Dataset Information

When Attempting Chain Extension, Even Without Solvent, It Is Not Possible to Avoid Chojnowski Metathesis Giving D3.

ABSTRACT: A simple, mild and efficient method to prepare HSi- or HOSi-telechelic, high-molecular-weight polydimethylsiloxane polymers (to 41,600 g·mol-1) using the one-shot hydrolysis of MHMH is reported; titration of the water allowed for higher molecular weights (to 153,900 g·mol-1). The "living" character of the chain extension processes was demonstrated by adding a small portion of MHMH and B(C6F5)3 (BCF) to a first formed polymer, which led to a ~2-fold, second growth in molecular weight. The heterogeneous reaction reached completion in less than 30 min, much less in some cases, regardless of whether it was performed neat or 50 wt% in dry toluene; homogeneous reactions in toluene were much slower. The process does not involve traditional redistribution, as judged by the low quantities (<3%) of D4 produced. However, it is not possible to avoid Chojnowski metathesis from MHDDMH giving D3, which occurs competitively with chain extension.

SUBMITTER: Liao M

PROVIDER: S-EPMC7795595 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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When Attempting Chain Extension, Even Without Solvent, It Is Not Possible to Avoid Chojnowski Metathesis Giving D3.

Liao Mengchen M Chen Yang Y Brook Michael A MA

Molecules (Basel, Switzerland) 20210105 1

A simple, mild and efficient method to prepare HSi- or HOSi-telechelic, high-molecular-weight polydimethylsiloxane polymers (to 41,600 g·mol-1) using the one-shot hydrolysis of MHMH is reported; titration of the water allowed for higher molecular weights (to 153,900 g·mol-1). The "living" character of the chain extension processes was demonstrated by adding a small portion of MHMH and B(C6F5)3 (BCF ...[more]

PMID: 33466286

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Project description:BackgroundThe clinical form of depersonalization affects approximately 1%-2% of the adult population. This study aimed to describe the symptoms of depersonalization in a non-clinical sample and to operationalize depersonalization as a regulatory mechanism. This article introduces the Depersonalization Mechanism Scale, 41-item measure developed to assess one's tendency for depersonalization in response to overstimulation. The aim of the study is to explore how depersonalization mechanism is associated with cognitive and behavioral emotion regulation strategies, depression, and anxiety.MethodThe study included a sample of 300 Polish adults (149 men) from the general population, ranging in age from 18 to 60. Participants were administered the following questionnaires: Depersonalization Mechanism Scale (DMS), Behavioral Emotion Regulation Questionnaire (BERQ), Cognitive Emotion Regulation Questionnaire (CERQ), Occupational Depression Inventory (ODI), Patient Health Questionnaire (PHQ), and Trait Anxiety Scale (SL-C).ResultsAn exploratory factor analysis revealed a two-factor structure of Depersonalization Mechanism Scale, with very high reliability coefficients for both subscales and full scale. A regression analysis revealed that depersonalization mechanism is a significant predictor of depressive symptoms. Depersonalization mechanism is strongly correlated with maladaptive regulation strategies such as withdrawal, ignoring, rumination, catastrophizing, self-blame, and blaming others. Weaker but significant connections were identified with certain adaptive strategies: acceptance, positive refocusing, putting into perspective, and seeking social support. Women were more prone to depersonalization than men.ConclusionsFurther research on depersonalization in non-clinical samples may improve understanding of this mechanism in the general population. This knowledge, combined with greater education about non-clinical forms of depersonalization, may support preventive programs against depression and professional assistance for people facing acute or chronic stressful life events.

Dataset Information

When Attempting Chain Extension, Even Without Solvent, It Is Not Possible to Avoid Chojnowski Metathesis Giving D3.

Publications

When Attempting Chain Extension, Even Without Solvent, It Is Not Possible to Avoid Chojnowski Metathesis Giving D<sub>3</sub>.

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