Handsheets of grammage 70 g/m² with 20% PCC as filler, 0.2% & 0% carrageenan as additive at different Al₂(SO₄)₃ dosages were prepared.

<p>A) and B) are, respectively, tensile and bursting indices as a function of Al₂(SO₄)₃ dosage; C) is PCC retention as a function of Al₂(SO₄)₃ dosage.</p

Handsheets of grammage 70 g/m² with 20% PCC as filler at different additive dosages were prepared.

<p>A) and B) are, respectively, the tensile and bursting indices as a function of additive dosage; C) is PCC retention as a function of additive dosage.</p

General Silver-Catalyzed Hydroazidation of Terminal Alkynes by Combining TMS‑N₃ and H₂O: Synthesis of Vinyl Azides

A general hydroazidation of unactivated alkynes using silver catalysis is reported. The reactions of diverse terminal alkynes with trimethylsilyl azide (TMS-N3) in the presence of H2O afforded the corresponding vinyl azides in good to excellent yields. This reaction has a broad substrate scope, good functional group tolerance, simple operation, and high reaction efficiency, thus providing an easy access to various functionalized vinyl azides

Handsheets of grammage 70 g/m² with 20% PCC as filler, 0.03% CPAM as an additive at different carrageenan dosages were prepared.

<p>A) and B) are, respectively, tensile and bursting indices as a function of carrageenan dosage; C) is PCC retention as a function of carrageenan dosage.</p

SEM images of handsheets without and with 0.2% carrageenan.

<p>SEM images of handsheets without and with 0.2% carrageenan.</p

Carrageenan as a dry strength additive for papermaking

<div><p>Carrageenans are commercially important sulfated gums found in various species of red seaweeds (Rhodophyta), wherein they serve a structural function similar to that of pectins in land plants. In this study, carrageenan was used independently or in combination with cationic polyacrylamide (CPAM) and/or Al₂(SO₄)₃ to explore its application as a dry strength additive in papermaking. Strength index determination, ash content detection, FTIR characterization and SEM observation were performed on prepared handsheets. The results showed that with 0.6% Al₂(SO₄)₃ and 0.2% carrageenan as additives, the tensile index increased by 13.53% and precipitated calcium carbonate (PCC) retention increased by 57.06%. With 0.6% Al₂(SO₄)₃, 0.2% carrageenan and 0.03% CPAM as additives, PCC retention increased by 121% while the tensile index did not fall compared to handsheets without additives, indicating that carrageenan could enhance the strength of handsheets and be used as an anionic dry strength agent.</p></div

Handsheets of grammage 70 g/m² at a PCC addidtion level of 20%, with Al₂(SO4)₃ 0.6%, carrageenan 0.2% and CPAM 0.03% as additives and without additive were prepared.

<p>A) and B), respectively, are tensile index and PCC retention of different handsheets.</p

Dynamic drainage tests were performed at a volume of 500 ml of 0.3 w% fibres and 0.13 w% PCC in water.

<p>Absorbance of filtrate and drainage speed are functions for Al₂(SO₄)₃ dosage.</p

Pooled associations between VDR expression and patient prognosis.

Pooled associations between VDR expression and patient prognosis.</p

FTIR spectra of Handsheets of grammage 70 g/m² with 20% PCC as filler.

<p>A) is spectrum of handsheet with no additive, B) is spectrum of handsheet with carrageenan dosage of 0.2%.</p