scholarly journals The Influence of Monomer Composition and Surface-CrossLinking Condition on Biodegradation and Gel Strength of Super Absorbent Polymer

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 663
Author(s):  
Jung Soo Kim ◽  
Dong Hyun Kim ◽  
Youn Suk Lee
Keyword(s):  
Treatment Time ◽  
Gel Strength ◽  
Control Group ◽  
Cellulose Content ◽  
Retention Capacity ◽  
Super Absorbent Polymer ◽  
Monomer Composition ◽  
Cellulose Hydrogel ◽  
Improved Performance ◽  
Absorbent Polymer

In this study, a superabsorbent polymer (SAP) comprising poly (IA-co-cellulose-co-VSA-co-AA; ICVA) core-SAP (CSAP) was synthesized through radical polymerization using itaconic acid (IA), acrylic acid (AA), cellulose, and vinyl sulfonic acid (VSA) as monomers. The absorption performances and relative biodegradability of various compositions prepared by adjusting the amounts of cellulose and VSA with constant IA and AA content were compared. Increasing the cellulose content in CSAP contributed to improved biodegradation of the surface-crosslinked SAP (SSAP) and gel strength, although the free absorbency (FA) and centrifuge retention capacity (CRC) decreased. Increasing the VSA content resulted in strong anionicity, which enables the absorption of large amounts of water. Surface-crosslinking technology was applied to the CSAP synthesized with the optimal composition ratio to increase its absorption performance and gel strength. Improved performance of the synthesized SSAP (a CRC of 30.4 g/g, absorbency under load (AUL) of 23.3 g/g, and permeability of 55 s) was achieved by selecting the optimal surface-crosslinking treatment time and the amount of distilled water in the surface-crosslinking solution: as the latter was increased in the surface-crosslinking solution, the AUL and permeability of the SSAP were improved, and its biodegradability was found to be 54% compared to the 100% biodegradable cellulose hydrogel in the control group.

Preparation of Super Absorbent Polymer by Carboxymethyl Cellulose Grafting Acrylic Acid Using Low-Temperature Plasma Treatment

2011 ◽  
Vol 239-242 ◽  
pp. 2578-2583
Author(s):  
Li Jie Huang ◽  
Ting Xu ◽  
Hong Tao Wang ◽  
Shuang Fei Wang
Keyword(s):  
Acrylic Acid ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Super Absorbent Polymer ◽  
Grafting Reaction ◽  
Vacuum Degree ◽  
Plasma Treatment Time ◽  
Absorbent Polymer

Carboxymethyl cellulose (CMC) made from bagasse pulp was treated by low-temperature plasma, then reacted grafting polymerization with acrylic acid (AA) to produce super absorbent polymer. The effects of discharge power, plasma treatment time, initiator dosage, acrylic acid dosage, vacuum degree and neutralization ratio on water absorbency and grafting reaction time of the products were studied by single factor experiments. The best process parameters: discharge power = 250 W; plasma treatment time = 90s; m (K2S2O8) : m (CMC) (W/W) = 7:20; m (AA) : m (CMC) (W/W) = (1:9) ~ (1:8); vacuum degree = 300 Pa; neutralization degree = 40%, in which the distilled water absorbency of the product reached its maximum of 509 g/g and the grafting reaction time approached its minimum of 2min. This process has the advantages of simple operation, easy control, high grafting efficiency, short production cycle, low cost and so on, which meet the industrial production requirements of super absorbent polymer.

scholarly journals The IgE Blocking Activity Induced by Dermatophagoides pteronyssinus Subcutaneous Immunotherapy Does Not Correlate with Specific IgA but with IgG4 in both Serum and Saliva

2021 ◽  
pp. 1-14
Author(s):  
Yong He ◽  
Jinling Liu ◽  
Deyu Zhao ◽  
Suqin Zhang ◽  
Guodong Hao ◽  
...  
Keyword(s):  
Treatment Time ◽  
Symptomatic Treatment ◽  
Specific Ige ◽  
Dermatophagoides Pteronyssinus ◽  
Subcutaneous Immunotherapy ◽  
Control Group ◽  
Serum Igg4 ◽  
Specific Igg4 ◽  
Blocking Activity ◽  
Der P 2

