The effects of structural defects on the stability of poly(vinyl chloride): A critical review

1987 ◽  
Vol 17 (2) ◽  
pp. 117-129 ◽  
Author(s):  
Jacob B. Adeniyi ◽  
Gerald Scott
Keyword(s):  
Vinyl Chloride ◽  
Critical Review ◽  
Structural Defects ◽  
Poly Vinyl Chloride ◽  
The Stability

Zinc Hydroxystannate-Coated Mineral Grade Mg(OH)2 as Flame-Retardant and Smoke Suppression for Flexible PVC

2013 ◽  
Vol 652-654 ◽  
pp. 481-484 ◽  
Author(s):  
Chun Zheng Wang ◽  
Wei Hong Wu ◽  
Xia Ye ◽  
Lei Liu
Keyword(s):  
Flame Retardant ◽  
Vinyl Chloride ◽  
Smoke Suppression ◽  
Crosslinking Reaction ◽  
X Ray Diffraction ◽  
Limiting Oxygen Index ◽  
Smoke Suppressant ◽  
Poly Vinyl Chloride ◽  
Zinc Hydroxystannate ◽  
The Stability

A zinc hydroxystannate-coated mineral grade Mg(OH)2 (ZHSCMH) was synthesized as flame retardant and smoke suppressant for flexible poly (vinyl chloride). The powder of ZHSCMH was characterized by the x-ray diffraction (XRD) and scanning electron microscopy (SEM). The flame retardancy, smoke suppression and thermal behavior of PVC treated with ZHSCMH and mineral grade Mg(OH)2 were comparative studied by means of limiting oxygen index (LOI), smoke density rating (SDR), thermogravimetry (TG), differential thermogravimetry (DTG) and SEM. The results show that, ZHSCMH can be used as a high effective flame retardant and smoke suppressant for PVC. The flame retardant of ZHSCMH can effectively promote the crosslinking reaction of poly (vinyl chloride) (PVC) in the first stage, and improve the stability of the char residue in the second stage.

Theoretical Study of Thermal Dehydrochlorination of Poly(vinyl chloride) Initiated by Tertiary Chlorine Groupings

1995 ◽  
Vol 60 (8) ◽  
pp. 1303-1309 ◽  
Author(s):  
Jaroslav Burda ◽  
Rudolf Lukáš
Keyword(s):  
Vinyl Chloride ◽  
Structural Defects ◽  
Low Molecular Weight ◽  
Chemical Methods ◽  
Poly Vinyl Chloride ◽  
Quantum Chemical Methods ◽  
Ionic Intermediates ◽  
Detailed Evaluation ◽  
Tertiary Carbon ◽  
Branched Structure

Thermal dehydrochlorination of syndiotactic poly(vinyl chloride) sequences initiated by structural defects possessing chlorine atoms bound on tertiary carbon atoms (branched structures) was theoretically studied on the low-molecular-weight models using the semiempirical quantum chemical methods MNDO and AM1. The results are compared with those obtained previously by studying the dehydrochlorination in syndiotactic sequences without defects. It was found that elimination of the first HCl molecule is much easier in the branched structure. However, this effect fast decreases with dehydrochlorination continuing along the chain due to its distinct localization in the closest vicinity of tertiary carbon atom. A detailed evaluation of possible radical and ionic intermediates revealed that for ionic mechanism of dehydrochlorination the effect of branching is perceptible slightly longer.

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