evaluated. An unexpected benefit of the new preparative conditions was a 40% reduction of cationizing agent, betaine hydrazide hydrochloride, without loss of effectiveness. Further savings may be possible by blending cationic DAS with unmodified starch; wet‐ and dry‐strength improvements were maintained in paper with a blend containing 33% unmodified starch and 67% cati

ISSN:0038-9056    

DOI:10.1002/star.19760280904

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractHot acetylation of maltotriose with acetic anhydride and sodium acetate led to the formation of an anomerically unsubstituted maltotriose decaacetate (2.8% yield) in amorphous form in addition to the principal product, β‐maltotriose hendecaacetate (80% yield). The structure of the decaacetate was elucidated by chemical reactions and n.m.r. spectroscopy. α‐Maltotriose hendecaacetate and deca‐O‐acetyl‐α‐maltotriosyl chloride were prepared to facilitate the structural assignment. From measurement of the optical rotation, it was assumed that the decaacetate is a mixture of both anomers in a constant proportion. The decaacetate was also obtained either by treatment of the β‐hendecaacetate with hydrogen bromide in acetic acid followed by warm aqueous sodium acetate or by the reaction of the β‐hendecaacetate with piperidin

ISSN:0038-9056    

DOI:10.1002/star.19760280905

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractA method is described for the separation and analysis of oligosaccharides by gel chromatography, using Bio‐Gel P‐2, 200–400 mesh and Bio‐Gel P‐4, 200–400 mesh. Resolution of malto‐oligosaccharides containing up to 13 glucose residues was obtained on both the P‐2 and the P‐4 columns. This resolution is slightly lower than that obtainable using the finer minus 400 mesh gel. However, when the two columns were connected in series, resolution of oligomers containing up to 15 glucose residues was obtained. This resolution is comparable to that obtainable on a single P‐2 minus 400 mesh column. Improved resolution of lower oligomers was obtained by recycle gel chromatography on the P‐2 column. Some of the practical difficulties associated with the operation of a minus 400 mesh gel column were avoided as high pressure is not required to operate the 200

ISSN:0038-9056    

DOI:10.1002/star.19760280906

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

摘要:

AbstractMechanical Dust Separators. Due to the Federal Governments issue of its General Administrative Regulation (Technical Instruction for the Preservation of Air Purity — TA‐Luft of August 28, 1974) the dust extraction plant has gained special significance as the limitation of solid matter emission is part of the authorization process for installing a dryer. The present paper deals with the dust extraction systems which today's technology places at dispo

ISSN:0038-9056    

DOI:10.1002/star.19760280907

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19760280908

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19760280909

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19760280910

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY

ISSN:0038-9056    

DOI:10.1002/star.19760280912

出版商:WILEY‐VCH Verlag GmbH    

年代:1976

数据来源: WILEY