<b><i>Background:</i></b> The role of salivary-specific IgG4 and IgA in subcutaneous immunotherapy (SCIT) is not well defined. We aimed to investigate the change of IgG4 and IgA in both serum and saliva and their correlations with IgE-blocking-factor (IgE-BF) during SCIT. <b><i>Method:</i></b> 307 <i>Dermatophagoides pteronyssinus</i> (DP) allergic rhinitis and/or asthma patients were recruited for this study. 286 patients received DP-SCIT for 1 year. Twenty-one patients received only symptomatic treatment. DP-, Der p 1-, and Der p 2-specific IgE in serum, specific-IgG4 and Der p 2-specific IgA1 and IgA2 in both serum and saliva were measured at timepoints 0, 4, and 12 months during DP-SCIT. Correlation between salivary and serological IgG4, IgA, and their correlation with DP-specific IgE-BF measured in serum was evaluated. <b><i>Results:</i></b> During DP-SCIT, the allergen-specific IgG4 in both saliva and serum increased and correlated significantly, the correlation becomes stronger over the treatment time. DP-specific IgE-BF significantly correlated with DP-specific IgG4 in serum (<i>p</i> &#x3c; 0.0001) at different timepoints and in saliva at 12 months of SCIT (<i>p</i> &#x3c; 0.01). No change in Der p 2-specific IgA during DP-SCIT was observed, and the IgA in serum did not correlate with IgA in saliva. There was no correlation between DP IgE-BF and Der p 2-specific IgA in serum or saliva. The control group did not exhibit significant changes in any antibody level measured. <b><i>Conclusion:</i></b> The IgE blocking activity induced by DP-SCIT treatment correlated with specific IgG4 and not IgA. The IgG4 in saliva correlates with serum IgG4 and can be an alternative immunological marker beyond 1 year of SCIT treatment.

Reminiscence: A Nonformal Technique for Improving Cognitive Functioning in the Aged

1983 ◽  
Vol 15 (2) ◽  
pp. 139-149 ◽  
Author(s):  
George A. Hughston ◽  
Sharan B. Merriam
Keyword(s):  
Cognitive Functioning ◽  
Intervention Program ◽  
The Elderly ◽  
Control Group ◽  
Personal Lives ◽  
Treatment Groups ◽  
Central Pennsylvania ◽  
New Material ◽  
Improved Performance ◽  
Housing Complex

This study investigated the effect of a structured reminiscent intervention program upon cognitive functioning of the elderly. The sample consisted of 105 volunteers residing in a public housing complex in central Pennsylvania. Using an experimental design, the volunteers were randomly assigned to one of three treatment groups. One group was given learning tasks to be performed using material from their past personal lives. A second group was asked to perform operations on new material and a control group was pre and posttested but given no treatment. It was found that females in the reminiscent group significantly improved scores of cognitive functioning as measured by the Raven Standard Progressive Matrices. Secondly, compared with the control group, both the reminiscent and new material groups improved performance as a result of the planned learning activities. Both findings suggest that attempts to stimulate cognitive functioning in older people are worth undertaking, and that memories can provide the material for such activities.

scholarly journals Effects of Super-Absorbent Polymer Application on Yield and Yield Components of Rapeseed (Brassica napus L.)

2015 ◽  
Vol 7 (3) ◽  
pp. 361-366 ◽  
Author(s):  
Fariborz SHEKARI ◽  
Abdollah JAVANMARD ◽  
Amin ABBASI
Keyword(s):  
Water Use ◽  
Field Condition ◽  
Block Design ◽  
Embryo Abortion ◽  
Super Absorbent Polymer ◽  
Irrigation Interval ◽  
Randomized Block Design ◽  
Rapeseed Production ◽  
Polymer Application ◽  
Absorbent Polymer

Limitation of water resources and its great impact on agricultural and natural resources play a crucial role in the efficiency of water use. Applying super absorbent polymer to the soil may be one of the methods to minimize the stress of weather dryness in arid and semi-arid regions. In order to evaluate the effects of hydrophilic polymer application on yield and water use efficiency of rapeseed plants, an experiment was conducted under field condition in 2012 at the Research Farm of the Faculty of Agriculture, University of Maragheh. Treatments’ factors were: (i) 3 super absorbent polymers (SAP) (Taravat A200) levels of 0 (without application), 75 and 150 kg ha-1 A200 application, (ii) three irrigation levels of 80, 120 and 180 mm evaporation from class A basin in main plots, (iii) two cultivars ʻHyola 401ʼ and ʻRVSʼ in sub plots as factorial split plot combination based on completely randomized block design with three replications. The results showed that in all of the measured traits within the experiment there were significant differences between SAP levels. Furthermore, increasing irrigation interval led to an increase in a thousand seeds’ weight, but decreased seed yield. Increasing water stress raised seed oil percent and infertile silique and subsequently resulted in reduced oil yield. ʻHyola 401ʼ was more susceptible to embryo abortion compared with ʻRVSʼ. As a conclusion of the research, SAP (A200) application in quantities smaller than 75 kg ha-1 may be recommended for rapeseed production under field condition.

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